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1. (+)- and (-)-Eurotone A: a Pair of Enantiomeric Polyketide Dimers from a Marine-Derived Fungus Eurotium sp. SCSIO F452

Author:
Wei-Mao Zhong; Jun-Feng Wang; Xiao-Yi Wei; Qi Zeng; Xia-Yu Chen; Yao Xiang; Xin-Peng Tian; Si Zhang; Li-Juan Long; Fa-Zuo Wang
Source:
Tetrahedron letters 2019 pp. -
ISSN:
0040-4039
Subject:
Eurotium; X-ray diffraction; antioxidant activity; biochemical pathways; dimerization; enantiomers; marine fungi; polyketides; quantum mechanics; spectroscopy
Abstract:
... (±)-Eurotone A [(±)-1], a pair of new enantiomeric polyketide dimers, as well as six known biogenetically related polyketides (2-7) were isolated from a marine-derived fungus Eurotium sp. SCSIO F452. Their structures were determined by comprehensive spectroscopic methods, X-ray diffraction and quantum chemical calculations. Compound 1 represented the first pair of spiro-dihydrobenzanthracene enant ...
DOI:
10.1016/j.tetlet.2019.05.025

2. (+)- and (−)-Alternarilactone A: Enantiomers with a Diepoxy-Cage-like Scaffold from an Endophytic Alternaria sp.

Author:
Jian-Wei Tang; Hou-Chao Xu; Wei-Guang Wang; Kun Hu; Yuan-Fei Zhou; Rong Chen; Xiao-Nian Li; Xue Du; Han-Dong Sun; Pema-Tenzin Puno
Source:
Journal of natural products 2019 v.82 no.4 pp. 735-740
ISSN:
1520-6025
Subject:
Alternaria; X-ray diffraction; enantiomers; endophytes; fungi; moieties; nuclear magnetic resonance spectroscopy; probability analysis; quantum mechanics; risk
Abstract:
... The enantiomers (+)- and (−)-alternarilactone A (1), the first examples of dibenzo-α-pyrones bearing a diepoxy-cage-like moiety, were isolated from the endophytic fungus Alternaria sp. hh930. The deficiency in ¹H–¹H COSY and HMBC correlations caused by the highly oxidized caged system of 1 and the deceptive and ambiguous signals such as “W” couplings in NMR data increased the risk of structure mis ...
DOI:
10.1021/acs.jnatprod.8b00571

3. (+)- and (−)-Petromyroxols: Antipodal Tetrahydrofurandiols from Larval Sea Lamprey (Petromyzon marinus L.) That Elicit Enantioselective Olfactory Responses

Author:
Li Ke; Huertas Mar; Brant Cory; Chung-Davidson Yu-Wen; Bussy Ugo; Hoye Thomas R.; Li Weiming
Source:
Organic letters 2015 v.17 no.2 pp. 286-289
ISSN:
1523-7052
Subject:
Petromyzon marinus; chemical reactions; chromatography; enantiomers; enantioselectivity; fatty acids; larvae; synthetic products; tetrahydrofuran
Abstract:
... (+)- and (−)-Petromyroxol [(+)-1 and (−)-1, respectively], two novel tetrahydrofuran (THF)-diol fatty acid enantiomers, were isolated from water conditioned with larval sea lamprey. We herein describe their isolation and subsequent resolution using chiral chromatography. The absolute configuration of each enantiomer was determined by a combination of Mosher ester analysis and comparison with relat ...
DOI:
10.1021/ol5033893

4. (+)- and (−)-Preuisolactone A: A Pair of Caged Norsesquiterpenoidal Enantiomers with a Tricyclo[4.4.0¹,⁶.0²,⁸]decane Carbon Skeleton from the Endophytic Fungus Preussia isomera

Author:
Lu-Lin Xu; Hai-Li Chen; Ping Hai; Yuan Gao; Chuan-Dong Xie; Xiao-Long Yang; Ikuro Abe
Source:
Organic letters 2019 v.21 no.4 pp. 1078-1081
ISSN:
1523-7052
Subject:
Micrococcus luteus; Preussia; X-ray diffraction; antibacterial properties; biochemical pathways; carbon; chemical reactions; decane; enantiomers; endophytes; fungi; spectroscopy
Abstract:
... A pair of enantiomeric norsesquiterpenoids, (+)- and (−)-preuisolactone A (1) [(+)-1 and (−)-1)] featuring an unprecedented tricyclo[4.4.0¹,⁶.0²,⁸]decane carbon scaffold were isolated from Preussia isomera. Their structures were determined by spectroscopic and computed methods and X-ray crystallography. Compounds (+)-1 and (−)-1 are two rare naturally occurring sesquiterpenoidal enantiomers. A pla ...
DOI:
10.1021/acs.orglett.8b04123

5. (+)- and (−)-Spongiterpene, a pair of new valerenane sesquiterpene enantiomers from the marine sponge Spongia Sp.

Author:
Yong-Qian Liang; Xiao-Jian Liao; Bing-Xin Zhao; Shi-Hai Xu
Source:
Natural product research 2021 v.35 no.13 pp. 2178-2183
ISSN:
1478-6427
Subject:
Spongia; X-ray diffraction; cytotoxicity; enantiomers; quantum mechanics; research; sesquiterpenoids; spectral analysis
Abstract:
... (+)- and (−)-Spongiterpene [(+)-1 and (−)-1], a pair of new valerenane sesquiterpene enantiomers, along with four known compounds (2-5) were isolated from the marine sponge Spongia sp. The structures of (+)-1 and (−)-1 including absolute configurations were determined by spectroscopic analysis, quantum chemical calculation and X-ray diffraction. Compounds (+)-1 and (−)-1 were the first examples of ...
DOI:
10.1080/14786419.2019.1666384

6. (+)- and (−)-trichodermatrione A: a pair of enantiomers with a cyclobutane-containing skeleton from the endophytic fungus Trichoderma sp. EFT2

Author:
Wei Yan; Wenxia Ji; Chuan Ping; Tianyi Zhang; Yu Li; Biao Wang; Tianyu Chen; Bo He; Yonghao Ye
Source:
Phytochemistry 2022 v.196 pp. 113087
ISSN:
0031-9422
Subject:
Euonymus fortunei; Trichoderma; X-ray diffraction; Xanthomonas oryzae pv. oryzae; enantiomers; endophytes; fungi; plant biochemistry; skeleton
Abstract:
... (±)-trichodermatrione A, a pair of cyclobutane-containing enantiomers with an undescribed tricyclic 6/4/6 skeleton, was isolated from Trichoderma sp. EFT2, an endophytic fungus from Euonymus fortunei (Turcz.) Hand.-Mazz (Celastraceae). The racemates were separated by chiral HPLC with the structures elucidated by a combination of MS, NMR, ECD calculation and X-ray crystallography analyses. (±)- tri ...
DOI:
10.1016/j.phytochem.2022.113087

7. (+)-/(−)-Prunomarin A and (+)-pestalactone B, three new isocoumarin derivatives from the endophytic fungus Phomopsis prunorum

Author:
Xue-Qing Zhang; Zhen-Hong Lu; Gui-Ru Xia; Wen-Min Song; Zhi-Yong Guo; Peter Proksch
Source:
Tetrahedron letters 2021 v.75 pp. 153205
ISSN:
0040-4039
Subject:
Amaranthus retroflexus; Diaporthe; X-ray diffraction; anti-inflammatory activity; enantiomers; endophytes; fungi; phytotoxicity; spectral analysis
Abstract:
... Three pairs of isocoumarin enantiomers, (±)-prunomarin A (1), (±)-pestalactone B (2), and (±)-3, including three new compounds, (+)-/(−)-1 and (+)-2, were isolated from the endophytic fungus Phomopsis prunorum (F4-3). These enantiomeric pairs were existed as partial racemates and were achieved by chiral-HPLC separation. Their structures were elucidated by comprehensive spectroscopic data, X-ray di ...
DOI:
10.1016/j.tetlet.2021.153205

8. (+)-Menthol and Its Hydroxy Derivatives, Novel Fungal Monoterpenols from the Fusicoccin-producing Fungi, Phomopsis amygdali F6a and Niigata 2

Author:
Takeshi SASSA; Hiromichi KENMOKU; Mitsuyoshi SATO; Tetsuya MURAYAMA; Nobuo KATO
Source:
Bioscience, biotechnology, and biochemistry 2003 v.67 no.3 pp. 475-479
ISSN:
1347-6947
Subject:
Diaporthe amygdali; Mentha piperita nothosubsp. piperita; biosynthesis; biotechnology; diterpenoids; enantiomers; fermentation; fungi; fusicoccin; glucosides; metabolites; monoterpenoids
Abstract:
... In our search for new fusicoccins of unique diterpene glucosides from Phomopsis amygdali, we found that a fragrant substance was formed in the early stage of fusicoccin fermentation. This fragrant constituent was isolated and identified as (+)-menthol, which is a novel fungal metabolite as the enantiomer of well-known peppermint (−)-menthol. (+)-7-Hydroxymenthol and new (+)-(6S)-hydroxymenthol wer ...
DOI:
10.1271/bbb.67.475

9. (+)-Methyl Jasmonate-Induced Bioformation of Myricetin, Quercetin and Kaempferol in Red Raspberries

Author:
Pena Moreno, Fernando de la; Blanch, Gracia Patricia; Ruiz del Castillo, Maria Luisa
Source:
Journal of agricultural and food chemistry 2010 v.58 no.22 pp. 11639-11644
ISSN:
0021-8561
Subject:
methyl jasmonate; myricetin; quercetin; kaempferol; raspberries; postharvest treatment; food processing quality; food analysis; fruit composition; fruit quality; enantiomers
Abstract:
... The effect of postharvest treatment with enantiomers of methyl jasmonate (MJ) in conjunction with ethanol on bioformation of myricetin, quercetin and kaempferol in red raspberry was studied. For comparison, postharvest treatment with the commercial stereoisomeric mixture of MJ in conjunction with ethanol was simultaneously accomplished. The levels obtained were contrasted with those determined in ...
DOI:
10.1021/jf102875b

10. (+)-Meyeniins A–C, Novel Hexahydroimidazo[1,5-c]thiazole Derivatives from the Tubers of Lepidium meyenii: Complete Structural Elucidation by Biomimetic Synthesis and Racemic Crystallization

Author:
Zhou Min; Ma Hang-Ying; Liu Zhi-Hua; Yang Guang-Yu; Du Gang; Ye Yan-Qing; Li Gan-Peng; Hu Qiu-Fen
Source:
Journal of agricultural and food chemistry 2017 v.65 no.9 pp. 1887-1892
ISSN:
1520-5118
Subject:
Lepidium meyenii; X-ray diffraction; biomimetic synthesis; circular dichroism spectroscopy; condensation reactions; crystallization; crystals; cytotoxicity; dietary supplements; enantiomers; functional foods; human cell lines; inhibitory concentration 50; neoplasms; thiazoles; tubers; China
Abstract:
... (+)-Meyeniins A–C (1–3), a novel class of sulfur-containing hexahydroimidazo[1,5-c]thiazole derivatives, were isolated from the tubers of Lepidium meyenii (maca) cultivated in Lijiang, Yunnan province, China. Guided by their biosynthetic hypothesis, a stereocontrolled biomimetic synthesis of meyeniins A–C and their individual enantiomers was efficiently accomplished by a combination of a condensat ...
DOI:
10.1021/acs.jafc.6b05805

11. (-)-Germacrene D receptor neurones in three species of heliothine moths: structure-activity relationships

Author:
Stranden, M.; Liblikas, I.; Konig, W.A.; Almaas, T.J.; Borg-Karlson, A.K.; Mustaparta, H.
Source:
Journal of comparative physiology 2003 v.189 no.7 pp. 563-577
ISSN:
0340-7594
Subject:
Heliothis virescens; Helicoverpa armigera; Helicoverpa assulta; antennae; olfactory receptors; sensory neurons; sesquiterpenoids; enantiomers; structure-activity relationships; electrophysiology; host plants; volatile compounds; sensilla; neural pathways; moths; insect physiology
Abstract:
... Specificity of olfactory receptor neurones plays an important role in food and host preferences of a species, and may have become conserved or changed in the evolution of polyphagy and oligophagy. We have identified a major type of plant odour receptor neurones responding to the sesquiterpene germacrene D in three species of heliothine moths, the polyphagous Heliothis virescens and Helicoverpa arm ...
DOI:
10.1007/s00359-003-0434-y
PubMed:
12827423

12. (1R,2R)-DPEN-derived triazolium salts for enantioselective oxodiene Diels–Alder reactions

Author:
Zi-Qiang Rong; Min-Qiang Jia; Shu-Li You
Source:
Tetrahedron 2011 v.67 no.48 pp. 9329-9333
ISSN:
0040-4020
Subject:
chemical reactions; enantiomers; organic compounds; salts
Abstract:
... Enantioselective oxodiene Diels–Alder reactions catalyzed by (1R,2R)-DPEN-derived triazolium salts were realized successfully. With 0.5 mol % of (1R,2R)-DPEN-derived triazolium salt C and 150 mol % of Et₃N, the reactions of various α-chloroaldehydes (α-bromoaldehyde) with substituted enones led to 3,4-dihydropyridinones and their derivatives in good yields, diastereoselectivities, and enantioselec ...
DOI:
10.1016/j.tet.2011.09.129

13. (1S,3R)-cis-Chrysanthemyl Tiglate: Sex Pheromone of the Striped Mealybug, Ferrisia virgata

Author:
Jun Tabata; Ryoko T. Ichiki
Source:
Journal of chemical ecology 2017 v.43 no.8 pp. 745-752
ISSN:
0098-0331
Subject:
Ferrisia virgata; adults; alcohols; arthropods; bioassays; carboxylic esters; enantiomers; gas chromatography-mass spectrometry; greenhouses; high performance liquid chromatography; insecticidal properties; insects; males; nuclear magnetic resonance spectroscopy; pyrethrins; sex pheromones; trapping
Abstract:
... Derivatives of 2,2-dimethyl-3-(2-methylprop-1-enyl)cyclopropanecarboxylic acid (chrysanthemic acid) are classic natural pyrethroids discovered in pyrethrum plants and show insecticidal activity. Chrysanthemic acid, with two asymmetric carbons, has four possible stereoisomers, and most natural pyrethroids have the (1R,3R)-trans configuration. Interestingly, chrysanthemic acid–related structures are ...
DOI:
10.1007/s10886-017-0879-z

14. (2R,3S)-2,3-Octanediol, a Female-Produced Sex Pheromone of Megopis costipennis (Coleoptera: Cerambycidae: Prioninae)

Author:
Jacob D. Wickham; Jocelyn G. Millar; Lawrence M. Hanks; Yunfan Zou; Joseph C. H. Wong; Rhett D. Harrison; Yi Chen
Source:
Environmental entomology 2016 v.45 no.1 pp. 223-228
ISSN:
1938-2936
Subject:
Cerambycidae; antennae; bait traps; enantiomers; females; field experimentation; males; screening; sex attractants; sex pheromones; China
Abstract:
... During field screening trials of a number of known cerambycid pheromones in China, males of Megopis costipennis (White) (Coleoptera: Cerambycidae: Prioninae: Callipogonini) were found to be specifically attracted to racemic anti-2,3-octanediol, suggesting that one of the enantiomers of this compound might be a female-produced sex pheromone of this species. Analysis of volatiles produced by beetles ...
DOI:
10.1093/ee/nvv176

15. (2S,12Z)-2-Acetoxy-12-heptadecene: Major Sex Pheromone Component of Pistachio Twig Borer, Kermania pistaciella[Erratum: 2007 Feb., v. 33, no. 2, p. 447-448.]

Author:
Gries, R.; Khaskin, G.; Daroogheh, H.; Mart, C.; Karadag, S.; Er, M.K.; Britton, R.; Gries, G.
Source:
Journal of chemical ecology 2006 v.32 no.12 pp. 2667-2677
ISSN:
0098-0331
Subject:
Lepidoptera; boring insects; pheromone glands; sex pheromones; chemical composition; enantiomers; antennae; electrophysiology; electroantennography; synthesis; pheromone traps; trapping; Pistacia vera; pistachios; Turkey (country)
Abstract:
... The sex pheromone of the pistachio twig borer, Kermania pistaciella (Lepidoptera: Oinophilidae), one of the most important insect pests of pistachio, Pistacia vera, in Turkey and Iran, was identified. In gas chromatographic-electroantennographic detection (GC-EAD) and GC-mass spectrometric analyses of pheromone gland extracts of female K. pistaciella from Turkey, (2S,12Z)-2-acetoxy-12-heptadecene ...
DOI:
10.1007/s10886-006-9190-0

16. (2S,8Z)-2-Butyroxy-8-heptadecene: Major Component of the Sex Pheromone of Chrysanthemum Gall Midge, Rhopalomyia longicauda

Author:
Liu, Ya-Jia; Hall, David; Cross, Jerry; Farman, Dudley; Amarawardana, Lakmali; Liu, Qing-Ran; He, Xiong-Kui
Source:
Journal of chemical ecology 2009 v.35 no.6 pp. 715-723
ISSN:
0098-0331
Subject:
Rhopalomyia; midges; sex pheromones; sex attractants; chemical composition; volatile compounds; enantiomers; antennae; electroantennography; synthesis; trapping; pheromone traps; Chrysanthemum morifolium; galls; China
Abstract:
... The sex pheromone of the chrysanthemum gall midge, Rhopalomyia longicauda (Diptera: Cecidomyiidae), the most important insect pest in commercial plantations of chrysanthemum, Dendranthema morifolium (Ramat.) Tzvel., in China, was identified, synthesized, and field-tested. Volatile chemicals from virgin females and males were collected on Porapak in China and sent to the United Kingdom for analysis ...
DOI:
10.1007/s10886-009-9647-z
PubMed:
19554372

17. (3,3″)-Linked Biflavanones from Ouratea spectabilis and Their Effects on the Release of Proinflammatory Cytokines in THP-1 Cells

Author:
Marina P. Rocha; Priscilla R. V. Campana; Rodrigo M. Pádua; José D. Souza Filho; Daneel Ferreira; Fernão C. Braga
Source:
Journal of natural products 2020 v.83 no.6 pp. 1891-1898
ISSN:
1520-6025
Subject:
anti-inflammatory agents; bark extracts; cardiovascular diseases; chemokine CCL2; circular dichroism spectroscopy; enantiomers; ethers; inhibitory concentration 50; interleukin-1beta; spectral analysis; tumor necrosis factors; Brazil
Abstract:
... Ouratea spectabilis is an arborous species traditionally used in Brazil as an anti-inflammatory agent. Four new (3,3″)-linked biflavanone O-methyl ethers, named ouratein A (1), B (2), C (3), and D (4), were isolated from the bark extract of the species. Ouratein A (1) is an enantiomer of neochamagesmine A, which has never been described before. The structures were elucidated by extensive spectrosc ...
DOI:
10.1021/acs.jnatprod.0c00074

18. (3R,6E)-nerolidol, a fertility-related volatile secreted by the queens of higher termites (Termitidae: Syntermitinae)

Author:
Jana Havlíčková; Klára Dolejšová; Michal Tichý; Vladimír Vrkoslav; Blanka Kalinová; Pavlína Kyjaková; Robert Hanus
Source:
Zeitschrift für Naturforschung 2019 v.74 no.9-10 pp. 251-264
ISSN:
1865-7125
Subject:
Termitidae; abdomen; alcohols; antennae; eggs; enantiomers; headspace analysis; hemolymph; long term experiments; reproduction; sesquiterpenoids; social insects; tissues
Abstract:
... The queens of advanced social insects maintain their reproductive monopoly by using exocrine chemicals. The chemistry of these “queen pheromones” in termites is poorly known. We show that primary queens of four higher termites from the subfamily Syntermitinae (Embiratermes neotenicus, Silvestritermes heyeri, Labiotermes labralis, and Cyrilliotermes angulariceps) emit significant amounts of the ses ...
DOI:
10.1515/znc-2018-0197

19. (3Z,6Z,9Z)-nonadecatriene and enantiomers of (3Z,9Z)-cis-6,7-epoxy-nonadecadiene as sex attractants for two geometrid and one noctuid moth species

Author:
Millar, J.G.; Giblin, M.; Barton, D.; Underhill, E.W.
Source:
Journal of chemical ecology 1990 v.16 no.7 pp. 2153-2166
ISSN:
0098-0331
Subject:
Noctuidae; sex attractants; chemical composition; enantiomers; synergism; sex pheromones; insect control
Abstract:
... Sex attractants for the geometrid moths Eufidonia convergaria and Caripeta angustiorata, and the noctuid moth Rivula propinqualis have been elucidated during field screening of a series of (3Z,6Z,9Z)-triene hydrocarbons (C17-22), and the racemic and enantiomerically enriched monoepoxydienes derived from those hydrocarbons. Biologically active compounds were identified by a combination of field tes ...
DOI:
10.1007/BF01026927
PubMed:
24264083

20. (4+1) vs (4+2): Catalytic Intramolecular Coupling between Cyclobutanones and Trisubstituted Allenes via C–C Activation

Author:
Zhou Xuan; Dong Guangbin
Source:
Journal of the American Chemical Society 2015 v.137 no.42 pp. 13715-13721
ISSN:
1520-5126
Subject:
carbon; enantiomers; ligands
Abstract:
... Herein we describe a rhodium-catalyzed (4+1) cyclization between cyclobutanones and allenes, which provides a distinct [4.2.1]-bicyclic skeleton containing two quaternary carbon centers. The reaction involves C–C activation of cyclobutanones and employs allenes as a one-carbon unit. A variety of functional groups can be tolerated, and a diverse range of polycyclic scaffolds can be accessed. Excell ...
DOI:
10.1021/jacs.5b09799
PubMed:
26440740
PubMed Central:
PMC4884657

21. (6R, 10R)-6,10,14-Trimethylpentadecan-2-one, a Dominant and Behaviorally Active Component in Male Orchid Bee Fragrances

Author:
Eltz, Thomas; Hedenström, Erik; Bång, Joakim; Wallin, Erika A.; Andersson, Jimmy
Source:
Journal of chemical ecology 2010 v.36 no.12 pp. 1322-1326
ISSN:
0098-0331
Subject:
Euglossa; Orchidaceae; acetone; bioassays; enantiomers; flowers; males; molecular weight; odors; tibia; Mexico; Panama
Abstract:
... 6,10,14-Trimethylpentadecan-2-one (Hexahydrofarnesyl acetone; HHA) previously has been found to be a major component in tibial fragrances of male orchid bees, Euglossa spp. HHA is a chiral molecule with four possible stereoisomers, (6R, 10R)-, (6R, 10S)-, (6S, 10R)-, and (6S, 10S)-6,10,14-trimethylpentadecan-2-one. In the present study, we characterized HHA extracted from Euglossa as the pure enan ...
DOI:
10.1007/s10886-010-9873-4
PubMed:
20953677

22. (6Z,9Z-3R,4S)-epoxy-heptadecadiene: major sex pheromone component of the larch looper, Semiothisa sexmaculata (Packard) (Lepidoptera: Geometridae)

Author:
Gries, G.; Gries, R.; Underhill, E.W.; Humble, L.
Source:
Journal of chemical ecology 1993 v.19 no.4 pp. 843-850
ISSN:
0098-0331
Subject:
sex pheromones; chemical composition; enantiomers; insect control
Abstract:
... Gas chromatographic-electroantennographic analysis (GC-EAD) of female larch looper, Semiothisa sexmaculata (Packard), gland extracts revealed two EAD-active compounds. Retention index calculations, GC-mass spectroscopy in selected ion monitoring mode, and GC-EAD analysis of authentic standards identified the compounds as (3Z,6Z,9Z)-heptadecatriene (3Z,6Z,9Z-17:H) and (6Z,9Z)-cis-3,4-epoxy-heptadec ...
DOI:
10.1007/BF00985014
PubMed:
24249023

23. (9R)-9-Hydroxystearate-Functionalized Hydroxyapatite as Antiproliferative and Cytotoxic Agent toward Osteosarcoma Cells.

Author:
Boanini Elisa; Torricelli Paola; Boga Carla; Micheletti Gabriele; Cassani Maria Cristina; Fini Milena; Bigi Adriana
Source:
Langmuir 2016 v.32 no.1 pp. 188-194
ISSN:
1520-5827
Subject:
Dimorphotheca sinuata; adsorption; biocompatible materials; caspase-3; cell proliferation; cytotoxicity; enantiomers; hydroxyapatite; in vitro studies; lactate dehydrogenase; nanocrystals; neoplasm cells; osteosarcoma; seeds; therapeutics; tumor necrosis factor-alpha; viability
Abstract:
... The possibility to functionalize calcium phosphates with bioactive agents is a promising strategy to design innovative biomaterials for bone repair able to couple the bioactive properties of the inorganic compounds with the therapeutic effect of the functionalizing agent. The R enantiomer of the 9-hydroxystearic acid, (9R)-9-HSA, produced from Dimorphotheca sinuata L. seeds, has proven to act as a ...
DOI:
10.1021/acs.langmuir.5b03754

24. (Chiral) lithium–(magnesium–)zinc and lithium–cobalt combinations as dual reagents for aromatic deproto-metalation and aryl transfer to aldehydes

Author:
David Tilly; Katia Snégaroff; Gandrath Dayaker; Floris Chevallier; Philippe C. Gros; Florence Mongin
Source:
Tetrahedron 2012 v.68 no.42 pp. 8761-8766
ISSN:
0040-4020
Subject:
alcohols; aldehydes; chemical reactions; enantiomers; iodine; temperature; tetrahydrofuran; zinc
Abstract:
... The deprotonating ability of mixed lithium–zinc or lithium–magnesium–zinc combinations containing amido and alkyl ligands in tetrahydrofuran were compared using anisole as substrate and iodine to quantitatively trap the formed arylmetal species. The results showed that the deprotonating ability is hampered if a Grignard reagent is employed to introduce the alkyl ligand, and is reduced when 2,2,6,6 ...
DOI:
10.1016/j.tet.2012.08.008

25. (E)- and (Z)-6-nonen-2-one: biosynthetic precursors of endo- and exo-brevicomin in two bark beetles (Coleoptera: Scolytidae)

Author:
Vanderwel, D.; Gries, G.; Singh, S.M.; Borden, J.H.; Oehlschlager, A.C.
Source:
Journal of chemical ecology 1992 v.18 no.8 pp. 1389-1404
ISSN:
0098-0331
Subject:
Dryocoetes confusus; enantiomers; biosynthesis; Dendroctonus ponderosae; pheromones; metabolites; insect control
Abstract:
... The ability of (E)- and (Z)-6-nonen-2-one to serve as precursors of the common scolytid pheromones endo- and exo-brevicomin was examined in vivo. When mountain pine beetles (MPB), Dendroctonus ponderosae Hopkins, or western balsam bark beetles (WBBB), Dryocoetes confusus Swaine, were exposed to [6,7-D2](E)-6-nonen-2-one, the endo-brevicomin produced was enriched with two deuterium atoms per molecu ...
DOI:
10.1007/BF00994364
PubMed:
24254214

26. (Guanidine)copper Complex-Catalyzed Enantioselective Dynamic Kinetic Allylic Alkynylation under Biphasic Condition

Author:
Xi-Yang Cui; Yicen Ge; Siu Min Tan; Huan Jiang; Davin Tan; Yunpeng Lu; Richmond Lee; Choon-Hong Tan
Source:
Journal of the American Chemical Society 2018 v.140 no.27 pp. 8448-8455
ISSN:
1520-5126
Subject:
Lewis bases; X-ray diffraction; alkynes; bromides; catalysts; copper; enantiomers; enantioselectivity; guanidinium; ligands; mass spectrometry; organobromine compounds
Abstract:
... Highly enantioselective allylic alkynylation of racemic bromides under biphasic condition is furnished in this report. This approach employs functionalized terminal alkynes as pro-nucleophiles and provides 6- and 7-membered cyclic 1,4-enynes with high yields and excellent enantioselectivities (up to 96% ee) under mild conditions. Enantioretentive derivatizations highlight the synthetic utility of ...
DOI:
10.1021/jacs.7b12806

27. (NHC)Si═C═N–R: A Two-Coordinated Si⁰-Isocyanide Compound as Si(NHC) Transfer Reagent

Author:
Surendar Karwasara; Leonard R. Maurer; Benjamin Peerless; Gregor Schnakenburg; Ujjal Das; Alexander C. Filippou
Source:
Journal of the American Chemical Society 2021 v.143 no.36 pp. 14780-14794
ISSN:
1520-5126
Subject:
carbenes; enantiomers; geometry; heterocyclic nitrogen compounds; optical isomerism; skeleton; stoichiometry
Abstract:
... Experimental and theoretical studies are reported of the first two-coordinated Si⁰-isocyanide compound (SIDipp)Si═C═N–Arᴹᵉˢ (1: SIDipp (NHC) = C[N(Dipp)CH₂]₂, Arᴹᵉˢ = 2,6-dimesitylphenyl), supported by an N-heterocyclic carbene (NHC). A Si atom economic two-step synthesis of 1 involves a 2e reduction of the isocyanide-stabilized silyliumylidene salt [SiBr(CNArᴹᵉˢ)(SIDipp)][B(ArF)₄] (2[B(ArF)₄], Ar ...
DOI:
10.1021/jacs.1c06628

28. (P)/(M)-corinepalensin A, a pair of axially chiral prenylated bicoumarin enantiomers with a rare C-5C-5′ linkage from the twigs of Coriaria nepalensis

Author:
Lin Chen; Gui-Hua Tang; Fu-Liang Guo; Wei Li; Jun-Sheng Zhang; Bo Liu; Sheng Yin
Source:
Phytochemistry 2018 v.149 pp. 140-145
ISSN:
0031-9422
Subject:
Coriaria; asthma; branches; chemical bonding; coumarin; drugs; enantiomers; inhibitory concentration 50; spectroscopy
Abstract:
... A pair of undescribed bicoumarin enantiomers, (P)/(M)-corinepalensin A, two undescribed prenylated coumarins, corinepalensins B and C, along with ten known coumarins were isolated from the twigs of Coriaria nepalensis. (P)/(M)-corinepalensin A feature a rare C-5C-5′ axially chiral linkage between two prenylated coumarin monomers. Their structures were determined by a combination of spectroscopic m ...
DOI:
10.1016/j.phytochem.2018.02.012

29. (R)-5-[(1R,2R)-1-Ethyl-2- (4-oxocyclohexyl)butyl]oxepan-2-one, an Enantiopure ‘Pseudosteroid′

Author:
Brigitte Kluess; Wolfgang Kreiser; Tony Sukri; Wolfgang Poll; Hartmut Wunderlich
Source:
Zeitschrift für Naturforschung 2014 v.61 no.1 pp. 111-112
ISSN:
0932-0776
Subject:
androgens; crystal structure; diastereomers; enantiomers; estrogens; optical isomerism
Abstract:
... The title compound C₁₈H₃₀O₃ represents an optically pure member of a class of ‘pseudosteroids’, i. e. perhydrostilbene derivatives which mimic steroidal androgens (in the way like hexestrols or stilbestrols serve to substitute natural estrogens). The molecule 2 is characterized by three consecutive chiral centers leading to eight possible stereoisomers including four diastereomers. All enantiomers ...
DOI:
10.1515/znb-2006-0122

30. (R)-Desmolactone, A Female-produced Sex Pheromone Component of the Cerambycid Beetle Desmocerus californicus californicus (subfamily Lepturinae)

Author:
Ann M. Ray; Ian P. Swift; J. Steven McElfresh; Ronald L. Alten; Jocelyn G. Millar
Source:
Journal of chemical ecology 2012 v.38 no.2 pp. 157-167
ISSN:
0098-0331
Subject:
Coleoptera; antennae; bioassays; enantiomers; females; gases; headspace analysis; males; sex pheromones
Abstract:
... We report the identification, synthesis, and field bioassays of a female-produced sex attractant pheromone for the cerambycid beetle Desmocerus californicus californicus Horn. Headspace volatiles from females contained a sex-specific compound, (R)-desmolactone [(4R,9Z)-hexadec-9-en-4-olide], which elicited strong responses from the antennae of adult males in coupled gas chromatography-electroanten ...
DOI:
10.1007/s10886-012-0070-5
PubMed:
22350519

31. (R)-PFI-2 is a potent and selective inhibitor of SETD7 methyltransferase activity in cells

Author:
Dalia Barsyte-Lovejoy; Fengling Li; Menno J. Oudhoff; John H. Tatlock; Aiping Dong; Hong Zeng; Hong Wu; Spencer A. Freeman; Matthieu Schapira; Guillermo A. Senisterra; Ekaterina Kuznetsova; Richard Marcellus; Abdellah Allali-Hassani; Steven Kennedy; Jean-Philippe Lambert; Amber L. Couzens; Ahmed Aman; Anne-Claude Gingras; Rima Al-Awar; Paul V. Fish; Brian S. Gerstenberger; Lee Roberts; Caroline L. Benn; Rachel L. Grimley; Mitchell J. S. Braam; Fabio M. V. Rossi; Marius Sudol; Peter J. Brown; Mark E. Bunnage; Dafydd R. Owen; Colby Zaph; Masoud Vedadi; Cheryl H. Arrowsmith
Source:
Proceedings of the National Academy of Sciences of the United States of America 2014 v.111 no.35 pp. 12853-12858
ISSN:
0027-8424
Subject:
dose response; enantiomers; fibroblasts; genes; humans; lysine; methyltransferases; mice; signal transduction; transcription (genetics)
Abstract:
... SET domain containing (lysine methyltransferase) 7 (SETD7) is implicated in multiple signaling and disease related pathways with a broad diversity of reported substrates. Here, we report the discovery of (R)-PFI-2—a first-in-class, potent (K ᵢᵃᵖᵖ = 0.33 nM), selective, and cell-active inhibitor of the methyltransferase activity of human SETD7—and its 500-fold less active enantiomer, (S)-PFI-2. (R) ...
DOI:
10.1073/pnas.1407358111
PubMed:
25136132
PubMed Central:
PMC4156762

32. (R)-nicotine biosynthesis, metabolism and translocation in tobacco as determined by nicotine demethylase mutants

Author:
Bin Cai; Anne M. Jack; Ramsey S. Lewis; Ralph E. Dewey; Lowell P. Bush
Source:
Phytochemistry 2013 v.95 pp. 188-196
ISSN:
0031-9422
Subject:
biosynthesis; enantiomers; leaves; mutants; nicotine; nornicotine; roots; rootstocks; scions; tobacco
Abstract:
... Nicotine is a chiral compound and consequently exists as two enantiomers. Since (R)-nicotine consists of less than 0.5% of total nicotine pool in tobacco, few investigations relating to (R)-nicotine have been reported. However, previous studies of nicotine demethylases suggested there was substantial amount of (R)-nicotine at synthesis in the tobacco plant. In this study, the accumulation and tran ...
DOI:
10.1016/j.phytochem.2013.06.012
PubMed:
23849545

33. (R)‐Tonkafuranone and related compounds: Improved synthesis, stereochemical purity in nature, and bioactivities of the pure enantiomers

Author:
Matthias Hoffmann; Jean‐Pierre Mufusama Koy Sita; Carolin Kleider; Sandra Gunesch; Bruno Rothmund; Leane Lehmann; Gerhard Bringmann; Michael Decker
Source:
Flavour and fragrance journal 2019 v.34 no.5 pp. 329-338
ISSN:
0882-5734
Subject:
Bursera; Lewis bases; cell lines; condensation reactions; cytotoxicity; enantiomers; flavor compounds; high performance liquid chromatography; lactones; mice; moieties; mutagens; patulin; purification methods; stereochemistry
Abstract:
... Dehydromenthofurolactone (tonkafuranone) and other bicyclic lactones are common flavour compounds and can be found in a variety of plants. Herein, we present an improved synthesis of the natural product and a series of close analogues, in combination with efficient purification methods for simple preparation from cheap and easily accessible chemicals. A two‐step, one‐pot, reaction procedure, consi ...
DOI:
10.1002/ffj.3513

34. (S)(+)-linalool from oil of coriander

Author:
Oliver, J.E.
Source:
Journal of essential oil research 2003 v.15 no.1 pp. 31-33
ISSN:
1041-2905
Subject:
chemical composition; distillates; enantiomers; Coriandrum sativum; essential oils; saponification; crystallization; linalool
DOI:
10.1080/10412905.2003.9712256

35. (S)-(+)-ipsdienol: interspecific inhibition of Ips latidens (Leconte) by Ips pini (Say) (Coleoptera: Scolytidae)

Author:
Miller, D.R.; Borden, J.H.
Source:
Journal of chemical ecology 1992 v.18 no.9 pp. 1577-1582
ISSN:
0098-0331
Subject:
enantiomers; animal communication; insect control; pheromones; Ips pini
Abstract:
... In south-central British Columbia, the attraction of Ips latidens (LeConte) to its pheromone, ipsenol, was inhibited by (S)-(+)-ipsdienol, a pheromone for I. pini (Say). (R)-(-)-ipsdienol had no effect on I. latidens. (S)-(+)-ipsdienol probably plays a role in interspecific communication between the two species, facilitating reductions in interspecific competition for breeding material and/or inte ...
DOI:
10.1007/BF00993230
PubMed:
24254288

36. (S)-2-Acetoxy-5-Undecanone, Female Sex Pheromone of the Raspberry Cane Midge, Resseliella theobaldi (Barnes)

Author:
Hall, David R.; Farman, Dudley I.; Cross, Jerry V.; Pope, Tom W.; Ando, Tetsu; Yamamoto, Masanobu
Source:
Journal of chemical ecology 2009 v.35 no.2 pp. 230-242
ISSN:
0098-0331
Subject:
Resseliella; midges; females; sex pheromones; chemical composition; antennae; electrophysiology; electroantennography; enantiomers; sex attractants; pheromone blends; trapping; pheromone traps; Rubus idaeus; raspberries; England
Abstract:
... The raspberry cane midge, Resseliella theobaldi, is a widespread pest of cultivated red raspberry in Europe. Pheromone-baited traps could provide a much-needed, accurate means to monitor the pest. Volatiles collected separately from virgin female and male midges were analyzed by gas chromatography (GC) coupled to mass spectrometry (MS) to reveal four female-specific components. In analyses by GC c ...
DOI:
10.1007/s10886-009-9588-6
PubMed:
19169750

37. (S)-BINOL-based boronic ester fluorescence sensors for enantioselective recognition of α-phenylethylamine and phenylglycinol

Author:
Jiemin Jiao; Guo Wei; Fei Li; Xuerong Mao; Yixiang Cheng; Chengjian Zhu
Source:
RSC advances 2014 v.4 no.12 pp. 5887-5892
ISSN:
2046-2069
Subject:
amines; enantiomers; enantioselectivity; fluorescence; moieties; sensors (equipment)
Abstract:
... Four chiral fluorescence sensors (S)-L1–4 incorporating boronic ester and (S)-1,1′-bi-2-naphthol (BINOL) moieties were synthesized and developed for the enantioselective recognition of α-phenylethylamine and phenylglycinol enantiomers. The sensor (S)-L1 shows an obvious fluorescence quenching “turn-off” response towards enantiomers of both α-phenylethylamine and phenylglycinol. Interestingly, the ...
DOI:
10.1039/c3ra45682j

38. (S)-Mandelic acid enolate as a chiral benzoyl anion equivalent for the enantioselective synthesis of non-symmetrically substituted benzoins

Author:
Gonzalo Blay; Isabel Fernández; Belén Monje; Marc Montesinos-Magraner; José R. Pedro
Source:
Tetrahedron 2011 v.67 no.5 pp. 881-890
ISSN:
0040-4020
Subject:
aldehydes; decarboxylation; enantiomers; ethers; hydrolysis; lithium
Abstract:
... A strategy for the enantioselective synthesis of non-symmetrically substituted benzoins from (S)-mandelic acid and aromatic aldehydes has been developed. This strategy is based on a diastereoselective aldol reaction of the lithium enolate of the 1,3-dioxolan-4-one derived from (S)-mandelic acid and pivalaldehyde with aromatic aldehydes, which gives the corresponding aldols in good yields. Subseque ...
DOI:
10.1016/j.tet.2010.12.012

39. (S)-Threonine/α,α-(S)-diphenylvalinol-derived chiral ionic liquid: an immobilized organocatalyst for asymmetric syn-aldol reactions

Author:
Natalia A. Larionova; Alexandr S. Kucherenko; Dmitry E. Siyutkin; Sergei G. Zlotin
Source:
Tetrahedron 2011 v.67 no.10 pp. 1948-1954
ISSN:
0040-4020
Subject:
aldehydes; carbon; catalysts; chemical reactions; enantiomers; heterocyclic compounds; ionic liquids; ketones
Abstract:
... Chiral ionic liquids containing (S)- or (R)-threonine amide and α,α-(S)-diphenylvalinol units were synthesized In the presence of the (S)-threonine-derived catalyst reactions between ketones with secondary carbon atom(s) at the α-position with respect to the carbonyl group and aromatic (heteroaromatic) aldehydes afforded the corresponding syn-aldols in high yields (up to 99%) and with high diaster ...
DOI:
10.1016/j.tet.2011.01.017

40. (Z)-3-nonenol, (Z,Z)-3,6-nonadienol and (S,S)-(-)-epianastrephin: male produced pheromones of the Mexican fruit fly

Author:
Robacker, David C.; Hart, William G.
Source:
Entomologia experimentalis et applicata 1985 v.39 no.2 pp. 103-108
ISSN:
0013-8703
Subject:
Anastrepha ludens; abdomen; alcohols; bioassays; enantiomers; females; fruit flies; males; pheromones
Abstract:
... (Z)-3-nonenol, (Z,Z)-3,6-nonadienol and (S,S)-(-)epianastrephin proved active as male-produced pheromones which elicited behavioral responses from virgin female Mexican fruit flies (Anastrepha ludens) (Diptera: Tephritidae) in laboratory bioassays. All three chemicals elicited attraction and/or locomotor arrest when tested individually. When tested together, (Z)-3-nonenol inhibited the behavioral ...
DOI:
10.1111/j.1570-7458.1985.tb03549.x

41. (l)- or (d)-Valine tert-butylamide grafted on permethylated β-cyclodextrin derivatives as new mixed binary chiral selectors : Versatile tools for capillary gas chromatographic enantioseparation

Author:
Stephany, O.; Dron, F.; Tisse, S.; Martinez, A.; Nuzillard, J.-M.; Peulon-Agasse, V.; Cardinaël, P.; Bouillon, J.-P.
Source:
Journal of chromatography 2009 v.1216 no.18 pp. 4051-4062
ISSN:
0021-9673
Subject:
terpenoids; enantiomers; lactones; amino acid derivatives; chromatography; beta-cyclodextrin; alcohols; siloxanes
Abstract:
... This work deals with the synthesis of two mixed binary chiral selectors prepared by grafting (l)- or (d)-valine tert-butylamide on permethylated cyclodextrin macrocycle. The enantioselective properties of the new chiral selectors diluted in OV11 polysiloxane (35% phenyl- and 65% methylsiloxane) were investigated by means of injections of 117 racemic mixtures. The mixed chiral selectors with (l)-va ...
DOI:
10.1016/j.chroma.2009.02.090

42. (±) Cochlearoids N–P: three pairs of phenolic meroterpenoids from the fungus Ganoderma cochlear and their bioactivities

Author:
Fu-Ying Qin; Yong-Ming Yan; Zheng-Chao Tu; Yong-Xian Cheng
Source:
Journal of Asian natural products research 2019 v.21 no.6 pp. 542-550
ISSN:
1477-2213
Subject:
Ganoderma; Staphylococcus aureus; cytotoxicity; enantiomers; fruiting bodies; fungi; humans; inhibitory concentration 50; meroterpenoids; neoplasm cells; spectroscopy
Abstract:
... Three pairs of meroterpenoids (±) cochlearoids N–P (1–3) were isolated from the fruiting bodies of Ganoderma cochlear. Their structures including absolute configurations were assigned by spectroscopic techniques. All the isolated compounds were tested for their inhibitory activities toward BRD4, human cancer cells, and micro-organisms. The results show that the enantiomers of (±)-1 are BRD4 inhibi ...
DOI:
10.1080/10286020.2018.1481052

43. (±) Gancochlearols A and B: cytotoxic and COX-2 inhibitory meroterpenoids from Ganoderma cochlear

Author:
Fu-Ying Qin; Yong-Ming Yan; Zheng-Chao Tu; Yong-Xian Cheng
Source:
Natural product research 2020 v.34 no.16 pp. 2269-2275
ISSN:
1478-6427
Subject:
Ganoderma; cytotoxicity; enantiomers; fruiting bodies; human cell lines; human diseases; inhibitory concentration 50; meroterpenoids; neoplasm cells; neoplasms; spectroscopy
Abstract:
... (+)- and (−)-gancochlearols A (1) and B (2), two pairs of dimeric mertoterpenoid enantiomers were isolated from the fruiting bodies of Ganoderma cochlear. Their structures were identified by spectroscopic methods. Biological assessments show that the enantiomers of 1 and 2 are cytotoxic against three human cancer cell lines (A549, K562, Huh-7) and could inhibit COX-2 expression with IC₅₀ values le ...
DOI:
10.1080/14786419.2018.1531859

44. (±)-Acortatarinowins A–F, Norlignan, Neolignan, and Lignan Enantiomers from Acorus tatarinowii

Author:
Lu Yuanyuan; Xue Yongbo; Liu Junjun; Yao Guangmin; Li Dongyan; Sun Bin; Zhang Jinwen; Liu Yanfei; Qi Changxing; Xiang Ming; Luo Zengwei; Du Guang; Zhang Yonghui
Source:
Journal of natural products 2015 v.78 no.9 pp. 2205-2214
ISSN:
1520-6025
Subject:
Acorus gramineus; X-ray diffraction; circular dichroism spectroscopy; enantiomers; high performance liquid chromatography; inhibitory concentration 50; lignans; macrophages; nitric oxide; rhizomes
Abstract:
... Three pairs of new 8-O-4′-type dinorneolignan enantiomers, (±)-acortatarinowins A–C (1a/1b–3a/3b), a pair of new 8-O-4′-type (4a/4b) and a pair of rare C7–C8′-type (5a/5b) neolignan enantiomers, (±)-acortatarinowins D and E, and a pair of new furofuran-type lignan enantiomers, (±)-acortatarinowin F (6a/6b), along with two pairs of known lignan enantiomers (7a/7b and 8a/8b), were obtained from the ...
DOI:
10.1021/acs.jnatprod.5b00328

45. (±)-Applanatumines B–D: novel dimeric meroterpenoids from Ganoderma applanatum as inhibitors of JAK3

Author:
Qi Luo; Zhen Wang; Jin-Feng Luo; Zheng-Chao Tu; Yong-Xian Cheng
Source:
RSC advances 2017 v.7 no.60 pp. 38037-38043
ISSN:
2046-2069
Subject:
Ganoderma applanatum; enantiomers; fruiting bodies; inhibitory concentration 50; spectroscopy
Abstract:
... Applanatumines B–D (1–3), three pairs of dimeric meroterpenoid enantiomers featuring the presence of a 6-oxo-4,4a,5,5a,6,8,8a,8b-octahydrofuro[3′,4′:4,5]cyclopenta[1,2-b]pyran-3-carbaldehyde structure core, were isolated from the fruiting bodies of Ganoderma applanatum. Their structures and absolute configurations were assigned by using spectroscopic methods and ECD calculations. Biological evalua ...
DOI:
10.1039/c7ra04862a

46. (±)-Aspongamide A, an N-Acetyldopamine Trimer Isolated from the Insect Aspongopus chinensis, Is an Inhibitor of p-Smad3

Author:
Yan Yong-Ming; Ai Jun; Shi Yan-Ni; Zuo Zhi-Li; Hou Bo; Luo Jie; Cheng Yong-Xian
Source:
Organic letters 2014 v.16 no.2 pp. 532-535
ISSN:
1523-7052
Subject:
Aspongopus; enantiomers; extracellular matrix; insects; organic compounds; phosphorylation; rats; spectroscopy; transforming growth factor beta 1
Abstract:
... (±)-Aspongamide A (1), an unusual trimer of N-acetyldopamine (NADA) bearing a novel tetrahydrobenzo[a]dibenzo[b,e][1,4]dioxine structure, and a pair of NADA dimeric enantiomers (2) were isolated from Aspongopus chinensis. The structures of compounds 1 and 2 were assigned using spectroscopic methods. Compound 1 was found to be an inhibitor of Smad3 phosphorylation in transforming growth factor-β1 ( ...
DOI:
10.1021/ol403409v

47. (±)-Bicoryanhunine A, dimeric benzylisoquinoline alkaloid atropo-enantiomers from Corydalis yanhusuo

Author:
Biao-Bing Xiao; Gui-Yang Xia; Ling-Yan Wang; Bo-Lin Qiu; Huan Xia; Wan-Chao Zhong; Gui-Hua Tian; Sheng Lin
Source:
Tetrahedron letters 2020 v.61 no.21 pp. 151890
ISSN:
0040-4039
Subject:
Corydalis yanhusuo; alkaloids; chemical reactions; enantiomers; high performance liquid chromatography; inhibitory concentration 50; spectroscopy; tubers
Abstract:
... Bicoryanhunine A (1), isolated from the dried tubers of Corydalis yanhusuo, is the first novel dimeric benzylisoquinoline alkaloid with a 4,7′-coupled biaryl axis. This novel C-4-C-7′ linkage lead to the highest steric hindrance at the biaryl axis, giving rise to a pair of atropo-enantiomers that are well resolved into the anticipated enantiomers, (+)-bicoryanhunine A (1) and (−)-bicoryanhunine A ...
DOI:
10.1016/j.tetlet.2020.151890

48. (±)-Evodiakine, A Pair of Rearranged Rutaecarpine-Type Alkaloids From Evodia rutaecarpa

Author:
Yan-Hong Li; Yu Zhang; Li-Yan Peng; Xiao-Nian Li; Qin-Shi Zhao; Rong-Tao Li; Xing-De Wu
Source:
Nat. Prod. Bioprospect. 2016 v.6 no.6 pp. 291-296
ISSN:
2192-2195
Subject:
Euodia; X-ray diffraction; alkaloids; anti-inflammatory activity; circular dichroism spectroscopy; cytotoxicity; enantiomers; fruits; high performance liquid chromatography; mass spectrometry; nuclear magnetic resonance spectroscopy
Abstract:
... (±)-Evodiakine (1a and 1b), a pair of rearranged rutaecarpine-type alkaloids with an unprecedented 6/5/5/7/6 ring system, were isolated from the nearly ripe fruits of Evodia rutaecarpa. Separation of the enantiomers have been achieved by chiral HPLC column. The structures of (±)-evodiakine were unambiguously elucidated by 1D and 2D NMR spectra, mass spectrometry, and single-crystal X-ray diffracti ...
DOI:
10.1007/s13659-016-0113-7
PubMed:
27873184
PubMed Central:
PMC5136374

49. (±)-Ganoapplanin, a Pair of Polycyclic Meroterpenoid Enantiomers from Ganoderma applanatum

Author:
Li Lei; Li Huan; Peng Xing-Rong; Hou Bo; Yu Mu-Yuan; Dong Jin-Run; Li Xiao-Nian; Zhou Lin; Yang Jian; Qiu Ming-Hua
Source:
Organic letters 2016 v.18 no.23 pp. 6078-6081
ISSN:
1523-7052
Subject:
Ganoderma applanatum; X-ray diffraction; calcium channels; chemical reactions; circular dichroism spectroscopy; enantiomers; organic compounds; spectral analysis
Abstract:
... (±)-Ganoapplanin (1), a pair of novel meroterpenoid enantiomers featuring an unprecedented dioxaspirocyclic skeleton constructed from a 6/6/6/6 tetracyclic system and an unusual tricyclo[4.3.3.0³′,⁷′]dodecane motif, were isolated from Ganoderma applanatum. Its structure and absolute configurations were determined by spectroscopic analyses, X-ray crystallography, and ECD (electronic circular dichro ...
DOI:
10.1021/acs.orglett.6b03064

50. (±)-Homocrepidine A, a Pair of Anti-inflammatory Enantiomeric Octahydroindolizine Alkaloid Dimers from Dendrobium crepidatum

Author:
Hu Yang; Zhang Chaofeng; Zhao Xin; Wang Yue; Feng Deqiang; Zhang Mian; Xie Haifeng
Source:
Journal of natural products 2016 v.79 no.1 pp. 252-256
ISSN:
1520-6025
Subject:
Dendrobium; X-ray diffraction; alkaloids; anti-inflammatory activity; enantiomers; high performance liquid chromatography; inducible nitric oxide synthase; inhibitory concentration 50; macrophages; nitric oxide; piperidines
Abstract:
... A pair of racemic indolizidine enantiomers, (±)-homocrepidine A (1), and a piperidine derivative, homocrepidine B (2), were isolated from Dendrobium crepidatum along with the known alkaloid crepidine (3). The racemic mixture of 1 was separated into a pair of enantiomers, (+)-1 and (−)-1, by HPLC using a chiral chromatographic substrate, which represents the first successful example of resolving in ...
DOI:
10.1021/acs.jnatprod.5b00801

51. (±)-Japonicols A–D, Acylphloroglucinol-Based Meroterpenoid Enantiomers with Anti-KSHV Activities from Hypericum japonicum

Author:
Hu Linzhen; Xue Yongbo; Zhang Jinwen; Zhu Hucheng; Chen Chunmei; Li Xiao-Nian; Liu Junjun; Wang Zhenzhen; Zhang Yu; Zhang Yonghui
Source:
Journal of natural products 2016 v.79 no.5 pp. 1322-1328
ISSN:
1520-6025
Subject:
Hypericum; X-ray diffraction; circular dichroism spectroscopy; enantiomers; median effective concentration; terpenoids
Abstract:
... (±)-Japonicols A–D (1a/1b–4a/4b), four pairs of new phloroglucinol-based terpenoid enantiomers, were isolated from Hypericum japonicum. Their absolute configurations were confirmed through comparison of their experimental and calculated electronic circular dichroism spectra and single-crystal X-ray diffraction analyses. Compounds 1a/1b, 2a/2b, and 3a/3b possess 2-oxabicyclo[3.3.1]nonane, pyrano[3, ...
DOI:
10.1021/acs.jnatprod.5b01119

52. (±)-Melicolones A and B, Rearranged Prenylated Acetophenone Stereoisomers with an Unusual 9-Oxatricyclo[3.2.1.13,8]nonane Core from the Leaves of Melicope ptelefolia

Author:
Xu Jin-Fang; Zhao Hui-Jun; Wang Xiao-Bing; Li Zhong-Rui; Luo Jun; Yang Ming-Hua; Yang Lei; Yu Wen-Ying; Yao He-Quan; Luo Jian-Guang; Kong Ling-Yi
Source:
Organic letters 2015 v.17 no.1 pp. 146-149
ISSN:
1523-7052
Subject:
Melicope; chemical reactions; enantiomers; endothelial cells; high performance liquid chromatography; humans; leaves; organic compounds; oxidative stress; spectral analysis
Abstract:
... Melicolones A (1) and B (2), a pair of rearranged prenylated acetophenone epimers with an unusual 9-oxatricyclo[3.2.1.1³,⁸]nonane core, were isolated from the leaves of Melicope ptelefolia. Further chiral high-performance liquid chromatography resolution gave enantiomers (+)- and (−)-1, as well as (+)- and (−)-2, respectively. The structures and absolute configurations of the pure enantiomers were ...
DOI:
10.1021/ol5033738

53. (±)-Paeoveitol, a Pair of New Norditerpene Enantiomers from Paeonia veitchii

Author:
Liang Wen-Juan; Geng Chang-An; Zhang Xue-Mei; Chen Hao; Yang Cai-Yan; Rong Guang-Qing; Zhao Yong; Xu Hong-Bo; Wang Hao; Zhou Ning-Jia; Ma Yun-Bao; Huang Xiao-Yan; Chen Ji-Jun
Source:
Organic letters 2014 v.16 no.2 pp. 424-427
ISSN:
1523-7052
Subject:
Paeonia; X-ray diffraction; biogenesis; chemical reactions; circular dichroism spectroscopy; enantiomers; nuclear magnetic resonance spectroscopy; organic compounds
Abstract:
... (+)-Paeoveitol and (−)-paeoveitol, a pair of new norditerpene enantiomers, were isolated from the root of Paeonia veitchii. Their structures and absolute configurations were determined on the basis of extensive analysis of 1D and 2D NMR spectra, crystal X-ray diffraction, and electronic circular dichroism (ECD). A possible biogenesis involving two molecules of paeoniflorin was postulated. ...
DOI:
10.1021/ol403315d

54. (±)-Quassidine K, a pair of cytotoxic bis-β-carboline alkaloid enantiomers from Picrasma quassioides

Author:
Xin-Ming Guo; Fei Li; Fang-Fang Zheng; Na-Na Gong; Yan Li; Wen-Zhou Feng; Lin Tian
Source:
Natural product research 2020 v.34 no.4 pp. 489-493
ISSN:
1478-6427
Subject:
Picrasma quassioides; alkaloids; cytotoxicity; enantiomers; human cell lines; inhibitory concentration 50; spectral analysis
Abstract:
... (±)-Quassidine K (1), a pair of new bis-β-carboline alkaloid enantiomers, were isolated from Picrasma quassioides. Their structures were determined on the basis of detailed spectroscopic data analysis. The absolute configurations of (+)-S-quassidine K (1a) and (−)-R-quassidine K (1b) were determined by comparing with the reported experimental ECD spectra after chiral separation. The cytotoxicity a ...
DOI:
10.1080/14786419.2018.1489388

55. (±)-Quassidines I and J, Two Pairs of Cytotoxic Bis-β-carboline Alkaloid Enantiomers from Picrasma quassioides

Author:
Jiao Wei-Hua; Chen Guo-Dong; Gao Hao; Li Jing; Gu Bin-Bin; Xu Ting-Ting; Yu Hao-Bing; Shi Guo-Hua; Yang Fan; Yao Xin-Sheng; Lin Hou-Wen
Source:
Journal of natural products 2015 v.78 no.1 pp. 125-130
ISSN:
1520-6025
Subject:
Picrasma quassioides; X-ray diffraction; alkaloids; cytotoxicity; enantiomers; high performance liquid chromatography; humans; inhibitory concentration 50; melanoma; mice; nuclear magnetic resonance spectroscopy; spectral analysis; stems
Abstract:
... (±)-Quassidines I (1) and J (2), two pairs of new bis-β-carboline alkaloid enantiomers, were isolated from the stems of Picrasma quassioides. Their structures were determined by the analysis of spectroscopic data, including HRESIMS and 2D NMR, and confirmed by single-crystal X-ray diffraction analysis. The racemic mixtures of 1 and 2 were resolved into two pairs of enantiomers, (+)-S-1a and (−)-R- ...
DOI:
10.1021/np500801s

56. (±)-Sativamides A and B, Two Pairs of Racemic Nor-Lignanamide Enantiomers from the Fruits of Cannabis sativa

Author:
Guo-Yuan Zhu; Ji Yang; Xiao-Jun Yao; Xing Yang; Jing Fu; Xin Liu; Li-Ping Bai; Liang Liu; Zhi-Hong Jiang
Source:
Journal of organic chemistry 2018 v.83 no.4 pp. 2376-2381
ISSN:
1520-6904
Subject:
Cannabis sativa; chemical reactions; cytotoxicity; enantiomers; endoplasmic reticulum; fruits; hemp; high performance liquid chromatography; organic chemistry; organic compounds; spectral analysis
Abstract:
... (±)-Sativamides A (1) and B (2), two pairs of nor-lignanamide enantiomers featuring a unique benzo-angular triquinane skeleton, were isolated from the fruits of Cannabis sativa (hemp seed). Their structures were elucidated by detailed spectroscopic analysis and ECD calculations. The resolution of (+)- and (−)-sativamides A and B were achieved by chiral HPLC. Pretreatment of neuroblastoma cells wit ...
DOI:
10.1021/acs.joc.7b02765

57. (±)-Stagonosporopsin A, stagonosporopsin B and stagonosporopsin C, antibacterial metabolites produced by endophytic fungus Stagonosporopsis oculihominis

Author:
Ju-Tao Wang; Hui-Yuan Li; Rao Rao; Jing-Yi Yue; Guo-Kai Wang; Yang Yu
Source:
Phytochemistry letters 2021 v.45 pp. 157-160
ISSN:
1874-3900
Subject:
Dendrobium catenatum; Stagonosporopsis; X-ray diffraction; circular dichroism spectroscopy; enantiomers; endophytes; fungi; plant biochemistry; secondary metabolites
Abstract:
... A successive investigation of the endophytic fungus Stagonosporopsis oculihominis isolated from Dendrobium huoshanense led to the discovery of two undescribed secondary metabolites, (±)-stagonosporopsin A and stagonosporopsin B, and a new natural product, stagonosporopsin C. (±)-stagonosporopsin A is a pair of enantiomer. The structures of the isolated compounds, including their absolute configura ...
DOI:
10.1016/j.phytol.2021.08.017

58. (±)-Torreyunlignans A–D, Rare 8–9′ Linked Neolignan Enantiomers as Phosphodiesterase-9A Inhibitors from Torreya yunnanensis

Author:
Cheng Zhong-Bin; Lu Xiao; Bao Jing-Mei; Han Qing-Hua; Dong Zhen; Tang Gui-Hua; Gan Li-She; Luo Hai-Bin; Yin Sheng
Source:
Journal of natural products 2014 v.77 no.12 pp. 2651-2657
ISSN:
1520-6025
Subject:
Alzheimer disease; Torreya; adenosine; diabetes; enantiomers; inhibitory concentration 50; lignans; spectroscopy; tritium
Abstract:
... (±)-Torreyunlignans A–D (1a/1b–4a/4b), four pairs of new 8–9′ linked neolignan enantiomers featuring a rare (E)-2-styryl-1,3-dioxane moiety, were isolated from the trunk of Torreya yunnanensis. The structures were determined by combined spectroscopic and chemical methods, and the absolute configurations were elucidated by ECD calculations. The compounds were screened by using tritium-labeled adeno ...
DOI:
10.1021/np500528u

59. (±)-Tylopilusins, Diphenolic Metabolites from the Fruiting Bodies of Tylopilus eximius

Author:
Fukuda Takashi; Nagai Kenichiro; Tomoda Hiroshi
Source:
Journal of natural products 2012 v.75 no.12 pp. 2228-2231
ISSN:
1520-6025
Subject:
Tylopilus; X-ray diffraction; circular dichroism spectroscopy; enantiomers; fruiting bodies; metabolites; nuclear magnetic resonance spectroscopy; spectral analysis
Abstract:
... Racemates of the diphenolic metabolites (±)-tylopilusin A (1) and (±)-tylopilusin B (2) were isolated from the fruiting bodies of Tylopilus eximius. Their structures were elucidated on the basis of spectroscopic analyses (1D and 2D NMR data and ROESY correlations) and X-ray crystallography. Each racemate was separated into its individual enantiomers, and electronic circular dichroism calculations ...
DOI:
10.1021/np300428r

60. (±)-Ulodione A, a pair of unprecedented cyclopentanones from Ulospora bilgramii

Author:
Xiao-Yi Luan; Fei Xie; Ke Xu; Yun Gao; Jing-Hui Lu; Hong-Xiang Lou
Source:
Tetrahedron letters 2020 v.61 no.15 pp. 151732
ISSN:
0040-4039
Subject:
X-ray diffraction; biochemical pathways; chemical reactions; cholinesterase; circular dichroism spectroscopy; electrospray ionization mass spectrometry; enantiomers; fungi; high performance liquid chromatography; inhibitory concentration 50; metabolites; nuclear magnetic resonance spectroscopy; organic compounds
Abstract:
... Two novel enantiomers named (R)-ulodione A (1a) and (S)-ulodione A (1b) possessing a new 5/6–5 spiro skeleton and a related metabolite ulodione B (2) were isolated from the endolichenic fungus Ulospora bilgramii. Enantiomeric separation was achieved by HPLC on a chiral column. The structures and absolute configurations of ulodione A were elucidated by means of 1D and 2D NMR spectra, high-resolutio ...
DOI:
10.1016/j.tetlet.2020.151732

61. (±)-Uncarilins A and B, Dimeric Isoechinulin-Type Alkaloids from Uncaria rhynchophylla

Author:
Geng Chang-An; Huang Xiao-Yan; Ma Yun-Bao; Hou Bo; Li Tian-Ze; Zhang Xue-Mei; Chen Ji-Jun
Source:
Journal of natural products 2017 v.80 no.4 pp. 959-964
ISSN:
1520-6025
Subject:
Uncaria rhynchophylla; X-ray diffraction; alkaloids; enantiomers; nuclear magnetic resonance spectroscopy; receptors; spectral analysis
Abstract:
... (±)-Uncarilins A and B (1a/1b and 2a/2b), two pairs of unusual dimeric isoechinulin-type enantiomers with a symmetric four-membered core, were isolated from Uncaria rhynchophylla driven by LCMS-IT-TOF analyses. Their structures were elucidated by extensive 1D and 2D NMR spectra, X-ray diffraction, and ECD spectroscopic data. (−)-Uncarilin B (2a) showed activities on MT₁ and MT₂ receptors with agon ...
DOI:
10.1021/acs.jnatprod.6b00938

62. (±)-Xylaridines A and B, Highly Conjugated Alkaloids from the Fungus Xylaria longipes

Author:
Jing Li; Wen-Xuan Wang; He-Ping Chen; Zheng-Hui Li; Juan He; Yong-Sheng Zheng; Huan Sun; Rong Huang; Qing-Xia Yuan; Xian Wang; Tao Feng; Ji-Kai Liu
Source:
Organic letters 2019 v.21 no.5 pp. 1511-1514
ISSN:
1523-7052
Subject:
X-ray diffraction; Xylaria; alkaloids; biosynthesis; chemical reactions; enantiomers; fungi; spectral analysis
Abstract:
... Two highly conjugated alkaloids xylaridines A (1) and B (2) were obtained as racemates from the fungus Xylaria longipes. They were resoluted into optically pure enantiomers, respectively. Their structures were determined by extensive spectroscopic analyses, X-ray diffraction, and equivalent circulating density (ECD) calculations. Compound 1 possesses a 5/6/6/5/5 fused ring system with unique 2-aza ...
DOI:
10.1021/acs.orglett.9b00312

63. (−) and (+)-Merrilliaquinone, a pair of new quinone enantiomers from Illicium merrillianum and their distinctive effect on human hepatoma and hepatic cells

Author:
Xinhui Tian; Li Li; Jinpeng Pei; Rongcai Yue; Xin Fang; Jianping Zhang; Weiwei He; Lei Shan; Yunheng Shen; Weidong Zhang
Source:
RSC advances 2015 v.5 no.93 pp. 75857-75862
ISSN:
2046-2069
Subject:
Illicium; apoptosis; cell cycle checkpoints; cytotoxicity; enantiomers; flow cytometry; hepatoma; inhibitory concentration 50; interphase; membrane potential; mitochondrial membrane; quantum mechanics; quinones; spectral analysis
Abstract:
... Merrilliaquinone (1), a new racemic quinone was isolated from the branches and leaves of Illicium merrillianum. Chiral separation of 1 gave two enantiomers (−)-merrilliaquinone (1a) and (+)-merrilliaquinone (1b). The structure of 1 was established by comprehensive spectroscopic analysis, and the absolute configurations of 1a and 1b were determined by quantum mechanical calculation of ECD spectra. ...
DOI:
10.1039/c5ra15074d

64. 1,1′-Methylene-bis(1,1′,2,2′,3,3′,4,4′-octahydroisoquinoline): synthesis, reaction, resolution, and application in catalytic enantioselective transformations

Author:
Qiong Ji Yao; Zaher M.A. Judeh
Source:
Tetrahedron 2011 v.67 no.22 pp. 4086-4092
ISSN:
0040-4020
Subject:
X-ray diffraction; bromine; chemical reactions; copper; enantiomers; organic compounds
Abstract:
... The preparation of new chiral 1,3-diamine ligand systems based on the 1,1′-methylene-bis(1,1′,2,2′,3,3′,4,4′-octahydroisoquinoline) framework is described. Synthesis of various mono-, di-, and bridged N-alkyl derivatives are presented. Resolution of one compound, its Cu(I)Br X-ray crystallographic structure and the preliminary results on its application in the enantioselective Henry and Aldol reac ...
DOI:
10.1016/j.tet.2011.04.004

65. 1,2,3- versus 1,2-Indeno Ring Fusions Influence Structure Property and Chirality of Corannulene Bowls

Author:
Shi Liu; Loïc M. Roch; Oliver Allemann; Jun Xu; Nicolas Vanthuyne; Kim K. Baldridge; Jay S. Siegel
Source:
Journal of organic chemistry 2018 v.83 no.7 pp. 3979-3986
ISSN:
1520-6904
Subject:
catalytic activity; crystal structure; enantiomers; optical isomerism; organic chemistry; organic compounds
Abstract:
... Annulated corannulenes 3–5 form via distinct synthetic pathways: (i) Pd-catalyzed sp³ CH insertion, (ii) Pd-catalyzed aryl coupling, and (iii) silyl cation-promoted C–F activation/CH insertion. Crystal structure, redox, and photophysical studies elucidate the differing influence of 1,2,3- versus 1,2-indeno ring fusions. Mono and dianions of 3–5 are characterized. Resolution of 4 gives enantiopure ...
DOI:
10.1021/acs.joc.8b00320

66. 1,3-Dipolar Cycloaddition of 2,6-Dichlorobenzonitrile Oxide to 2-Methyl-N-confused Porphyrin. Regio- and Stereoselective Synthesis and Structural Characterization of 2-Aza-21-carbabacteriochlorin and Resolution of 2-Aza-21-carbachlorin Enantiomers

Author:
Li Xiaofang; Liu Bin; Yu Xianyong; Yi Pinggui; Yi Rongqiong; Chmielewski Piotr J.
Source:
Journal of organic chemistry 2012 v.77 no.5 pp. 2431-2440
ISSN:
1520-6904
Subject:
X-ray diffraction; crystal structure; cycloaddition reactions; enantiomers; organic chemistry; porphyrins; stereoselective synthesis
Abstract:
... The 1,3-dipolar cycloaddition reaction of 2-methyl-N-confused porphyrin with 2,6-dichlorobenzonitrile oxide yielded four isomeric monoadducts of carbachlorin type and one diadduct of carbabacteriochlorin type. Two major carbachlorin products, constituting 82% of the monoadducts, were shown to be structural precursors of the unique 2-aza-21-carbabacteriochlorin. Enantiomers of the most abundant iso ...
DOI:
10.1021/jo3000817

67. 1,4-Phenylene-Incorporated Decaphyrin(1.0.1.0.0.1.0.1.0.0): Synthesis, Structure, and Topological Chirality

Author:
Yunchao Zheng; Xue Wang; Hao Chen; Tian Lu; Zhiming Duan; Chuanhu Lei
Source:
Organic letters 2022 v.24 no.13 pp. 2509-2514
ISSN:
1523-7052
Subject:
absorption; circular dichroism spectroscopy; enantiomers; optical isomerism; topology
Abstract:
... Expanded porphyrins represent emerging structures in realizing topological chirality; however, their inherent flexibility has hampered the effective chiral resolution. Herein, we rationally designed a decaphyrin 9, which could be separated into its enantiomers in the free-base form. The enantiomers showed noteworthy chiroptical properties, e.g., the intense circular dichroism response in the visib ...
DOI:
10.1021/acs.orglett.2c00636

68. 1,5-Rhodium Shift in Rearrangement of N-Arenesulfonylazetidin-3-ols into Benzosultams

Author:
Ishida Naoki; Shimamoto Yasuhiro; Yano Takaaki; Murakami Masahiro
Source:
Journal of the American Chemical Society 2013 v.135 no.51 pp. 19103-19106
ISSN:
1520-5126
Subject:
amino acids; chemical bonding; enantiomers
Abstract:
... Benzosultams are synthesized in an enantiopure form starting from α-amino acids through a rhodium-catalyzed rearrangement reaction of N-arenesulfonylazetidin-3-ols. Mechanistically, this reaction involves C–C bond cleavage by β-carbon elimination and C–H bond cleavage by a 1,5-rhodium shift. ...
DOI:
10.1021/ja410910s

69. 1-, 2- and 3-AG as substrates of the endocannabinoid enzymes and endogenous ligands of the cannabinoid receptor 1

Author:
Shrouq I. Farah; Samantha Hilston; Ngan Tran; Nikolai Zvonok; Alexandros Makriyannis
Source:
Biochemical and biophysical research communications 2022 v.591 pp. 31-36
ISSN:
0006-291X
Subject:
acylglycerol lipase; agonists; amide hydrolases; cannabinoid receptors; cannabinoids; enantiomers; fatty acids; hydrolysis; isomerization; ligands; monoacylglycerols; research; serine; stereochemistry
Abstract:
... 2-Arachidonoylglycerol (2-AG) is the most potent and abundant endocannabinoid that acts as a full agonist at the cannabinoid 1 (CB1) and 2 (CB2) receptors. It serves as a substrate for several serine hydrolases, including monoacylglycerol lipase (MGL), α/β hydrolase domain 6 (ABHD6) and fatty acid amide hydrolase (FAAH). However, 2-AG's rapid conversion to 1-AG (the S stereoisomer) and 3-AG (the R ...
DOI:
10.1016/j.bbrc.2021.12.105

70. 1-Methyl-1,2,3,4-tetrahydro-beta-carboline-3-carboxylic acid and 1,2,3,4-tetrahydro-beta-carboline-3-carboxylic acid in fruits

Author:
Herraiz, T.
Source:
Journal of agricultural and food chemistry 1999 v.47 no.12 pp. 4883-4887
ISSN:
0021-8561
Subject:
tomatoes; chemical composition; enantiomers; indoles; ripening; storage
Abstract:
... 1,2,3,4-Tetrahydro-beta-carboline-3-carboxylic acid (THCA) and 1-methyl-1,2,3,4-tetrahydro-beta-carboline -3-carboxylic acid (MTCA), as two diastereoisomers (1S,3S and 1R,3S), occurred in commercial fruits. Citrus fruits exhibited the highest content; other fruits contained very low levels or none at all. The content of MTCA was as follows: orange, 0.35-2.47 micrograms/g; lemon, 0.15-2.05 microgra ...
DOI:
10.1021/jf990233d
PubMed:
10606547

71. 11-Step Total Synthesis of (−)-Maoecrystal V

Author:
Cernijenko Artiom; Risgaard Rune; Baran Phil S.
Source:
Journal of the American Chemical Society 2016 v.138 no.30 pp. 9425-9428
ISSN:
1520-5126
Subject:
bioactive properties; biosynthesis; diterpenoids; enantiomers
Abstract:
... An expedient, practical, and enantioselective route to the highly congested ent-kaurane diterpene maoecrystal V is presented. This route, which has been several years in the making, is loosely modeled after a key pinacol shift in the proposed biosynthesis. Only 11 steps, many of which are strategic in that they build key skeletal bonds and incorporate critical functionalities, are required to acce ...
DOI:
10.1021/jacs.6b06623
PubMed:
27457680
PubMed Central:
PMC4974602

72. 12-Hydroxyjasmonic Acid Glucoside Is a COI1-JAZ-Independent Activator of Leaf-Closing Movement in Samanea saman

Author:
Nakamura, Yoko; Mithöfer, Axel; Kombrink, Erich; Boland, Wilhelm; Hamamoto, Shin; Uozumi, Nobuyuki; Tohma, Kentaro; Ueda, Minoru
Source:
Plant physiology 2011 v.155 no.3 pp. 1226-1236
ISSN:
0032-0889
Subject:
Arabidopsis thaliana; Phaseolus lunatus; Samanea saman; bioassays; enantiomers; gene induction; jasmonic acid; leaves; lima beans; plant growth substances; potassium; protoplasts; shrinkage; stress response; volatile organic compounds
Abstract:
... Jasmonates are ubiquitously occurring plant growth regulators with high structural diversity that mediate numerous developmental processes and stress responses. We have recently identified 12-O-β-D-glucopyranosyljasmonic acid as the bioactive metabolite, leaf-closing factor (LCF), which induced nyctinastic leaf closure of Samanea saman. We demonstrate that leaf closure of isolated Samanea pinnae i ...
DOI:
10.1104/pp.110.168617
PubMed:
21228101
PubMed Central:
PMC3046581

73. 12/10-Helical β-Peptide with Dynamic Folding Propensity: Coexistence of Right- and Left-Handed Helices in an Enantiomeric Foldamer

Author:
Shin Seonho; Lee Mihye; Guzei Ilia A.; Kang Young Kee; Choi Soo Hyuk
Source:
Journal of the American Chemical Society 2016 v.138 no.40 pp. 13390-13395
ISSN:
1520-5126
Subject:
crystal structure; enantiomers; peptides; protein folding; protein secondary structure; stereoisomerism; temperature
Abstract:
... We present the first examples of atomic-resolution crystal data for the β-peptide 12/10-helix from oligomers of cis-2-aminocyclohexane carboxylic acid (cis-ACHC) with alternating chirality. The local conformations of two enantiomeric cis-ACHC dimer units suggested that a chiral β-peptide may adopt both right-handed and left-handed helical conformations in solution. To probe the conformational beha ...
DOI:
10.1021/jacs.6b08235

74. 13,13a-seco-protoberberines from the tubers of Corydalis yanhusuo and their anti-inflammatory activity

Author:
Gui-Yang Xia; Dong-Jie Fang; Ling-Yan Wang; Huan Xia; Ya-Nan Wang; Hong-Cai Shang; Sheng Lin
Source:
Phytochemistry 2022 v.194 pp. 113023
ISSN:
0031-9422
Subject:
Corydalis yanhusuo; Western blotting; active sites; anti-inflammatory activity; bioassays; enantiomers; inducible nitric oxide synthase; interleukin-6; lipopolysaccharides; molecular dynamics; nitric oxide; plant biochemistry; skeleton; spectral analysis; transcription factor NF-kappa B
Abstract:
... Six undescribed protoberberine derivatives including two pairs of enantiomers, named yanhusanines G-L, along with fifteen reported protoberberine alkaloids, were isolated from the tubers of Corydalis yanhusuo. Among them, yanhusanines H-L feature a unique 13,13a-seco skeleton which is rare in nature. Their structural elucidations were achieved by extensive spectroscopic analysis and quantum chemis ...
DOI:
10.1016/j.phytochem.2021.113023

75. 13C NMR Spectroscopy for the Differentiation of Enantiomers Using Chiral Solvating Agents

Author:
Pérez-Trujillo Míriam; Monteagudo Eva; Parella Teodor
Source:
Analytical chemistry 2013 v.85 no.22 pp. 10887-10894
ISSN:
1520-6882
Subject:
drugs; enantiomers; metabolites; metabolomics; nuclear magnetic resonance spectroscopy; stable isotopes
Abstract:
... The utility of ¹³C NMR spectroscopy for the differentiation of enantiomers using chiral solvating agents (CSA) is stated. Three examples involving the enantiodifferentiation of a drug, a metabolite and a reactant in aqueous and organic solutions have been chosen to show it. The intrinsic high dispersion of ¹³C nucleus, as well as the singlet nature of the signals in standard experiments makes ¹³C ...
DOI:
10.1021/ac402580j

76. 17-Hydroxybrevianamide N and Its N1-Methyl Derivative, Quinazolinones from a Soft-Coral-Derived Aspergillus sp. Fungus: 13S Enantiomers as the True Natural Products

Author:
Wei-Feng Xu; Rong Chao; Yang Hai; Yang-Yang Guo; Mei-Yan Wei; Chang-Yun Wang; Chang-Lun Shao
Source:
Journal of natural products 2021 v.84 no.4 pp. 1353-1358
ISSN:
1520-6025
Subject:
Aspergillus; X-ray diffraction; alkaloids; enantiomers; ethyl acetate; fungi; spectral analysis
Abstract:
... Under the guidance of MS/MS-based molecular networking and HPLC-UV, two new alkaloid racemates, (±)-17-hydroxybrevianamide N (1) and (±)-N1-methyl-17-hydroxybrevianamide N (2), featuring a rare o-hydroxyphenylalanine residue and an imide subunit, were isolated from a soft-coral-derived Aspergillus sp. fungus. The true natural products (+)-1 and (+)-2 were further monitored and obtained from the fr ...
DOI:
10.1021/acs.jnatprod.1c00098

77. 17α-Estradiol, an ignored endogenous natural estrogen in human: Updated estrogen metabolism pathways and its environmental risk analysis

Author:
Zhao Tang; Ze-hua Liu; Hao Wang; Zhi Dang
Source:
Science of the total environment 2022 v.829 pp. 154693
ISSN:
0048-9697
Subject:
enantiomers; environment; estrogenic properties; estrogens; humans; metabolism; municipal wastewater; risk; risk analysis; surface water; urine
Abstract:
... E1 and E2 are considered as the parent natural estrogens (NEs) in human metabolism pathways of NEs, while the enantiomer of E2, αE2 was not included and ignored. In this study, αE2 along with the other eleven NEs with estrogenic activities were found in six healthy human urines with the total concentration levels of 62.9–99.3 μg/L. The concentration contributed ratios (CCRs) of αE2 to the total tw ...
DOI:
10.1016/j.scitotenv.2022.154693

78. 1H NMR analyses of enantiomeric mixtures using chiral liquid crystals

Author:
Jonathan Farjon; Nicolas Giraud
Source:
Current opinion in colloid & interface science 2018 v.33 pp. 1-8
ISSN:
1359-0294
Subject:
anisotropy; enantiomers; liquid crystals; nuclear magnetic resonance spectroscopy; rapid methods; solutes
Abstract:
... Nuclear Magnetic Resonance in chiral liquid crystalline media is a powerful tool for deciphering mixtures of enantiomers. ¹H NMR appears to be the most sensitive technique for analyzing enantiomers but remains very challenging for the analysis of chiral solutes interacting with weakly orienting media. Indeed, probing ¹H networks even for small sized molecules is difficult because in oriented media ...
DOI:
10.1016/j.cocis.2017.11.001

79. 1H NMR spectroscopy in the presence of Mosher acid to rapidly determine the enantiomeric composition of amino acid benzyl esters, chirons susceptible to easy racemization

Author:
Cristiano Bolchi; Gabriella Roda; Marco Pallavicini
Source:
Amino acids 2018 v.50 no.12 pp. 1759-1767
ISSN:
0939-4451
Subject:
amino acids; carbon; enantiomers; esters; high performance liquid chromatography; nuclear magnetic resonance spectroscopy; protons; solvents
Abstract:
... Amino acid benzyl esters are very useful chiral synthons, whose enantiomeric purity needs to be carefully verified because of their susceptibility to easy racemization. Alternative to chiral HPLC, ¹H NMR in the presence of a chiral solvating agent (CSA) can allow a more rapid and acceptably accurate determination of the enantiomeric composition, if explicit spectral non-equivalence of one or more ...
DOI:
10.1007/s00726-018-2653-0

80. 1H NMR-based metabolomics analysis of adult zebrafish (Danio rerio) after exposure to diniconazole as well as its bioaccumulation behavior

Author:
Yao Wang; Wentao Zhu; Dezhen Wang; Miaomiao Teng; Jin Yan; Jiyan Miao; Zhiqiang Zhou
Source:
Chemosphere 2017 v.168 pp. 1571-1577
ISSN:
0045-6535
Subject:
Danio rerio; adults; alanine; amino acid metabolism; aquatic organisms; bioaccumulation; choline; creatine; diniconazole; enantiomers; energy metabolism; environmental assessment; glucose; histology; isoleucine; lactic acid; leucine; lipid metabolism; liver; metabolomics; spermatids; taurine; triazoles; valine
Abstract:
... As a systemic triazole fungicide, limited information is known about diniconazole. In this study, toxicological effects and bioaccumulation behavior of diniconazole in zebrafish were both evaluated to perform an overall assessment of its environmental risk towards aquatic organisms. The 1H NMR-based metabolomics analysis revealed that 70 μg L−1 diniconazole exposure increased valine, leucine, isol ...
DOI:
10.1016/j.chemosphere.2016.11.157

81. 2,2,2-Trichloroethyl Aryldiazoacetates as Robust Reagents for the Enantioselective C–H Functionalization of Methyl Ethers

Author:
Guptill David M.; Davies Huw M. L.
Source:
Journal of the American Chemical Society 2014 v.136 no.51 pp. 17718-17721
ISSN:
1520-5126
Subject:
catalysts; enantiomers; ethers; rhodium
Abstract:
... A new class of reagents is described for C–H functionalization by means of C–H insertion using donor/acceptor-substituted rhodium(II) carbene intermediates. The 2,2,2-trichloroethyl aryl and heteroaryl diazoacetates, together with the dirhodium triarylcyclopropane carboxylate catalyst Rh₂(R-BPCP)₄, enabled the enantioselective intermolecular C–H functionalization of a range of methyl ethers with h ...
DOI:
10.1021/ja5107404

82. 2,2′-Bipyridine-α,α′-trifluoromethyl-diol ligand: synthesis and application in the asymmetric Et₂Zn alkylation of aldehydes

Author:
Samuel Lauzon; Thierry Ollevier
Source:
Chemical communications 2021 v.57 no.84 pp. 11025-11028
ISSN:
1364-548X
Subject:
enantiomers; ethylation; heterocyclic compounds; ligands
Abstract:
... A chiral 2,2′-bipyridine ligand (1) bearing α,α′-trifluoromethyl-alcohols at 6,6′-positions was designed in five steps affording either the R,R or S,S enantiomer with excellent stereoselectivities, i.e. 97% de, >99% ee and >99.5% de, >99.5% ee, respectively. The key step for reaching high levels of stereoselectivity was demonstrated to be the resolution of the α-CF₃-alcohol using (S)-ibuprofen as ...
DOI:
10.1039/d1cc04556c

83. 2,2′-Disubstituted F₁₂binaphthyl derivatives: stannanes, boranes, and (R)-F₁₂BINOL

Author:
Darryl J. Morrison; Susanne D. Riegel; Warren E. Piers; Masood Parvez; Robert McDonald
Source:
Chemical communications 2006 v. no.27 pp. 2875-2877
ISSN:
1364-548X
Subject:
boranes; enantiomers; organochlorine compounds; oxidation
Abstract:
... 2,2′-Distannyl derivatives of dodecafluorobinaphthalene are converted to a novel D₂ symmetric borane dimer, which can be oxidized to (±)-F₁₂BINOL; resolution using (S)-acetoxypropanoyl chloride affords enantiopure material. ...
DOI:
10.1039/b605716k

84. 2,5,6,9,10-Pentabromocyclododecanols (PBCDOHs): A new class of HBCD transformation products

Author:
Norbert V. Heeb; Daniel Zindel; W. Bernd Schweizer; Peter Lienemann
Source:
Chemosphere 2012 v.88 no.5 pp. 655-662
ISSN:
0045-6535
Subject:
bromination; byproducts; crystal structure; enantiomers; isotopes; mass spectrometry; metabolites; polystyrenes; stereochemistry
Abstract:
... Pentabromocyclododecanols (PBCDOHs) are potential environmental transformation products of hexabromocyclododecanes (HBCDs). They are also potential stage one metabolites of biological HBCD transformations. Herein, we present analytical evidence that PBCDOHs are also constituents of technical HBCDs and flame-proofed polystyrenes (FP-PSs). PBCDOHs are possibly formed during the synthesis of technica ...
DOI:
10.1016/j.chemosphere.2012.03.052
PubMed:
22520970

85. 2-(2-Phenylethyl)chromone derivatives: Promising α-glucosidase inhibitors in agarwood from Aquilaria filaria

Author:
Cheng-neng Mi; Jing-zhe Yuan; Man-man Zhu; Li Yang; Yan-mei Wei; Hao Wang; Wen-xing Long; Wen-li Mei; Hao-fu Dai
Source:
Phytochemistry 2021 v.181 pp. 112578
ISSN:
0031-9422
Subject:
Aquilaria; acarbose; enantiomers; ethyl acetate; genistein; spectroscopy
Abstract:
... Twelve undescribed 2-(2-phenylethyl)chromone derivatives, including one pair of enantiomers, together with eleven known ones, were isolated from the EtOAc extract of agarwood originating from Aquilaria filaria. All structures were elucidated by spectroscopic (NMR, UV, IR, MS) methods and compared with reported data in literatures. Twenty-one compounds were assessed for α-glucosidase inhibitory act ...
DOI:
10.1016/j.phytochem.2020.112578

86. 2-(Tetrahydrofuran-2-yl)acetic Acid and Ester Derivatives as Long-Range Pollinator Attractants in the Sexually Deceptive Orchid Cryptostylis ovata

Author:
Björn Bohman; Alyssa M. Weinstein; Ryan D. Phillips; Rod Peakall; Gavin R. Flematti
Source:
Journal of natural products 2019 v.82 no.5 pp. 1107-1113
ISSN:
1520-6025
Subject:
Orchidaceae; acetic acid; attractants; bioassays; ejaculation; enantiomers; females; flowers; high performance liquid chromatography; insects; males; pollination; pollinators; semiochemicals; solvents
Abstract:
... Sexually deceptive orchids achieve pollination by luring male insects to flowers through chemical and sometimes visual mimicry of females. An extreme example of this deception occurs in Cryptostylis, one of only two genera where sexual deception is known to induce pollinator ejaculation. In the present study, bioassay-guided fractionations of Cryptostylis solvent extracts in combination with field ...
DOI:
10.1021/acs.jnatprod.8b00772

87. 2-Acyl-dimedones as UV-active protective agents for chiral amino acids: enantiomer separations of the derivatives on chiral anion exchangers

Author:
Stefanie Wernisch; Francesca Bisi; Addolorata S. Cazzato; Michal Kohout; Wolfgang Lindner
Source:
Analytical and bioanalytical chemistry 2013 v.405 no.25 pp. 8011-8026
ISSN:
1618-2642
Subject:
acids; amino acid derivatives; amino acids; analytical methods; enantiomers; hydrazine; primary amines
Abstract:
... 2-Acetyldimedone and 12 related compounds were employed as UV-active pre-column derivatizing agents for amino acids. Direct enantioseparation of the products was achieved using chiral anion exchanger stationary phases in polar-organic mobile phase mode. Under basic conditions, the reagents´ cyclic β-tricarbonyl motifs can give rise to exo- and endocyclic enols through tautomerization. However, wit ...
DOI:
10.1007/s00216-013-6932-z

88. 2-Bromo[6]helicene as a Key Intermediate for [6]Helicene Functionalization

Author:
Martin Jakubec; Tomáš Beránek; Pavel Jakubík; Jan Sýkora; Jaroslav Žádný; Vladimír Církva; Jan Storch
Source:
Journal of organic chemistry 2018 v.83 no.7 pp. 3607-3616
ISSN:
1520-6904
Subject:
boron; carbon; chemical reactions; enantiomers; nitrogen; organic chemistry; organic compounds; oxygen; phosphorus; sulfur
Abstract:
... The synthesis of 2-bromo[6]helicene was revised and improved up to 51% yield. Its reactivity was thoroughly investigated, and a library of 17 different carbon, boron, nitrogen, phosphorus, oxygen and sulfur substituted derivatives was prepared. The racemization barrier for 2-bromo[6]helicene was determined, and the usage of enantiomers in the synthesis of optically pure helicenes was rationalized. ...
DOI:
10.1021/acs.joc.7b03234

89. 2-Methylbutyl acetate in wines: Enantiomeric distribution and sensory impact on red wine fruity aroma

Author:
Margaux Cameleyre; Georgia Lytra; Sophie Tempere; Jean-Christophe Barbe
Source:
Food chemistry 2017 v.237 pp. 364-371
ISSN:
0308-8146
Subject:
acetates; alcohols; bananas; enantiomers; gamma-cyclodextrin; gas chromatography; odors; red wines; sensory evaluation; white wines
Abstract:
... Enantiomers of 2-methylbutyl acetate were assayed in red and white commercial wines from various vintages and origins, using chiral gas chromatography (γ-cyclodextrin), revealing the exclusive presence of the S-enantiomeric form. Results also confirmed that (S)-2-methylbutyl acetate levels were generally higher in red than white wines of the same age, and that acetate levels increased gradually du ...
DOI:
10.1016/j.foodchem.2017.05.093

90. 2-OMe-lysophosphatidylcholine analogues are GPR119 ligands and activate insulin secretion from βTC-3 pancreatic cells: Evaluation of structure-dependent biological activity

Author:
Anna Drzazga; Agata Sowińska; Agnieszka Krzemińska; Andrzej Okruszek; Piotr Paneth; Maria Koziołkiewicz; Edyta Gendaszewska-Darmach
Source:
BBA - Molecular and Cell Biology of Lipids 2017 pp. -
ISSN:
1388-1981
Subject:
agonists; bioactive properties; bioassays; calcium; cyclic AMP; enantiomers; glucose; homeostasis; insulin secretion; islets of Langerhans; ligands; lysophosphatidylcholine; mice; molecular models; noninsulin-dependent diabetes mellitus; oleic acid; optical isomerism
Abstract:
... GPR119 receptor has been proposed as a metabolic regulator playing a pivotal role in the modulation of glucose homeostasis in type 2 diabetes. GPR119 was identified on pancreatic β cells and its ligands have the ability to enhance glucose-stimulated insulin secretion (GSIS). Lysophosphatidylcholine (LPC) was shown to potentiate GSIS and our present studies indicate that 2-methoxy-lysophosphatidylc ...
DOI:
10.1016/j.bbalip.2017.10.004

91. 2-Pyridylsulfinamides as effective catalysts in the asymmetric alkylation of aldehydes with diethylzinc

Author:
Kavirayani R. Prasad; Omkar Revu
Source:
Tetrahedron 2013 v.69 pp. 8422-8428
ISSN:
0040-4020
Subject:
aldehydes; alkylation; catalysts; diastereomers; enantiomers; nitrogen; phenylethyl alcohol; stereoisomerism; sulfur
Abstract:
... Chiral 2-pyridylsulfinamides were shown to be effective catalysts in the alkylation of aryl and alkyl aldehydes with diethylzinc providing the corresponding alcohols in excellent enantioselectivity. Sulfinamide catalysts possessing solitary chirality at the sulfur center produced the product phenethyl alcohol in good enantioselectivity. Diastereomeric sulfinamides possessing chirality at the carbo ...
DOI:
10.1016/j.tet.2013.07.061

92. 2‐Methylisocitrate lyases from the bacterium Escherichia coli and the filamentous fungus Aspergillus nidulans: Characterization and comparison of both enzymes

Author:
Matthias Brock; Dan Darley; Susanne Textor; Wolfgang Buckel
Source:
European journal of biochemistry 2001 v.268 no.12 pp. 3577-3586
ISSN:
0014-2956
Subject:
Aspergillus nidulans; Escherichia coli; Streptomyces hygroscopicus; bacteria; cysteine; enantiomers; fungi; gel chromatography; high performance liquid chromatography; isocitrate lyase; molecular weight; operon; oxidation; prions; propionic acid; pyruvic acid; sequence analysis; succinic acid
Abstract:
... In Escherichia coli and Aspergillus nidulans, propionate is oxidized to pyruvate via the methylcitrate cycle. The last step of this cycle, the cleavage of 2‐methylisocitrate to succinate and pyruvate is catalysed by 2‐methylisocitrate lyase. The enzymes from both organisms were assayed with chemically synthesized threo‐2‐methylisocitrate; the erythro‐diastereomer was not active. 2‐Meth ...
DOI:
10.1046/j.1432-1327.2001.02262.x

93. 2′-Aminoanalogues of the cruciferous phytoalexins spirobrassinin, 1-methoxyspirobrassinin and 1-methoxyspirobrassinol methyl ether: Synthesis and anticancer properties

Author:
Mariana Budovská; Viera Tischlerová; Ján Mojžiš; Marianna Harvanová; Oleksandr Kozlov; Taťána Gondová; Nataša Tomášková
Source:
Tetrahedron 2017 pp. -
ISSN:
0040-4020
Subject:
aniline; antineoplastic activity; chemical reactions; enantiomers; high performance liquid chromatography; humans; neoplasms; nuclear magnetic resonance spectroscopy; phytoalexins; solvents
Abstract:
... A method for the synthesis of new 2′-aminoanalogues of spiroindoline phytoalexins is reported. 2′-Aminonalogues of spirobrassinin, 1-methoxyspirobrassinin and 2,2′-diamino analogues of 1-methoxyspirobrassinol methyl ether were prepared by substitution of the methylsulphanyl group on the dihydrothiazole ring of corresponding phytoalexins. Final products were obtained by heating the phytoalexins wit ...
DOI:
10.1016/j.tet.2017.09.033

94. 3-(Dialkoxyphosphoryl)-N-confused Phlorin and Porphyrin. Synthesis, Stereochemistry, and Coordination Properties

Author:
Liu Bin; Li Xiaofang; Xu Xin; Stępień Marcin; Chmielewski Piotr J.
Source:
Journal of organic chemistry 2013 v.78 no.4 pp. 1354-1364
ISSN:
1520-6904
Subject:
X-radiation; acetic acid; benzoquinones; circular dichroism spectroscopy; enantiomers; high performance liquid chromatography; hydrogen; nickel; organic chemistry; oxidation; porphyrins; stereochemistry
Abstract:
... A 3-phosphonated N-confused phlorin 3 was synthesized by the reaction of N-confused porphyrin 1 and trimethyl or triethyl phosphite 2 in the presence of acetic acid in good yield. The presence of hydrogen and aryl substituents in one of the meso positions (C5) generates a stereogenic center, resulting in configurationally stable enantiomers. The enantiomers were separated by HPLC and characterized ...
DOI:
10.1021/jo302689d

95. 3-(Phenyl-4-oxy)-5-phenyl-4,5-dihydro-(1H)-pyrazole: A fascinating molecular framework to study the enantioseparation ability of the amylose (3,5-dimethylphenylcarbamate) chiral stationary phase. Part I. Structure-enantioselectivity relationships

Author:
Simone Carradori; Marco Pierini; Sergio Menta; Daniela Secci; Rossella Fioravanti; Roberto Cirilli
Source:
Journal of chromatography 2016 v.1467 pp. 221-227
ISSN:
0021-9673
Subject:
amylose; enantiomers; high performance liquid chromatography; methanol; molecular models; supercritical fluid chromatography
Abstract:
... Chiral stationary phases (CSPs) based on amylose (3,5-dimethylphenylcarbamate) (ADMPC) exhibit a wide-range of enantioselectivity in high-performance liquid chromatography (HPLC) and supercritical fluid chromatography (SFC). Although this class of CSPs has been extensively used, chiral discriminations at receptorial level, which are useful to develop predictive molecular models, have been rarely r ...
DOI:
10.1016/j.chroma.2016.07.034

96. 3-(Phenyl-4-oxy)-5-phenyl-4,5-dihydro-(1H)-pyrazole: A fascinating molecular framework to study the enantioseparation ability of the amylose (3,5-dimethylphenylcarbamate) chiral stationary phase. Part II. Solvophobic effects in enantiorecognition process

Author:
Marco Pierini; Simone Carradori; Sergio Menta; Daniela Secci; Roberto Cirilli
Source:
Journal of chromatography 2017 pp. -
ISSN:
0021-9673
Subject:
alcohols; amylose; carbon; chromatography; enantiomers; oxygen; temperature
Abstract:
... The enantiomers of five chiral compounds incorporating the 3-(phenyl-4-oxy)-5-phenyl-4,5-dihydro-(1H)-pyrazole scaffold and differing only in the linear alkyl chain (varying in length from 1 to 5 carbon atoms) linked to the oxygen atom were directly separated on the amylose (3,5-dimethylphenylcarbamate) based Chiralpak AD-3 chiral stationary phase. The effects of the mobile phase composition, the ...
DOI:
10.1016/j.chroma.2017.04.001

97. 3-Arylisoindolinone and sesquiterpene derivatives from the mangrove endophytic fungi Aspergillus versicolor SYSU-SKS025

Author:
Hui Cui; Yena Liu; Tingmei Li; Zhengrui Zhang; Meng Ding; Yuhua Long; Zhigang She
Source:
Fitoterapia 2017 pp. -
ISSN:
0367-326X
Subject:
Aspergillus versicolor; X-ray diffraction; alpha-glucosidase; enantiomers; endophytes; fungi; inhibitory concentration 50; macrophages; medicinal plants; nitric oxide; nuclear magnetic resonance spectroscopy; sesquiterpenoids; spectral analysis
Abstract:
... A pair of 3-arylisoindolinone enantiomers: (+)-asperglactam A (1), (−)-asperglactam A (1) and a pair of nor-bisabolane enantiomers: (+)-1-hydroxyboivinianic acid (2), (−)-1-hydroxyboivinianic acid (2), along with seven known compounds (3−8) were obtained from the mangrove endophytic fungus Aspergillus versicolor SYSU-SKS025. Their structures were determined on the basis of HRESIMS and NMR spectros ...
DOI:
10.1016/j.fitote.2017.11.006

98. 3. Easier access to “fossil gelatin” and quality check by amino acid racemization

Author:
Hartwig Elster
Source:
Palaeogeography, palaeoclimatology, palaeoecology 2019 v.526 pp. 43-52
ISSN:
0031-0182
Subject:
aspartic acid; bones; cleaning; enantiomers; fossils; gas chromatography; gelatin; mass spectrometry; polymers; stable isotopes
Abstract:
... Gelatin in fossil bones is the most important source for radiocarbon, stable isotopes, ZooMS (Zooarchaeology by Mass Spectrometry) and Amino Acid Racemization (AAR) studies. The isolation and cleaning of fossil gelatin is a time consuming procedure and can introduce contaminations, which, as a consequence, can produce erroneous results.By synthesizing and optimizing a “Molecularly Imprinted Polyme ...
DOI:
10.1016/j.palaeo.2019.04.014

99. 4-Plex Chemical Labeling Strategy Based on Cinchona Alkaloid-Derived Primary Amines for the Analysis of Chiral Carboxylic Acids by Liquid Chromatography-Mass Spectrometry

Author:
Jie Zheng; Shu-Jian Zheng; Chu-Bo Qi; Dong-Mei Wu; Yu-Qi Feng
Source:
Analytical chemistry 2019 v.91 no.17 pp. 11440-11446
ISSN:
1520-6882
Subject:
Cinchona; bioactive properties; blood serum; carboxylic acids; chemical species; colorectal neoplasms; detection limit; enantiomers; energy metabolism; humans; liquid chromatography; mass spectrometry; noninsulin-dependent diabetes mellitus; pathogenesis; patients; primary amines; signal transduction
Abstract:
... Chiral carboxylic acids play important roles in energy metabolism and signal transduction in the human body. These enantiomers usually possess different bioactivities and are also associated with the development of some diseases. Therefore, simultaneous determination of multiple chiral carboxylic acids is vital for study of the pathogenesis of related diseases. However, it is still challenging to ...
DOI:
10.1021/acs.analchem.9b02909

100. 5,6-δ-DHTL, a stable metabolite of arachidonic acid, is a potential substrate for paraoxonase 1

Author:
Suzy Eryanni-Levin; Soliman Khatib; Reut Levy-Rosenzvig; Snait Tamir; Andrea Szuchman-Sapir
Source:
Biochimica et biophysica acta 2015 v.1851 no.9 pp. 1118-1122
ISSN:
1388-1981
Subject:
Gibbs free energy; arachidonic acid; aryldialkylphosphatase; correlation; cytochrome P-450; enantiomers; energy; epoxide hydrolase; hydrolysis; hypotension; kinetics; knockout mutants; liquid chromatography; mass spectrometry; metabolites; mice; vasodilation
Abstract:
... Paraoxonase 1 (PON1) is an antiatherogenic high density lipoprotein-associated lactonase. Recent findings revealed that PON1 knockout mice have low blood pressure, which is negatively correlated with the level of 5,6-epoxyeicosatrienoic acid (5,6-EET), a cytochrome P450 -derived arachidonic acid metabolite. 5,6-EET is an endothelium-derived hyperpolarizing factor that causes arterial dilation. Und ...
DOI:
10.1016/j.bbalip.2015.04.008