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1. A Concise Asymmetric Total Synthesis of (+)-Epilupinine

Author:
Tsutsumi, Tomohiro; Karanjit, Sangita; Nakayama, Atsushi; Namba, Kosuke
Source:
Organic letters 2019 v.21 no.8 pp. 2620-2624
ISSN:
1523-7052
Subject:
proline,   etc   ; alkylation; moieties; organic compounds; oxidation; ozone;     Show all 6 Subjects
Abstract:
... Asymmetric total synthesis of (+)-epilupinine was achieved in just three steps using only commercially available common reagents. The total synthesis involved alkylations of N-nosylamide, ozone oxidation, and sequential reactions of the removal of the nosyl group, intramolecular dehydrative condensation, intramolecular Mannich reaction catalyzed by l-proline, and a reduction. ...
DOI:
10.1021/acs.orglett.9b00607

2. Total Synthesis and Structural Elucidation of (−)-Cephalezomine G

Author:
Jeon, Hongjun; Cho, Hyunkyung; Kim, Sanghee
Source:
Organic letters 2019 v.21 no.4 pp. 1121-1124
ISSN:
1523-7052
Subject:
proline,   etc   ; moieties; optical isomerism; organic compounds; stereoselectivity;     Show all 5 Subjects
Abstract:
... The first asymmetric synthesis and configurational elucidation of (−)-cephalezomine G was achieved. The highly functionalized Cα-substituted proline derivative was prepared from d-proline as the only chiral source via a C → N → C chirality transfer method consisting of stereoselective N-allylation and [2,3]-Stevens rearrangement. The azaspiranic tetracyclic backbone was constructed using ring-clos ...
DOI:
10.1021/acs.orglett.9b00036

3. Construction of Challenging Proline–Proline Junctions via Diselenide–Selenoester Ligation Chemistry

Author:
Sayers, Jessica; Karpati, Phillip M. T.; Mitchell, Nicholas J.; Goldys, Anna M.; Kwong, Stephen M.; Firth, Neville; Chan, Bun; Payne, Richard J.
Source:
Journal of the American Chemical Society 2018 v.140 no.41 pp. 13327-13334
ISSN:
1520-5126
Subject:
proline,   etc   ; moieties; polypeptides; proteins;     Show all 4 Subjects
Abstract:
... Polyproline sequences are highly abundant in prokaryotic and eukaryotic proteins, where they serve as key components of secondary structure. To date, construction of the proline–proline motif has not been possible owing to steric congestion at the ligation junction, together with an n → π* electronic interaction that reduces the reactivity of acylated proline residues at the C-terminus of peptides ...
DOI:
10.1021/jacs.8b07877

4. Synthesis of new fluorinated proline analogues from polyfluoroalkyl β-ketoacetals and ethyl isocyanoacetate

Author:
Tolmachova, Nataliya A.; Kondratov, Ivan S.; Dolovanyuk, Violetta G.; Pridma, Stanislav O.; Chernykh, Anton V.; Daniliuc, Constantin G.; Haufe, Günter
Source:
Chemical communications 2018 v.54 no.69 pp. 9683-9686
ISSN:
1364-548X
Subject:
proline,   etc   ; chemical compounds; chemical reactions;     Show all 3 Subjects
Abstract:
... The reaction of trifluoroaldol acetal and other polyfluoroalkyl β-ketoacetals with ethyl isocyanoacetate was applied for the preparation of hitherto unknown fluorinated amino acids, cis- and trans-3-CF₃/C₂F₅-prolines as well as trans-3-CF₂Br/CF₂Cl/CHF₂-3-hydroxyprolines. ...
DOI:
10.1039/c8cc05912h

5. Quantifying both ammonium and proline in wines and beer by using a PDMS composite for sensoring

Author:
Prieto-Blanco, María Carmen; Jornet-Martinez, Neus; Verdú-Andrés, Jorge; Molíns-Legua, Carmen; Campíns-Falcó, Pilar
Source:
Talanta 2019 v.198 pp. 371-376
ISSN:
0039-9140
Subject:
proline,   etc   ; ammonium; beers; cost effectiveness; detection limit; nitroprusside; thymol; wines;     Show all 8 Subjects
Abstract:
... Two of the reagents involved in the Berthelot's reaction, thymol and nitroprusside, were embedded in a PDMS composite in order to apply this assay to determine ammonium and proline, in wine and beers. Safety, portability, rapidity, cost-effectiveness and simplicity of the assay were improved. For the proline determination, a modified Berthelot's reaction, which included a ring cleavage of proline, ...
DOI:
10.1016/j.talanta.2019.02.001

6. Comparison between Fenton and Fenton-like reactions for L-proline degradation

Author:
Rodríguez-Narváez, O. M.; Pérez, L. S.; Yee, N. G.; Peralta-Hernández, J. M.; Bandala, E. R.
Source:
International journal of environmental science and technology 2019 v.16 no.3 pp. 1515-1526
ISSN:
1735-1472
Subject:
proline,   etc   ; cobalt; irradiation; leachates; oxidants; pH; risk; toxicity; ultraviolet radiation;     Show all 9 Subjects
Abstract:
... Fe/H₂O₂ and Co/PMS reactions were compared for L-proline degradation under different initial pH values, various transition metal salt and oxidant agent concentrations, as well with and without irradiation. The Fenton reaction took 60 min to degrade 90% of the L-proline, whereas the Fenton-like reaction achieved the same degradation after only 15 min. The best conditions for the Fenton-like reactio ...
DOI:
10.1007/s13762-018-1764-1

7. Synthesis and Conformational Properties of 3,4-Difluoro-l-prolines

Author:
Hofman, Gert-Jan; Ottoy, Emile; Light, Mark E.; Kieffer, Bruno; Martins, Jose C.; Kuprov, Ilya; Sinnaeve, Davy; Linclau, Bruno
Source:
Journal of organic chemistry 2019 v.84 no.6 pp. 3100-3120
ISSN:
1520-6904
Subject:
proline,   etc   ; diastereomers; isomerization; organic chemistry; organic compounds; stereochemistry;     Show all 6 Subjects
Abstract:
... Fluorinated proline derivatives have found diverse applications in areas ranging from medicinal chemistry over structural biochemistry to organocatalysis. Depending on the stereochemistry of monofluorination at the proline 3- or 4-position, different effects on the conformational properties of proline (ring pucker, cis/trans isomerization) are introduced. With fluorination at both 3- and 4-positio ...
DOI:
10.1021/acs.joc.8b02920

8. Synthesis of di- and trihydroxy proline derivatives from D-glycals: Application in the synthesis of polysubstituted pyrrolizidines and bioactive 1C-aryl/alkyl pyrrolidines

Author:
Verma, Ashish Kumar; Dubbu, Sateesh; Chennaiah, Ande; Vankar, Yashwant D.
Source:
Carbohydrate research 2019
ISSN:
0008-6215
Subject:
proline,   etc   ; amination; carbohydrates; cycloaddition reactions; pyrrolidines; stereoselective synthesis; stereoselectivity;     Show all 7 Subjects
Abstract:
... Six different types of O-benzyl protected proline derivatives have been synthesized from D-glycals and 2C-formyl-glycals. One of the di-O-benzyl protected proline derivatives has been utilized for the synthesis of polysubstituted pyrrolizidines via [3 + 2] cycloaddition in a stereoselective manner. Further, we also report on the stereoselective synthesis of biologically active 1C-aryl/alkyl pyrrol ...
DOI:
10.1016/j.carres.2019.02.004

9. Replacement of ProB28 by pipecolic acid protects insulin against fibrillation and slows hexamer dissociation

Author:
Fang, Katharine Y.; Lieblich, Seth A.; Tirrell, David A.
Source:
Journal of polymer science 2019 v.57 no.3 pp. 264-267
ISSN:
0887-624X
Subject:
proline,   etc   ; dissociation; engineering; insulin; mutagenesis; pipecolic acid; polymers; therapeutics;     Show all 8 Subjects
Abstract:
... Non‐canonical amino acid mutagenesis was used to examine the biophysical consequences of changing ring size and structure at the single proline site in insulin. Addition of a methylene spacer to the prolyl ring (by replacement of proline by pipecolic acid at position B28) led to an increase in stability and a decrease in the rate of hexamer dissociation. The results of this work illustrate the pow ...
DOI:
10.1002/pola.29225

10. Diversity-oriented one-pot multicomponent synthesis of chromanone-based 3,3′-pyrrolidinyl-spirooxindoles via a 1,3-dipolar cycloaddition reaction

Author:
Yue, Jing; Chen, Shuang; Zuo, Xiong; Liu, Xiong-Li; Xu, Sheng-Wen; Zhou, Ying
Source:
Tetrahedron letters 2019 v.60 no.2 pp. 137-141
ISSN:
0040-4039
Subject:
proline,   etc   ; chemical structure; cycloaddition reactions; decarboxylation; organic compounds; stereochemistry; stereoselectivity;     Show all 7 Subjects
Abstract:
... A new methodology was developed for the highly efficient one-pot multicomponent synthesis of chromanone-based 3,3′-pyrrolidinyl-spirooxindoles via a 1,3-dipolar cycloaddition reaction of chromones 1 with azomethine ylides (thermally generated in situ from isatins and proline or thioproline). Another valuable application of this method was for the less reactive chromone through a carboxylic acid-ac ...
DOI:
10.1016/j.tetlet.2018.11.075

11. δ-Azaproline: A versatile tool to design pseudopeptides by its incorporation via Nε or Nδ atoms

Author:
Ovdiichuk, Olga; Flauder, Lucie; Humbert-Voss, Emelyne; Jamart-Grégoire, Brigitte; Arrault, Axelle
Source:
Tetrahedron letters 2019 v.60 no.1 pp. 16-19
ISSN:
0040-4039
Subject:
proline,   etc   ; alanine; chemical reactions; chemical structure; nitrogen; organic compounds;     Show all 6 Subjects
Abstract:
... δ-Azaproline, a bis-nitrogen proline, has been incorporated in pseudotripeptides of the type Xaa1-δazaPro-Xaa3. Peptide elongation via both nitrogen atoms has been explored by peptide coupling with glycine and/or alanine amino acids showing higher reactivity though an extra Nδ atom compare to the native Nε extremity. Carbonyls of some pseudopeptides have been converted into their thioanalogues. Th ...
DOI:
10.1016/j.tetlet.2018.11.042

12. Enantioselective addition of diethylzinc to aldehydes catalyzed by 5-cis-substituted proline derivatives

Author:
Prause, Felix; Wagner, Stefan; Breuning, Matthias
Source:
Tetrahedron 2019 v.75 no.1 pp. 94-101
ISSN:
0040-4020
Subject:
proline,   etc   ; aldehydes; catalysts; enantioselectivity; ligands; moieties; optical isomerism; stereochemistry; sulfonamides;     Show all 9 Subjects
Abstract:
... 5-Cis-substituted prolinols, prolinamines, and prolinamine sulfonamides proved to be efficient ligands for the enantioselective addition of diethylzinc to aldehydes, providing up to 99% ee. The sense of asymmetric induction can be controlled by the nature of the exocyclic functional group (CPh2OH vs. CH2NHR vs. CH2NHSO3R). The additional 5-cis substituent exerts a strong beneficial effect on the c ...
DOI:
10.1016/j.tet.2018.11.030

13. Direct synthesis of N-sulfinyl- and N-sulfonylimines via copper/l-proline-catalyzed aerobic oxidative cascade reaction of alcohols with sulfinamides or sulfonamides

Author:
Zhang, Guofu; Xu, Shengjun; Xie, Xiaoqiang; Ding, Chengrong; Shan, Shang
Source:
RSC advances 2017 v.7 no.16 pp. 9431-9435
ISSN:
2046-2069
Subject:
proline,   etc   ; moieties; sulfonamides;     Show all 3 Subjects
Abstract:
... An efficient one-pot synthetic method of N-sulfinyl- and N-sulfonylimines by the condensation of alcohols with sulfinamides or sulfonamides under mild and green conditions has been developed using a combination of CuI, l-proline and TEMPO. This system shows excellent functional group compatibility for a wide range of substrates and affords the corresponding products in good to excellent yields. ...
DOI:
10.1039/c6ra26490e

14. Residue-Specific Conformational Heterogeneity of Proline-Rich Sequences Uncovered via Infrared Spectroscopy

Author:
Bukowski, Gregory S.; Thielges, Megan C.
Source:
Analytical chemistry 2018 v.90 no.24 pp. 14355-14362
ISSN:
1520-6882
Subject:
proline,   etc   ; carbon; deuterium; infrared spectroscopy; peptides; proteins;     Show all 6 Subjects
Abstract:
... Conformational heterogeneity is critical to understanding protein function but challenging to quantify. Experimental approaches that can provide sufficient temporal and spatial resolution to measure even rapidly interconverting states at specific locations in proteins are needed to fully elucidate the contribution of conformational heterogeneity and dynamics to function. Infrared spectroscopy in c ...
DOI:
10.1021/acs.analchem.8b03813

15. Chiral Ramachandran Plots II: General Trends and Protein Chirality Spectra

Author:
Wang, Huan; Avnir, David; Tuvi-Arad, Inbal
Source:
Biochemistry 2018 v.57 no.45 pp. 6395-6403
ISSN:
1520-4995
Subject:
proline,   etc   ; optical isomerism; proteins; statistical analysis;     Show all 4 Subjects
Abstract:
... The degree of chirality of protein backbone residues is used to enrich the Ramachandran plot (RP) and create three-dimensional chiral RPs with much more structural information. Detailed comparative analysis of the four classical RPs (general, glycine, proline, and pre-proline) is provided, including statistical analysis of quantitative chirality distributions in the maps and in the secondary struc ...
DOI:
10.1021/acs.biochem.8b00974

16. Investigating the role of loop 131–140 in activity and thermal stability of chondroitinase ABC I

Author:
Kheirollahi, Asma; Khajeh, Khosro; Golestani, Abolfazl
Source:
International journal of biological macromolecules 2018 v.116 pp. 811-816
ISSN:
0141-8130
Subject:
proline,   etc   ; catalytic activity; mutants; mutation; thermal stability;     Show all 5 Subjects
Abstract:
... Previously, we attempted to improve the thermostability of chondroitinase ABC I by substituting proline in flexible sites and successfully obtained a mutant; E138P, with increased thermostability (Kheirollahi et al., 2017). In this study, we focused on the role of Glu138 in activity and stability of the enzyme using its further mutation to Ala, Lys, and Asp. Moreover, we coupled the two mutations ...
DOI:
10.1016/j.ijbiomac.2018.05.094

17. Pyrrolidine and oxazolidine ring transformations in proline and serine derivatives of α-hydroxyphosphonates induced by deoxyfluorinating reagents

Author:
Kaczmarek, Patrycja; Rapp, Magdalena; Koroniak, Henryk
Source:
RSC advances 2018 v.8 no.43 pp. 24444-24457
ISSN:
2046-2069
Subject:
proline,   etc   ; aziridines; diastereomers; phosphonates; piperidines; serine;     Show all 6 Subjects
Abstract:
... Transformations of α-hydroxyphosphonates derived from proline or serine by treatment with different deoxyfluorinating reagents (DAST, Deoxofluor, PyFluor) are reported. Depending on the applied reagent, as well as the protecting group used (N-Cbz, N-Boc, N-Bn) different types of products are observed. The reaction of N-Cbz or N-Boc prolinols with DAST or Deoxofluor due to aziridinium intermediate ...
DOI:
10.1039/c8ra05186k

18. Trifluoromethylated proline analogues as efficient tools to enhance the hydrophobicity and to promote passive diffusion transport of the l-prolyl-l-leucyl glycinamide (PLG) tripeptide

Author:
Oliver, Martin; Gadais, Charlène; García-Pindado, Júlia; Teixidó, Meritxell; Lensen, Nathalie; Chaume, Grégory; Brigaud, Thierry
Source:
RSC advances 2018 v.8 no.26 pp. 14597-14602
ISSN:
2046-2069
Subject:
proline,   etc   ; amino acid sequences; diffusion; hydrophobicity; synthesis;     Show all 5 Subjects
Abstract:
... The synthesis of four CF₃-proline analogues of the PLG peptide is reported. Our results show that the incorporation of trifluoromethylated amino acids (Tfm-AAs) at the N-terminal position of a peptide significantly increases its hydrophobicity. In addition, depending on the relative configuration and the position of the CF₃ group, Tfm-AAs can also promote passive diffusion transport. ...
DOI:
10.1039/c8ra02511h

19. 2-Oxoglutarate regulates binding of hydroxylated hypoxia-inducible factor to prolyl hydroxylase domain 2

Author:
Abboud, Martine I.; McAllister, Tom E.; Leung, Ivanhoe K. H.; Chowdhury, Rasheduzzaman; Jorgensen, Christian; Domene, Carmen; Mecinović, Jasmin; Lippl, Kerstin; Hancock, Rebecca L.; Hopkinson, Richard J.; Kawamura, Akane; Claridge, Timothy D. W.; Schofield, Christopher J.
Source:
Chemical communications 2018 v.54 no.25 pp. 3130-3133
ISSN:
1364-548X
Subject:
procollagen-proline dioxygenase,   etc   ; animals; hydroxylation; hypoxia; iron;     Show all 5 Subjects
Abstract:
... Prolyl hydroxylation of hypoxia inducible factor (HIF)-α, as catalysed by the Fe(ii)/2-oxoglutarate (2OG)-dependent prolyl hydroxylase domain (PHD) enzymes, has a hypoxia sensing role in animals. We report that binding of prolyl-hydroxylated HIF-α to PHD2 is ∼50 fold hindered by prior 2OG binding; thus, when 2OG is limiting, HIF-α degradation might be inhibited by PHD binding. ...
DOI:
10.1039/c8cc00387d

20. Liquid chromatographic resolution of proline and pipecolic acid derivatives on chiral stationary phases based on (+)‐(18‐crown‐6)‐2,3,11,12‐tetracarboxylic acid

Author:
Cho, Eun Sol; Sung, Ji Yeong; Jin, Jong Sung; Hyun, Myung Ho
Source:
Journal of separation science 2018 v.41 no.6 pp. 1192-1198
ISSN:
1615-9306
Subject:
proline,   etc   ; aniline; liquid chromatography; pipecolic acid;     Show all 4 Subjects
Abstract:
... Two liquid chromatographic chiral stationary phases based on (+)‐(18‐crown‐6)‐2,3,11,12‐tetracarboxylic acid were applied to the resolution of the amide derivatives of cyclic α‐amino acids including proline and pipecolic acid. Among the five amide derivatives of proline, aniline amide was resolved best on the first chiral stationary phase, which contains two N–H tethering amide groups, with the se ...
DOI:
10.1002/jssc.201700996