U.S. flag

An official website of the United States government

Dot gov

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Https

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

PubAg

Main content area

You searched for: Subject chemical structure Remove constraint Subject: chemical structure Subject spectral analysis Remove constraint Subject: spectral analysis
Start Over

Search

6,478  Search Results

« Previous | 1 - 20 of 6,478 |
Number of results to display per page

Search Results

1. Diphenyl ethers and depsidones from the endophytic fungus Aspergillus unguis BCC54176

Author:
Karoon Sadorn; Siriporn Saepua; Nantiya Bunbamrung; Nattawut Boonyuen; Somjit Komwijit; Pranee Rachtawee; Pattama Pittayakhajonwut
Source:
Tetrahedron 2022 v.105 pp. 132612
ISSN:
0040-4020
Subject:
Aspergillus; Bacillus cereus; Colletotrichum acutatum; Staphylococcus aureus; X-ray diffraction; antibacterial properties; biphenyl; chemical structure; cytotoxicity; fungi; spectral analysis
Abstract:
... Four new diphenyl ethers, aspergillusethers G−J (1–4), and one new depsidone, emeguisin D (7), together with eighteen known compounds have been isolated and characterized from the endophytic fungus Aspergillus unguis BCC54176. The chemical structures were established based on spectroscopic evidence in conjunction with a chemical transformation. Furthermore, the chemical structure of compound 7 was ...
DOI:
10.1016/j.tet.2021.132612

2. Effect of chemical structure of selected phenolic acids on the structure of gluten proteins

Author:
Renata Welc; Konrad Kłosok; Monika Szymańska-Chargot; Agnieszka Nawrocka
Source:
Food chemistry 2022 v.389 pp. 133109
ISSN:
0308-8146
Subject:
chemical structure; disulfides; food chemistry; gluten; hydrogen; spectral analysis; spectroscopy
Abstract:
... Effect of overmixing process and structure of selected phenolic acids belonging to hydroxycinnamic and hydroxybenzoic group on the structure of gluten network were analysed with application of FT-Raman Spectroscopy. Modification of gluten by acids resulted in formation of aggregates and unordered structures at the expense of protein stabilizing structures (e.g. β-sheets or β-turns). Supplementatio ...
DOI:
10.1016/j.foodchem.2022.133109

3. Inhibitory effect of ginsenglactone A from Panax ginseng on the tube formation of human umbilical vein endothelial cells and migration of human ovarian cancer cells

Author:
Dahae Lee; Ranhee Kim; So-Ri Son; Ji-Young Kim; Sungyoul Choi; Ki Sung Kang; Dae Sik Jang
Source:
Journal of Ginseng Research 2022 pp. -
ISSN:
1226-8453
Subject:
Panax ginseng; cell movement; chemical structure; gelatinase B; humans; mitogen-activated protein kinase; ovarian neoplasms; phosphatidylinositol 3-kinase; phosphorylation; rapamycin; research; spectral analysis; vascular endothelial growth factor receptor-2; vascular endothelial growth factors
Abstract:
... Here, we aimed to assess the inhibitory effect of a new compound from Panax ginseng on the migration of human ovarian cancer cells and tube formation of human umbilical vein endothelial cells (HUVECs). A new compound, ginsenglactone A (1), was isolated from ginseng roots, together with seven known compounds (2-8). Spectroscopic data were used to elucidate the chemical structure of 1. The tubular s ...
DOI:
10.1016/j.jgr.2022.08.003

4. Prenylated coumarins from the fruits of Artocarpus heterophyllus with their potential anti-inflammatory and anti-HIV activities

Author:
Lei Tao; Ya-Ting Zhuo; Ze-Hua Qiao; Juan Li; Hao-Xuan Tang; Qiao-Mei Yu; Yun-Yao Liu; Yan-Ping Liu
Source:
Natural product research 2022 v.36 no.10 pp. 2526-2533
ISSN:
1478-6427
Subject:
Artocarpus heterophyllus; RNA-directed DNA polymerase; antiretroviral agents; chemical structure; coumarin; lipopolysaccharides; macrophages; mice; phytochemicals; research; spectral analysis
Abstract:
... A phytochemical investigation on the fruits of Artocarpus heterophyllus led to the isolation and characterisation of a new prenylated coumarin, artoheteronin (1), together with six known analogues (2−7). The chemical structure of 1 was elucidated using extensive spectral methods and the known compounds (2−7) were identified by comparing their spectral data with those reported in the literature. Al ...
DOI:
10.1080/14786419.2021.1913590

5. Preparation of Fe-loaded needle coke particle electrodes and utilisation in three-dimensional electro-Fenton oxidation of coking wastewater

Author:
Yang Hu; Fuzhi Yu; Zhongteng Bai; Yanqiu Wang; Huan Zhang; Xinyu Gao; Yixian Wang; Xiao Li
Source:
Chemosphere 2022 v.308 pp. 136544
ISSN:
0045-6535
Subject:
anodes; catalytic activity; cathodes; chemical oxygen demand; chemical structure; color; electric potential difference; foams; nickel; oxidation; pH; particle size; response surface methodology; spectral analysis; temperature; total nitrogen; wastewater; water flow
Abstract:
... Novel iron-loaded needle coke spherical electrodes were fabricated for the first time using the sintering method. With DSA as the anode, nickel foam as the cathode and the spherical electrodes as the particle electrodes, a three-dimensional (3D) electro-Fenton system was constructed to treat coking wastewater. Using the chemical oxygen demand (COD) removal efficiency of coking wastewater as an ind ...
DOI:
10.1016/j.chemosphere.2022.136544

6. Raman and UVN+LWIR LIBS detection system for in-situ surface chemical identification

Author:
Clayton S.C. Yang; Dina M. Bower; Feng Jin; Tilak Hewagama; Shahid Aslam; Conor A. Nixon; John Kolasinski; Alan C. Samuels
Source:
MethodsX 2022 v.9 pp. 101647
ISSN:
2215-0161
Subject:
Raman spectroscopy; chemical structure; spectral analysis
Abstract:
... Laser Induced Breakdown Spectroscopy (LIBS) in the Ultra Violet/Visible/Near-IR (UVN) spectral range is a powerful analytical tool that facilitates the interpretation of Raman spectroscopic data by providing additional details in elemental chemistry. To acquire the complete information of molecular vibrations for more accurate and precise chemical bonding and structural analysis, an ideal in situ ...
DOI:
10.1016/j.mex.2022.101647

7. Simultaneous removal of Pb²⁺ and direct red 31 dye from contaminated water using N-(2-hydroxyethyl)-2-oxo-2H-chromene-3-carboxamide loaded chitosan nanoparticles

Author:
Mehrez E. El-Naggar; Emad K. Radwan; Huda R. M. Rashdan; Shaimaa T. El-Wakeel; Asmaa A. Koryam; Ahmed Sabt
Source:
RSC advances 2022 v.12 no.29 pp. 18923-18935
ISSN:
2046-2069
Subject:
adsorption; chemical structure; chitosan; coumarin; kinetics; models; nanocomposites; sorption isotherms; spectral analysis; trace elements; water pollution
Abstract:
... This study reports the preparation of a new material that can remove synthetic dyes and trace metals simultaneously. A new coumarin derivative was synthesized and its chemical structure was inferred from spectral data (FT-IR, ¹H-NMR, ¹³C-NMR). Meanwhile, chitosan nanoparticles (CsNPs) were prepared then used as a carrier for two different concentrations of the coumarin derivative (C1@CsNPs and C2@ ...
DOI:
10.1039/d2ra02526d

8. Synthesis, spectral analysis, quantum studies, NLO, and thermodynamic properties of the novel 5-(6-hydroxy-4-methoxy-1-benzofuran-5-ylcarbonyl)-6-amino-3-methyl-1H-pyrazolo[3,4-b] pyridine (HMBPP)

Author:
Shimaa Abdel Halim; Magdy A. Ibrahim
Source:
RSC advances 2022 v.12 no.21 pp. 13135-13153
ISSN:
2046-2069
Subject:
Lewis bases; absorption; chemical structure; cyclohexanes; energy; methanol; models; pyridines; spectral analysis; thermodynamics
Abstract:
... Ring opening followed by ring closure reactions of 4-methoxy-5-oxo-5H-furo[3,2-g] chromene-6-carbonitrile (1) with 5-amino-3-methyl-1H-pyrazole (2) afforded the novel 5-(6-hydroxy-4-methoxy-1-benzofuran-5-ylcarbonyl)-6-amino-3-methyl-1H-pyrazolo[3,4-b] pyridine (3, HMBPP). The chemical structure of the synthesized compound was established based on elemental analysis and spectral data. The chemical ...
DOI:
10.1039/d2ra01469f

9. Tetraphenylethene functionalized quinoxaline derivative exhibiting aggregation-induced emission and multi-stimuli responsive fluorescent switching

Author:
Xiuyin Xiang; Yong Zhan; Wenjun Yang
Source:
Tetrahedron 2022 v.104 pp. 132600
ISSN:
0040-4020
Subject:
chemical structure; condensation reactions; fluorescence; protonation; quantum mechanics; solvents; spectral analysis
Abstract:
... A new tetraphenylethene functionalized quinoxaline derivative TPVSQ has been synthesized using classical Knoevenagel condensation reaction. Spectral study and quantum chemical calculation indicated that it possessed D-π-A molecular structure. TPVSQ exhibited typical ICT (intramolecular charge transfer) transition and AIE property. Interestingly, TPVSQ also showed multi-stimuli responsive behavior. ...
DOI:
10.1016/j.tet.2021.132600

10. Ultra-refining for the production of long-term highly pH-stable lignin nanoparticles in high yield with high uniformity

Author:
Braz de Souza Marotti; Valdeir Arantes
Source:
Green chemistry 2022 v.24 no.3 pp. 1238-1258
ISSN:
1463-9270
Subject:
absorption; antibacterial properties; antibiotics; bioeconomics; bioethanol; chemical structure; energy; feedstocks; green chemistry; heat; lignin; mechanical methods; pH stability; particle size; spectral analysis
Abstract:
... In a bioeconomy, the valorization of lignin beyond its use to generate energy in renewable biomass-based industries is highly attractive and economically critical. However, most of its proposed applications are highly challenging and lignin remains a highly under-utilized renewable resource despite being extensively investigated. In this study, a disc ultra-refining process was used to produce lig ...
DOI:
10.1039/d1gc03525h

11. Acremonamide, a Cyclic Pentadepsipeptide with Wound-Healing Properties Isolated from a Marine-Derived Fungus of the Genus Acremonium

Author:
Sojeong Kim; Chang Wook Lee; So-Yeon Park; Ratnakar N. Asolkar; Haerin Kim; Geum Jin Kim; Song Jin Oh; Youngbae Kim; Eun-Young Lee; Dong-Chan Oh; Inho Yang; Man Jeong Paik; Hyukjae Choi; Hangun Kim; Sang-Jip Nam; William Fenical
Source:
Journal of natural products 2021 v.84 no.8 pp. 2249-2255
ISSN:
1520-6025
Subject:
Acremonium; acid hydrolysis; chemical structure; cytotoxicity; fungi; spectral analysis
Abstract:
... Acremonamide (1) was isolated from a marine-derived fungus belonging to the genus Acremonium. The chemical structure of 1 was established using MS, UV, and NMR spectroscopic data analyses. Acremonamide (1) was found to contain N-Me-Phe, N-Me-Ala, Val, Phe, and 2-hydroxyisovaleric acid. The absolute configurations of the four aforementioned amino acids were determined through acid hydrolysis follow ...
DOI:
10.1021/acs.jnatprod.1c00305

12. Applanaic acids A–C, three new highly oxygenated lanostane triterpenoids from the fruiting bodies of Ganoderma applanatum

Author:
Yu Chen; Jie Gao; Qibin Chen; Wei Liu; Yanru Qi; Haji Akber Aisa; Tao Yuan
Source:
Natural product research 2021 v.35 no.21 pp. 3918-3924
ISSN:
1478-6427
Subject:
Ganoderma applanatum; acetylcholinesterase; chemical structure; research; spectral analysis; triterpenoids
Abstract:
... Three new highly oxygenated lanostane triterpenoids, applanaic acids A–C (1–3), were isolated from the fruiting bodies of the basidiomycete Ganoderma applanatum. Among them, applanaic acid B (2) possessed the Δ¹⁷⁽²⁰⁾-double bond connection between the side chain and the tetracyclic skeleton, which was not common in the natural lanostane triterpenoids. Their structures were determined by 1D, 2D NMR ...
DOI:
10.1080/14786419.2020.1749612

13. Cadinane-type sesquiterpenes with potential anti-inflammatory and anti-HIV activities from the stems and leaves of Mappianthus iodoides

Author:
Yan-Ping Liu; Xiao-Mei Yu; Ze-Hua Qiao; Bo Jiang; Lan Xie; Hao-Xuan Tang; Xiao Liang; Yan-Hui Fu
Source:
Natural product research 2022 v.36 no.12 pp. 3078-3084
ISSN:
1478-6427
Subject:
RNA-directed DNA polymerase; antiretroviral agents; chemical structure; cortisol; nitric oxide; research; sesquiterpenoids; spectral analysis
Abstract:
... Eight cadinane-type sesquiterpenes, including a new cadinane-type sesquiterpene, named as mappianiodene (1), and seven known analogues (2–8), were isolated and identified from the stems and leaves of Mappianthus iodoides. The chemical structure and absolute configurations of 1 was elucidated by extensive spectral methods and the known compounds were identified by comparing their experimental spect ...
DOI:
10.1080/14786419.2021.1956921

14. Chemical constituents and their biological activities from the mushroom Pyropolyporus fomentarius

Author:
Fa-Lei Zhang; Chen Shi; Li-Tang Sun; Hui-Xiang Yang; Juan He; Zheng-Hui Li; Tao Feng; Ji-Kai Liu
Source:
Phytochemistry 2021 v.183 pp. 112625
ISSN:
0031-9422
Subject:
cell lines; chemical composition; chemical structure; cytotoxicity; fruiting bodies; humans; macrophages; mushrooms; neoplasm cells; nitric oxide; plant biochemistry; spectral analysis; triterpenoids
Abstract:
... The chemical constituents and their biological activities of the mushroom Pyropolyporus fomentarius were investigated in this study. Two previously undescribed pentacyclic lupane-type triterpenes, 3-formyloxybetulin and 3-formyloxybetulinic acid, two rare degraded ergosterols, pyropolincisterols A and B, along with ten known triterpenoids and four known ergosterols were isolated from the fruiting ...
DOI:
10.1016/j.phytochem.2020.112625

15. Cytotoxic sesquiterpenoids from Dysoxylum parasiticum (Osbeck) Kosterm. stem bark

Author:
Al Arofatus Naini; Tri Mayanti; Nurlelasari; Desi Harneti; Rani Maharani; Agus Safari; Ace Tatang Hidayat; Kindi Farabi; Ronny Lesmana; Unang Supratman; Yoshihito Shiono
Source:
Phytochemistry letters 2022 v.47 no. pp. 102-106
ISSN:
1874-3900
Subject:
Dysoxylum; bark; breast neoplasms; chemical structure; cytotoxicity; plant biochemistry; sesquiterpenoids; spectral analysis
Abstract:
... Two undescribed sesquiterpenoid derivatives, 10β,11-dihydroxy-1β-hydroperoxide-4αH,5αH,7βH-guaiane (1) and 10β-hydroxy-4α,4β-dimethyl-5αH,7αH-eudesm-3-one (2) along with three known of guaiane, aromadendrane, and cadinane sesquiterpenoids (3-5) were isolated from the stem bark of Dysoxylum parasiticum (Osbeck) Kosterm. The chemical structure of the compounds were determined by detailed analysis of ...
DOI:
10.1016/j.phytol.2021.11.010

16. Cytotoxic triterpenoids from the stem bark of Aglaia angustifolia

Author:
Ricson Pemimpin Hutagaol; Desi Harneti; Agus Safari; Ace Tatang Hidayat; Unang Supratman; Khalijah Awang; Yoshihito Shiono
Source:
Journal of Asian natural products research 2021 v.23 no.8 pp. 781-788
ISSN:
1477-2213
Subject:
Aglaia; bark; breast neoplasms; chemical structure; cytotoxicity; spectral analysis; triterpenoids
Abstract:
... A seco-apotirucallane-type triterpenoid, namely angustifolianin (1), along with three dammarane-type triterpenoids, (20S, 24S)-epoxy-dammarane-3β,25-diol (2), 3-epi-cabraleahydroxylactone (3), and cabralealactone (4), were isolated from the stem bark of Aglaia angustifolia Miq. The Chemical structure of the new compounds was elucidated on the basis of spectroscopic data. All of the compounds were ...
DOI:
10.1080/10286020.2020.1776704

17. Dammarane-type triterpenoid saponins from Salvia russellii Benth.

Author:
Salar Hafez Ghoran; Omidreza Firuzi; Mojtaba Asadollahi; Hermann Stuppner; Mostafa Alilou; Amir Reza Jassbi
Source:
Phytochemistry 2021 v.184 pp. 112653
ISSN:
0031-9422
Subject:
Salvia; aerial parts; assays; breasts; chemical structure; cytotoxicity; diterpenoids; humans; lung neoplasms; mass spectrometry; methylene chloride; neoplasm cells; oleanolic acid; physicochemical properties; plant biochemistry; spectral analysis; sterols; triterpenoid saponins; ursolic acid; viability
Abstract:
... Three undescribed dammarane-type saponins, russelliinosides A-C, together with a common sterol (β-sitosterol), an abietane diterpenoid (18-hydroxyferruginol), two oleane triterpenoids (daturaolone and oleanolic acid), an ursane triterpenoid (ursolic acid) as well as three 5-hydroxyflavones (cirsimaritin, eupatorin, and salvigenin) were isolated from a dichloromethane extract of the aerial parts of ...
DOI:
10.1016/j.phytochem.2020.112653

18. Delineation of molecular structure modification during coagulation of mixed camel and cow milk by mid‐infrared spectroscopy and parallel factor analysis

Author:
Oumayma Boukria; Jian Wang; Jasur Safarov; Adem Gharsallaoui; Françoise Leriche; El Mestafa El Hadrami; Abderrahmane Aït‐Kaddour
Source:
Journal of food processing and preservation 2022 v.46 no.6 pp. e15839
ISSN:
0145-8892
Subject:
camel milk; camels; casein; chemical structure; coagulation; factor analysis; milk; multivariate analysis; particle size; particle size distribution; spectral analysis; spectroscopy; wavelengths
Abstract:
... Molecular structure modifications of camel milk (CaM) and cow milk (CM) mixtures during coagulation were investigated combining mid‐infrared (MIR) spectroscopic monitoring with Parallel Factor Analysis (PARAFAC) and particle‐size measurements. To evaluate the structure evolution at the molecular level, five different milk formulations were prepared using the following volume fractions of CaM in th ...
DOI:
10.1111/jfpp.15839

19. Evaluation of antioxidant and anti-cancer properties of curcumin / beta- and gamma-cyclodextrin complexes modified with chitosan nanoparticles on lung cancer cell A549

Author:
Nina Alizadeh; Shokufeh Malakzadeh
Source:
Yāftah/hā-yi nuvīn dar ̒ulūm-i zīstī 2021 v.8 no.2 pp. 84-94
ISSN:
2476-7115
Subject:
antioxidants; chemical structure; chitosan; curcumin; drug delivery systems; gamma-cyclodextrin; hydrogen; hydrogen bonding; lung neoplasms; neoplasm cells; solubility; spectral analysis; ultraviolet-visible spectroscopy; van der Waals forces
Abstract:
... The aim of this study was to investigate the interaction modification of curcumin complex molecule (CUR) in beta- and gamma-cyclodextrin (β-CD and γ-CD) carriers with chitosan (CS) nanoparticles for targeted drug delivery and to compare their performance. The targeted drug delivery system includes the therapeutic agent of the CS nanoparticles targeting section of the same drug and the CD carrier s ...

20. Guaiane-type sesquiterpenoids from the roots of Stellera chamaejasme L. and their neuroprotective activities

Author:
Zhuo-Yang Cheng; Zi-Lin Hou; Jing-Xian Ren; Ding-Ding Zhang; Bin Lin; Xiao-Xiao Huang; Shao-Jiang Song
Source:
Phytochemistry 2021 v.183 pp. 112628
ISSN:
0031-9422
Subject:
Stellera chamaejasme; X-ray diffraction; apoptosis; cell viability; cells; chemical structure; humans; neuroprotective effect; plant biochemistry; roots; sesquiterpenoids; spectral analysis; staining
Abstract:
... Nine undescribed guaiane-type sesquiterpenoids stelleraterpenoids A‒I, along with seven reported congeners, were isolated and identified from the 70% EtOH extract of the roots of Stellera chamaejasme L. Their chemical structures were elucidated on the basis of various spectral data. The relative configurations were determined by their NOESY spectra and comparison between their experimental and cal ...
DOI:
10.1016/j.phytochem.2020.112628