The isolation and structural elucidation of a new iridoid glycoside from Cymbaria dahurica L.

2018 ◽  
Vol 73 (6) ◽  
pp. 377-379 ◽  
Author(s):  
Cui-Lan Bai ◽  
Qing-Hu Wang ◽  
Yan-Hua Xu ◽  
Jun-Sheng Han ◽  
Yin-Ping Bao
Keyword(s):  
Quantum Coherence ◽  
Nuclear Overhauser Effect ◽  
Multiple Bond ◽  
2D Nmr ◽  
Iridoid Glycoside ◽  
Correlation Spectroscopy ◽  
Etoac Extract ◽  
Overhauser Effect ◽  
Nuclear Overhauser ◽  
C Nmr

AbstractA new iridoid glycoside, namely, cymdahoside A (1), together with two known ones, 2 and 3, were isolated from the EtOAc extract of Cymbaria dahurica. The structure elucidation of 1 was carried out by one-dimensional (1D) NMR (1H and 13C NMR) and 2D NMR (correlation spectroscopy, heteronuclear single-quantum coherence, heteronuclear multiple-bond correlation and nuclear Overhauser effect spectroscopy) spectral analyses.

Sesquiterpenes from the Saudi Red Sea: Litophyton arboreum with their cytotoxic and antimicrobial activities

2018 ◽  
Vol 73 (1-2) ◽  
pp. 9-14 ◽  
Author(s):  
Lamia T. Abou El-Kassem ◽  
Usama W. Hawas ◽  
Samy K. El-Desouky ◽  
Radwan Al-Farawati
Keyword(s):  
Red Sea ◽  
Quantum Coherence ◽  
Nuclear Overhauser Effect ◽  
Multiple Bond ◽  
Cancer Cell Line ◽  
2D Nmr ◽  
Antimicrobial Activities ◽  
Correlation Spectroscopy ◽  
Coherence Spectroscopy ◽  
Nuclear Overhauser

AbstractA new pseudoguaiane-type sesquiterpene named litopharbol (1) was isolated from the methanolic extract of the Red Sea soft coralLitophyton arboreum, along with known sesquiterpenoids alismol (2), alismorientol B (3), teuhetenone A (4), and calamusin I (5); steroid, 24-methyl-cholesta-5,24(28)-diene-3β-ol (6), alkyl glyceryl ether, chimyl alcohol (7); sphingolipid, erythro-N-dodecanoyl-docosasphinga-(4E,8E)-dienine (8); and nitrogenous bases, thymine (9) and thymidine (10). The structures were determined on the basis of nuclear magnetic resonance (NMR) spectroscopic (1D and 2D NMR data including heteronuclear single quantum coherence spectroscopy, heteronuclear multiple-bond correlation spectroscopy, and nuclear Overhauser effect spectroscopy) and mass spectrometric analyses. Compounds1–5were explored for antimicrobial activity and cancer cell line sensitivity tests. Compound1exhibited antibacterial activity againstBacillus cereuswith a minimum inhibition concentration of 1.8 μg/mL, whereas compound3showed significant potent cytotoxic effect against MCF-7 (breast cancer cells) with IC504.32 μM.

Unusual pyranosyl cembranoid diterpene from Sarcophyton trocheliophorum

2016 ◽  
Vol 71 (12) ◽  
pp. 1211-1217 ◽  
Author(s):  
Mohamed Shaaban ◽  
Mohamed A. Ghani ◽  
Khaled A. Shaaban
Keyword(s):  
Quantum Coherence ◽  
Soft Coral ◽  
High Resolution Mass Spectrometry ◽  
Nuclear Overhauser Effect ◽  
Multiple Bond ◽  
2D Nmr ◽  
Correlation Spectroscopy ◽  
Multiple Quantum ◽  
Chemical Structures ◽  
Sarcophyton Trocheliophorum

Abstract9-Hydroxy-10,11-dehydro-sarcotrocheliol (1), a new pyrane-based cembranoid diterpene, has been isolated along with three other known compounds, namely, sarcotrocheliol acetate (2), (+)-sarcophytol A (3), and (−)-sarcophytonin A (4), from the organic extract of the soft coral Sarcophyton trocheliophorum. The chemical structures of compounds 1–4 were determined on the basis of their 1D and 2D NMR [1H, 13C, 1H–1H correlation spectroscopy, heteronuclear multiple-quantum coherence, heteronuclear multiple-bond correlation, and nuclear Overhauser effect (NOE)] and mass spectra [electron ionization (EI), electrospray ionization, and high resolution mass spectrometry (HRMS)], and by comparison with related structures. The compounds 1–4 showed neither antimicrobial activity against 11 diverse tested microorganisms, nor cytotoxicity against brine shrimp, whereas the soft coral extract showed low cytotoxicity with a mortality rate of 1.7%.

Two-dimensional NMR studies of acrylate copolymers

2009 ◽  
Vol 81 (3) ◽  
pp. 389-415 ◽  
Author(s):  
A. S. Brar ◽  
Ashok Kumar Goyal ◽  
Sunita Hooda
Keyword(s):  
Methyl Methacrylate ◽  
Methyl Acrylate ◽  
Quantum Coherence ◽  
Multiple Bond ◽  
Microstructural Analysis ◽  
2D Nmr ◽  
Correlation Spectroscopy ◽  
Nmr Studies ◽  
Poly Methyl Methacrylate ◽  
Nmr Study

High-resolution NMR spectroscopy is the most versatile, reliable, and generally acceptable technique for the determination of the microstructure of polymers. 2D NMR techniques, along with 1D NMR, have more potential to study absolute configurational assignments and sequence distribution of copolymers. Physical and chemical properties of polymers are influenced fundamentally by their microstructure. We discuss the detailed microstructure analysis of a large number of homopolymers, copolymers, and terpolymers. 2D NMR study of poly(methyl methacrylate) (PMMA), poly(methyl acrylate) (PMA), and poly(methacrylonitrile) (PMAN) is discussed in this article. In addition to homopolymers, 2D heteronuclear single-quantum coherence (HSQC), total correlation spectroscopy (TOCSY), and heteronuclear multiple-bond correlation (HMBC) study of different copolymers such as poly(methyl methacrylate-co-methyl acrylate), poly(styrene-co-methyl methacrylate), and poly(methyl methacrylate-co-methacrylonitrile) have also been reported here. This in turn helps in microstructural analysis of terpolymers such as poly(methacrylonitrile-co-styrene-co-methyl methacrylate), poly(acrylonitrile-co-methyl methacrylate-co-methyl acrylate), and poly(ethylene-co-vinyl acetate-co-carbon monoxide).

scholarly journals Benderamide A, a Cyclic Depsipeptide from a Singapore Collection of Marine Cyanobacterium cf. Lyngbya sp.

Marine Drugs ◽  
2018 ◽  
Vol 16 (11) ◽  
pp. 409 ◽  
Author(s):  
Chi Ding ◽  
Ji Ong ◽  
Hui Goh ◽  
Cynthia Coffill ◽  
Lik Tan
Keyword(s):  
Breast Cancer Cells ◽  
Nuclear Overhauser Effect ◽  
2D Nmr ◽  
Marine Cyanobacterium ◽  
One Dimensional ◽  
Mechanistic Pathway ◽  
Overhauser Effect ◽  
Cyclic Depsipeptide ◽  
Nuclear Overhauser ◽  
Related Compounds

Benderamide A (1), a (S)-2,2-dimethyl-3-hydroxy-7-octynoic acid (S-Dhoya)-containing cyclic depsipeptide that belongs to the kulolide superfamily, was isolated from a Singapore collection of cf. Lyngbya sp. marine cyanobacterium using a bioassay-guided approach. While the planar structure of 1 was elucidated using a combination of 1D and 2D NMR experiments and MS analysis, the absolute configuration was subsequently achieved using the results obtained from Marfey’s analysis, comparative analysis of nuclear overhauser effect spectroscopy (NOESY) with the known compound 3, and one dimensional-nuclear overhauser effect (1D-NOE). Although 1 did not display antiproliferative activity against MCF7 breast cancer cells, the presence of an Ala instead of Gly suggests a possible mechanistic pathway to explain the consequential decrease in cytotoxicity compared to the closely related 2. In addition, results obtained from an LC–MS/MS-based molecular networking algorithm revealed two other closely related compounds encouraging further identification and isolation from the same marine cyanobacterium extract.

Revised structure of a delta-aminolevulinic acid derivative

1993 ◽  
Vol 39 (9) ◽  
pp. 1867-1871 ◽  
Author(s):  
M Kajiwara ◽  
K Hara ◽  
K Takatori ◽  
K Matsumoto
Keyword(s):  
Aminolevulinic Acid ◽  
Nuclear Overhauser Effect ◽  
Correlation Spectroscopy ◽  
Molecular Formula ◽  
X Ray ◽  
Overhauser Effect ◽  
13C Nuclear Magnetic Resonance ◽  
Relative Arrangement ◽  
Effect Difference ◽  
Nuclear Overhauser

Abstract The structure of the fluorescent derivative formed in the method of Okayama et al. (Clin Chem 1990; 36:1494-7) for determining delta-aminolevulinic acid (ALA) concentrations was reinvestigated after esterification. The molecular ion peak at m/z 303.1473 corresponded to the molecular formula of C17H21NO4 (calcd 303.1470). The infrared spectrum showed the presence of carbonyl and carboxyl groups. This compound contained two acetyl groups, two methyl groups, and one methoxycarbonylethyl group, as revealed by 1H and 13C nuclear magnetic resonance and 13C-1H shift-correlated spectroscopy. Experiments with correlation spectroscopy via long-range coupling indicated that the main skeleton is 3H-pyrrolizine. The relative arrangement of functional groups was determined by means of nuclear Overhauser effect difference experiments. We were led to the conclusion that the methyl ester of the derivative is 2,6-diacetyl-1,5-dimethyl-7-(2-methoxycarbonylethyl)-3H-pyrrolizine. This structure was unequivocally confirmed by x-ray analysis; therefore, the structure of the derivative itself is 2,6-diacetyl-1,5-dimethyl-7-(2-carboxyethyl)-3H-pyrrolizine.

A norterpenoid and tripenoids from Commiphora mukul: isolation and biological activity

2017 ◽  
Vol 72 (1) ◽  
pp. 11-15 ◽  
Author(s):  
Najeeb Ur Rehman ◽  
Hidayat Hussain ◽  
Husain Yar Khan ◽  
René Csuk ◽  
Ghulam Abbas ◽  
...  
Keyword(s):  
Cancer Cells ◽  
Quantum Coherence ◽  
Nuclear Overhauser Effect ◽  
Multiple Bond ◽  
Cancer Cell Line ◽  
Inhibitory Effect ◽  
Correlation Spectroscopy ◽  
Ionization Mass ◽  
Commiphora Mukul ◽  
Substantial Decline

AbstractBio-guided fractionation of the guggul gum resin of Commiphora mukul HOOK using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay for the breast cancer cell line MDA-MB-231 led to the isolation of a new C17 norditerpene named myrrhanone C (1) along with two known polypodane-type triterpenes, namely, myrrhanone B (2) and myrrhanol B (3). The structures of the isolated compounds were elucidated by means of 1D (1H and 13C) and 2D (correlation spectroscopy, heteronuclear single-quantum coherence, heteronuclear multiple-bond correlation, and nuclear Overhauser effect spectroscopy) NMR spectroscopy as well as mass (electrospray ionization-mass spectroscopy) spectral analyses. Interestingly myrrhanone C (1) was able to induce a substantial decline in cell proliferation. It reduced the viability of cancer cells by almost 81% and 87% at concentrations of 50 and 100 μg mL−1, respectively. Myrrhanone B (2) and myrrhanol B (3) showed a concentration-dependent growth inhibitory effect on cancer cells, with the latter being slightly more cytotoxic than the former at both the concentrations tested. Furthermore, myrrhanone C (1) and myrrhanone B (2) showed good α-glucosidase and urease inhibition.

scholarly journals One New Royleanumoate fromTeucrium royleanumWall. ex Benth

2014 ◽  
Vol 2014 ◽  
pp. 1-3
Author(s):  
Shabir Ahmad ◽  
Riaz Ullah ◽  
Naser M. AbdElsalam ◽  
Hassan Fouad ◽  
Ahtaram Bibi ◽  
...  
Keyword(s):  
Structure Elucidation ◽  
Quantum Coherence ◽  
Multiple Bond ◽  
2D Nmr ◽  
Correlation Spectroscopy ◽  
Multiple Quantum ◽  
Heteronuclear Multiple Bond Correlation ◽  
Heteronuclear Multiple Quantum Coherence ◽  
Nmr Techniques ◽  
Multiple Quantum Coherence

One new royleanumoate, a benzene ester (1), has been isolated fromT. royleanumWall. ex Benth along with two known compounds, namely, 3,4-dihydroxymethyl benzoate (2) and oleanolic acid (3). The structure elucidation of the isolated compounds was established on two-dimensional (2D) NMR techniques including heteronuclear multiple bond correlation (HMBC), heteronuclear multiple quantum Coherence (HMQC), and correlation spectroscopy (COSY) experiment.

Nepetolide: A New Diterpene from Nepeta suavis

2008 ◽  
Vol 63 (5) ◽  
pp. 591-594 ◽  
Author(s):  
Javid Hussain ◽  
Farman Ullah ◽  
Hidayat Hussain ◽  
Tasleem Hussain ◽  
M. Raza Shah
Keyword(s):  
Structure Elucidation ◽  
Quantum Coherence ◽  
Multiple Bond ◽  
2D Nmr ◽  
Correlation Spectroscopy ◽  
Multiple Quantum ◽  
Heteronuclear Multiple Bond Correlation ◽  
Heteronuclear Multiple Quantum Coherence ◽  
Nmr Techniques ◽  
Multiple Quantum Coherence

A new tricyclic clerodane-type diterpene, nepetolide (1), has been isolated from Nepeta suavis along with three known compounds namely β -sitosterol, stigmasterol, and ursolic acid. The structure elucidation of the isolated compounds was based primarily on two-dimensional (2D)-NMR techniques including correlation spectroscopy (COSY), heteronuclear multiple quantum coherence (HMQC), and heteronuclear multiple bond correlation (HMBC) experiments.

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