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Extensive NMR (extensive + nmr)

Distribution by Scientific Domains
Chemistry75%

Terms modified by Extensive NMR

  • extensive nmr studies
    		•

    Selected Abstracts

    Acylated manoyl oxide diterpenes of Stemodia trifoliata

    MAGNETIC RESONANCE IN CHEMISTRY, Issue 6 2010
    Wildson Max B. da Silva
    Abstract Two new labdane diterpenes, 6,-malonyloxy-ethyl ester manoyl oxide and bis-6,-dioxymanoylmalonate, together with the known 6,-hydroxymanoyl oxide, 6,-malonyloxymaloyl oxide and betulinic acid were isolated from leaves of Stemodia trifoliata. Their structures were elucidated by spectroscopic studies (IR and HR-ESI-MS), including an extensive NMR (COSY, HSQC, HMBC and NOESY) analysis. Copyright © 2010 John Wiley & Sons, Ltd. [source]

    1H and 13C NMR spectral data of new saponins from Cordia piauhiensis

    MAGNETIC RESONANCE IN CHEMISTRY, Issue 8 2007
    Renata P. Santos
    Abstract Two new bidesmoside triterpenoid saponins were isolated from stems of Cordia piauhiensis. Their structures, characterized as 3- O -,- L -rhamnopyranosyl-(1 , 2)-,- D -glucopyranosyl pomolic acid 28- O -,- D -glucopyranosyl ester (1) and 3- O -,- L -rhamnopyranosyl-(1 , 2)-,- D -glucopyranosyl oleanolic acid 28- O -,- D -glucopyranosyl-(1 , 6)-,- D -glucopyranosyl ester (2), were unequivocally established after extensive NMR (1H, 13C, DEPT 135 , COSY, HSQC, HMBC, TOCSY, and NOESY) studies. Copyright © 2007 John Wiley & Sons, Ltd. [source]

    Withanolide sulfoxide from Aswagandha roots inhibits nuclear transcription factor-kappa-B, cyclooxygenase and tumor cell proliferation

    PHYTOTHERAPY RESEARCH, Issue 7 2009
    Vanisree Mulabagal
    Abstract Investigation of the methanol extract of Aswagandha (Withania somnifera) roots for bioactive constituents yielded a novel withanolide sulfoxide compound (1) along with a known withanolide dimer ashwagandhanolide (2) with an S-linkage. The structure of compound 1 was established by extensive NMR and MS experiments. Compound 1 was highly selective in inhibiting cyclooxygenase-2 (COX-2) enzyme by 60% at 100 µm with no activity against COX-1 enzyme. The IC50 values of compound 1 against human gastric (AGS), breast (MCF-7), central nervous system (SF-268) and colon (HCT-116) cancer cell lines were in the range 0.74,3.63 µm. Both S-containing dimeric withanolides, 1 and 2, completely suppressed TNF-induced NF- ,B activation when tested at 100 µm. The isolation of a withanolide sulfoxide from W. somnifera roots and its ability to inhibit COX-2 enzyme and to suppress human tumor cell proliferation are reported here for the first time. In addition, this is the first report on the abrogation of TNF-induced NF- ,B activation for compounds 1 and 2. Copyright © 2009 John Wiley & Sons, Ltd. [source]

    Cervimycin A,D: A Polyketide Glycoside Complex from a Cave Bacterium Can Defeat Vancomycin Resistance

    CHEMISTRY - A EUROPEAN JOURNAL, Issue 19 2005
    Kerstin Herold Dr.
    Abstract Cervimycins A,D are novel polyketide glycosides with significant activity against multi-drug-resistant staphylococci and vancomycin-resistant enterococci. They are produced by a strain of Streptomyces tendae, isolated from an ancient cave. The structures of the cervimycins were determined by performing extensive NMR and chemical degradation studies. All cervimycins have a common tetracyclic polyketide core that is substituted with unusual di- and tetrasaccharide chains, composed exclusively of trideoxysugars; however, they differ in the acetyl and carbamoyl ring substituent and in the highly unusual terminal methylmalonyl and dimethylmalonyl residues. [source]