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Mosher Method (mosher + method)

Distribution by Scientific Domains
Chemistry100%

Kinds of Mosher Method

  • modified mosher method
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    Selected Abstracts

    Trichocladinols A,C, Cytotoxic Metabolites from a Cordyceps -Colonizing Ascomycete Trichocladium opacum

    EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 32 2009
    Huijuan Guo
    Abstract Trichocladinols A,C (1,3), three new metabolites, and the known massarigenin A (4), have been isolated from cultures of a Cordyceps -colonizing ascomycete Trichocladium opacum. Their structures were elucidated by NMR spectroscopy and X-ray crystallography. The absolute configuration of 1 was assigned by using the modified Mosher method and that of 3 was determined by X-ray crystallographic analysis of its (S)-MTPA ester. Compounds 1,3 showed modest cytotoxic effects against the human tumor cell lines HeLa and MCF-7. Structurally, compounds 1 and 2 possess a previously undescribed 2,9-dioxatricyclo[5.2.1.03,8]dec-4-ene skeleton.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) [source]

    Diarylheptanoids from the Rhizomes of Alpinia officinarum

    HELVETICA CHIMICA ACTA, Issue 1 2008
    Yi Sun
    Abstract A novel dimeric diarylheptanoid, (5R,5,R)-7,7,-(6,6,-dihydroxy-5,5,-dimethoxy[1,1,-biphenyl]-3,3,-diyl)bis[5-methoxy-1-phenylheptan-3-one] (1), and two new diarylheptanoids, (4E,6R)-6-hydroxy-7-(4-hydroxy-3-methoxyphenyl)-1-phenylhept-4-en-3-one (2) and (4E,6R)-6-hydroxy-1,7-diphenylhept-4-en-3-one (3), together with seven known diarylheptanoids, were isolated from the rhizomes of Alpinia officinarum. Their structures were elucidated by application of extensive spectroscopic analyses and the modified Mosher method. [source]

    The Absolute Configuration of (+)-Ethyl cis -1-Benzyl-3-hydroxypiperidine-4-carboxylate and (+)-4-Ethyl 1-Methyl cis -3-Hydroxypiperidine-1,4-dicarboxylate; a Revision

    HELVETICA CHIMICA ACTA, Issue 12 2006
    Piergiorgio
    Abstract Discrepancies between chiroptical data from the literature and our determination of the structure of the title compounds (+)- 5 and (+)- 9a were resolved by an unambiguous assignment of their absolute configuration. Accordingly, the dextrorotatory cis -3-hydroxy esters have (3R,4R)- and the laevorotatory enantiomers (3S,4S)-configuration. The final evidences were demonstrated on both enantiomers (+)- and (,)- 5 by biological reduction of 4 by bakers' yeast and stereoselective [RuII(binap)]-catalyzed hydrogenations of 4 (Scheme,2), by the application of the NMR Mosher method on (+)- and (,)- 5 (Scheme,3), as well as by the transformation of (+)- 5 into a common derivative and chiroptical correlation (Scheme,4). [source]

    Two Novel 14-Nor-13,14-secopodocarpanes from the Bark of Taiwania cryptomeriodes

    HELVETICA CHIMICA ACTA, Issue 2 2004
    Shih-Chang Chien
    The two novel compounds cryptomelactones A (3) and B (4) were isolated from the bark of Taiwania cryptomeriodes, besides the two known podocarpane derivatives 1,,13,14-trihydroxypodocarpa-8,11,13-trien-7-one (1) and 3,,13,14-trihydroxypodocarpa-8,11,13-trien-7-one (2), and were characterized by spectroscopic means including 2D-NMR techniques. Compounds 3 and 4 are novel-14-nor-13,14-seco-podocarpanes. The absolute configurations of 3 and 4 were determined by the modified Mosher method. The biotransformation mechanism of 3 and 4 is proposed. [source]

    Chondrochloren A and B, New ,-Amino Styrenes from Chondromyces crocatus (Myxobacteria)

    EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 14 2003
    Rolf Jansen
    Abstract In a screening for biologically active metabolites of the genus Chondromyces, two novel metabolites, chondrochloren A (1) and B (2), were isolated from several strains of C. crocatus. Compounds 1 and 2 are unique chloro-hydroxy-styryl amides of a highly modified C14 carboxylic acid, which comprises an unsaturated ketone, two hydroxy, two methoxy and three methyl groups. After assignment of the absolute configuration of both carbinol stereocenters by Mosher's method, NMR spectroscopic data combined with MM2 calculations allowed the prediction of the preferred conformation in solution. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003) [source]

    Biosynthesis of the Myxobacterial Antibiotic Corallopyronin A

    CHEMBIOCHEM, Issue 9 2010
    Özlem Erol
    Abstract Corallopyronin A is a myxobacterial compound with potent antibacterial activity. Feeding experiments with labelled precursors resulted in the deduction of all biosynthetic building blocks for corallopyronin A and revealed an unusual feature of this metabolite: its biosynthesis from two chains, one solely PKS-derived and the other NRPS/PKS-derived. The starter molecule is believed to be carbonic acid or its monomethyl ester. The putative corallopyronin A biosynthetic gene cluster is a trans-AT-type mixed PKS/NRPS gene cluster, containing a ,-branching cassette. Striking features of this gene cluster are a NRPS-like adenylation domain that is part of a PKS-type module and is believed to be responsible for glycine incorporation, as well as split modules with individual domains occurring on different genes. It is suggested that CorB is a trans-acting ketosynthase and it is proposed that it catalyses the Claisen condensation responsible for the interconnection of the two chains. Additionally, the stereochemistry of corallopyronin A was deduced by a combination of a modified Mosher's method and ozonolysis with subsequent chiral GC analyses. [source]

    Chemical Characterization of New Oxylipins from Cestrum parqui, and Their Effects on Seed Germination and Early Seedling Growth

    CHEMISTRY & BIODIVERSITY, Issue 9 2008
    Antonio Fiorentino
    Abstract Isolation, chemical characterization, and phytotoxicity of five new oxylipins, together with seven already known related compounds, from Cestrum parqui L',Hérl. is reported. All the structures were elucidated on the basis of their spectral data, especially 1D- (1H- and 13C-NMR, DEPT) and 2D-NMR (COSY, TOCSY, HSQC, HMBC, and NOESY). The configurations of the stereogenic C-atoms were determined by the Mosher's method. The compounds have been assayed for their phytotoxicity on Lactuca sativa at concentrations ranging between 10,4 and 10,8,M. The results of the phytotoxicity tests on the germination and growth of the test species, obtained by a cluster analysis, showed interesting relationship between the chemical structures of the compounds and their biological effects. [source]