RRC ID 11520
Author Tayone WC, Honma M, Kanamaru S, Noguchi S, Tanaka K, Nehira T, Hashimoto M.
Title Stereochemical investigations of isochromenones and isobenzofuranones isolated from Leptosphaeria sp. KTC 727.
Journal J Nat Prod
Abstract Two new metabolites, (R)-3,4-dihydro-4,6,8-trihydroxy-4,5-dimethyl-3-methyleneisochromen-1-one (1) and (R)-7-hydroxy-3-((S)-1-hydroxyethyl)-5-methoxy-3,4-dimethylisobenzofuran-1(3H)-one (2), were isolated along with two structurally known related compounds (3 and 4) from the culture broth of Leptosphaeria sp. KTC 727 (JCM 13076 = MAFF 239586). These structures were disclosed mainly with (1)H and (13)C NMR spectroscopic analyses. The relative configuration of 2 was established by NOE studies. The absolute configuration of this molecule was determined by a combination of the modified Mosher's method and CD spectra after derivatizations. The theoretical CD profiles also supported these assignments. Structural correlations enabled us to establish the absolute configurations of metabolites 1, 3, and 4, in which configurations of the latter two had not been established. Compound 2 exhibited the strongest antifungal activity among them, inhibiting the hyphal growth of Cochliobolus miyabeanus at about 0.5 μg/mL.
Volume 74(3)
Pages 425-9
Published 2011-3-25
DOI 10.1021/np100838j
PMID 21265556
MeSH Antifungal Agents / chemistry Antifungal Agents / isolation & purification* Antifungal Agents / pharmacology Ascomycota / chemistry* Ascomycota / drug effects Benzofurans / chemistry Benzofurans / isolation & purification* Benzofurans / pharmacology Coumarins / chemistry Coumarins / isolation & purification* Coumarins / pharmacology Japan Microbial Sensitivity Tests Molecular Structure Nuclear Magnetic Resonance, Biomolecular Stereoisomerism
IF 3.782
Times Cited 33
General Microbes JCM 13076