Four new ambuic acid derivatives (1-4), and four known derivatives (5-8), were isolated from the solid culture of a plant pathogenic fungus Pestalotiopsis neglecta. Their structures were elucidated by extensive NMR experiments. The absolute configuration of the C-16 secondary alcohol in 1 was deduced via the CD data of the in situ formed [Rh2(OCOCF3)4] complex with the acetonide derivative of 1.
View Article and Find Full Text PDFThe purpose of this study is to elucidate the bioactive components responsible for the the α-glucosidase inhibitory activity detected in the EtOAc extract of the mushroom Hydnellum concrescens. Two new p-terphenyl derivatives, concrescenins A (1) and B (2), in along with six known compounds thelephantins L (3), I (4), J (5), K (6), dihydroauran-tiacin dibenzoate (7), and curtisian A (8) were isolated from the fruiting bodies of H. concrescens.
View Article and Find Full Text PDFNine new isoprenylated depsides, sterenins E-M (1-9), as well as five known compounds (10-14), were isolated from the solid culture of Stereum hirsutum. The structures of the new compounds were elucidated by spectroscopic methods. Their inhibitory activities against yeast α-glucosidase were evaluated in vitro.
View Article and Find Full Text PDFTwo new species of Stemphylium (anamorphic Pleospora) are described on the basis of morphological characters and molecular phylogenetic analyses. Stemphylium phaseolina and S. variabilis were isolated respectively from diseased leaves of Phaseolus vulgaris L.
View Article and Find Full Text PDFA new species of Ulocladium was isolated from diseased leaves from two Cucumis sp. growing in Sinkiang and Gansu provinces of China. Conidia were isolated from necrotic leaves and used to establish single-spore pure cultures.
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