Rare isotachin-derived from the Dasymaschalon rostratum fungus Penicillium tanzanicum ZY-5.

Four rare isotachin-derived, isotachins E-H (1-4), together with two known biogenetically related isotachin derivatives (5 and 6) were isolated from the solid rice fermentation of a fungus Penicillium tanzanicum ZY-5 obtained from a medicinal plant Dasymaschalon rostratum collected from the Changjiang County, Hainan Province, China. Their structures were elucidated using comprehensive spectroscopic methods. The single-crystal X-ray diffraction of compound 5 was determined. Compounds 1-4 have a trans-3-(methylthio)-acrylic acid fragment, which are rare in nature. The inhibitory activities of all compounds against the nitric oxide (NO) production induced by lipopolysaccharide in mouse macrophage RAW 264.7 cells in vitro were evaluated.