Thiazolo[5,4- b ]pyridine Alkaloid and Seven ar -Bisabol Sesquiterpenes Produced by the Endophytic Fungus Penicillium janthinellum .

We investigated the secondary metabolites present in Penicillium janthinellum MPT-25, an endophytic fungus isolated from Taxus wallichiana var. chinensis (Pilger) Florin. Chemical characterization of the solid cultured extract resulted in the isolation of 11 compounds, including eight previously undescribed metabolites: a thiazolo[5,4- b ]pyridine alkaloid, janthinedine A ( 1 ), and seven ar -bisabol sesquiterpenes, janthinepenes A-G ( 2-8 ). Their structures were elucidated by a combination of extensive spectroscopic methods, including single-crystal X-ray diffraction and ECD spectra. The antimicrobial activities of these compounds were evaluated against seven agricultural pathogenic fungi and eight clinically drug-resistant bacteria.