Bioactive Metabolites from the Deep-Sea-Derived Fungus Diaporthe longicolla FS429.

The chemical investigation of a methanol extract of the deep-sea-derived fungusDiaporthe longicollaFS429 led to the isolation of two novel diterpenoids longidiacids A and B (1and2), two new polyketides (3and4), two new cytochalasin analogues longichalasins A and B (6and8) and three known analogues5,7,9. Their structures were elucidated through comprehensive spectroscopic analysis, while the absolute configurations were established by the comparison of the experimental and quantum chemical calculated ECD spectra. The structure of compound7was confirmed through X-ray diffraction for the first time. In the bioassays compound8exhibited antiproliferative effects against SF-268, with an IC(50)value of 16.44 mu M. Moreover, compounds1and8were detected to inhibit 35.4% and 53.5% of enzyme activity ofMycobacterium tuberculosisprotein tyrosine phosphatase B (MptpB) at a concentration of 50 mu M.