Diaporchalasins A–E, New Cytochalasins from the Endophytic Fungus Diaporthe sp. BMX12 Isolated from Aquilaria sinensis

Abstract

Five new cytochalasins, diaporchalasins A−E (1−5), together with 14 known congeners (6−19) were isolated from the endophytic fungus Diaporthe sp. BMX12, which was isolated from the branches of Aquilaria sinensis. The structures of the new compounds were elucidated by extensive spectroscopic analyses including high‐resolution electron spray ionization mass spectrometry (HRESIMS) and nuclear magnetic resonance (NMR). Their absolute configurations were assigned by theoretical electronic circular dichroism (ECD) calculations. Compounds 11 and 12 featuring a keto carbonyl at C‐21 displayed cytotoxicity toward K562, BEL‐7402, SGC‐7901, A549, and HeLa cell lines with IC50 values ranging from 4.4 to 47.4 μM.