New Cytotoxic Cytochalasans from a Plant-Associated Fungus Chaetomium globosum kz-19

Four new cytochalasans, phychaetoglobins A–D (1–4), together with twelve known cytochalasans (5–16), were isolated from a mangrove-associated fungus Chaetomium globosum kz-19. The new structures were elucidated on the basis of extensive 1D and 2D NMR, HR ESIMS spectroscopic analyses, and electronic circular dichroism (ECD) calculations. The absolute configuration of 2 was established by application of Mosher’s method. Compounds 4–8 exhibited moderate cytotoxicities against A549 and HeLa cell lines with the IC50 values less than 20 μM.