Cytotoxic cytochalasins from the endozoic fungus Phoma sp of the giant jellyfish Nemopilema nomurai

Four new cytochalasin derivatives (1-4), together with cytochalasin B (5), were isolated from the fungus Phoma sp. obtained from the giant jellyfish Nemopilema nomurai. The planar structure and relative stereo-chemistry were established by analysis of 1D and 2D NMR data. The absolute configuration was defined by the modified Mosher's method. The compounds showed significant cytotoxicity against a small panel of human solid tumor cell lines (A549, SK-OV-3, SK-MEL-2, XF 498, and HCT15) with IC50 values in the range of 0.5-30 mu M. The cytochalasin B (5) showed obvious cytotoxicity with IC50 of 7.9 mu M against HeLa human cervical carcinoma cells. (C) 2012 Elsevier Ltd. All rights reserved.