Fibrinolytic Evaluation of Compounds Isolated from a Marine Fungus Stachybotrys longispora FG216

As a part of our continuing work to discover bioactive leading molecules from marine microorganism, ethyl acetate fraction of organic extract of the train Stachybotrys longispora FG216 showed fibrinolytic activity in our primary screen. The bioassay-guided purification of the active fractions resulted in isolation of a new isoindolone, FGFC2 (1) (FGFC2, Fungi fibrinolytic compound 2), together with two known compounds, LL-Z1272 beta (2) and ergosterol (3). The structure of compound 1 was elucidated by the spectral analysis of 1D (H-1, C-13) NMR, 2D (COSY, HSQC, and HMBC) and ESI-MS. Three compounds were evaluated for fibrinolytic activities in vitro. Compared to FGFC1 (EC50 = 47 mu mol/L) as a reference drug, compound 1 and ergosterol (3) showed moderate fibrinolytic activities in vitro with EC50 values of 108.16 and 156.30 mu mol/L, respectively. LL-Z1272 beta (2) had no fibrinolytic activity.