Identification and Fibrinolytic Evaluation of an Isoindolone Derivative Isolated from a Rare Marine Fungus Stachybotrys longispora FG216

An isoindolone derivative, Fungi fibrinolytic compound ( R )‐2,5‐bis((2 R ,3 R )‐2‐(( E )‐4,8‐dimethylnona‐3,7‐dien‐1‐yl)‐3,5‐dihydroxy‐2‐methyl‐7‐oxo‐3,4,7,9‐tetrahydropyrano[2,3‐ e ]isoindol‐8(2 H )‐yl)pentanoic acid (FGFC1, Fungi fibrinolytic compound 1 ), was isolated from a rare marine microorganism strain Stachybotrys longispora FG216. The structure of FGFC1 was elucidated by 1 H NMR, 13 C NMR, IR, and MS data; moreover, it was also evaluated for fibrinolytic activity in vitro and in vivo . The results showed that 0.1–0.4 mmol/L of FGFC1 could stimulate generation of plasmin activity (increased by 2.05–11.44 folds) by measuring Glu‐plasminogen and Lys‐plasminogen activation in vitro . The experiment of fluorescein isothiocyanate (FITC)‐fibrinogen degradation indicated that the effect of FGFC1 on fibrinolytic activity was mediated by plasminogen and scuPA. In addition, FGFC1 (10 mg/kg) could dissolve most of pulmonary thrombus of Wistar rat in vivo . It is possible that FGFC1 is a potential thrombolytic agent in the future.