Studies On Secondary Metabolites Of Three Marine-derived Fungus And Their Bioactivities

Due to the unique living conditions, marine-derived fungi possess unique andrich variety of biosynthetic pathway in the long-term of the natural selection, thus thesecondary metabolites of them have the novelty of the skeletons and diversity ofbiological activity, and have been discovered as an important source for leadcompounds.61fungal strains were isolated from13sponge samples from the South ChinaSea. By antitumor bioassay screening,17active strains were chosen. Combined withTLC and HPLC, chemical analyses were performed for the active secondarycompounds of these17strains, and2fungi of MXH-99（Metarhizium anisopliae）andKXL-157（Apiospora montaqnei）were selected for further study. What’s more, thesecondary metabolites of the fungus GWQ-143（Penicillium solitum）isolated byprevious work were also studied.Nine new compounds, including two naphtho-γ-pyrones glycosides、 twolactones、two benzamides、two meroterpenoids and one hexaketide, as well as twonew natural products (benzamides), together with17known ones were isolated fromthe EtOAC extracts of the fermentations from three target strains, MXH-99、GWQ-143and KXL-157, chromatographed by repeated TLC, silica gel column,Sephadex LH-20and semi-preparative HPLC. Their structures were established onthe basis of chemical and spectroscopic evidence.The abilities of1-8to inhibit the growth of M. phlei were measured by the filterpaper disk diffusion method, the known isochaetochromin B2(6) and ustilaginoidin D(7) exhibited the highest activity with MICs50μg/mL; the antitumor activities againstseveral cancer cell lines of these compounds were assayed with the results that onlycompound23-25showed week cytotoxicity. The inhibition rates of compound24(ata concentration of50μM) against P388and A549cell lines were73.8%and51.9%,respectively; and compound23and25showed moderate inhibition rates of43.8% and36.6%against P388cell line at a concentration of25μM, respectively.In summary,28compounds including9new compounds and2new naturalproducts were isolate from the fermentations of three marine-derived fungi. Two ofthem (compounds6-7) exhibited the highest activity with MICs50μg/mL, three ofthem (compounds23-25) showed moderate cytotoxicity. A sponge-derived funguswith high output of griseofulvin was provided as important medicinal resource.