Studies On The Secondary Metabolites Of Two Marine-derived Fungi

The ocean is a huge treasury of natural products. The number of the newcompounds isolated from marine resource is increasing year by year. Marine derivednatural products are charactered for their novelty skeletons and high rate of bioactivity.Due to the complex ecological environment of the ocean， marine-derivedmicroorganism have great variety and specificity of species and their metabolism.Marine-derived microorganism is one of the highlight of the natural products research.In this reaearch, we choose two marine-derived fungi to trace their active metabolites.Studies include isolation of microorganism from sponge and coral samples, screeningof cytotoxic strains, preliminary evaluation of active strains, isolation and structuralelucidation of the secondary metabolites.From ten sponge and coral samples collected from xisha island and weizhou islandin guangxi province,30fungi were isolated. These strains were evaluated for theircytotoxicities against mouse leukemia tumor cells (P-388) and combined withchemical screenings (such as TLC and HPLC). Finally,7fungi were found to showantitumor activities and furnished considerable chemical constituents. Among them,the fungal strain Alternaria sp. TZP-11, was selected as target strain for furtherresearch. In addition, a privous researched deep-sea derived fungus strain Penicilliumsp F23-2, which produced various of novel compounds, was selected to study thediversity of secondary metaboltes according to the OSMAC (one strain manycompouds) approach.By means of solvent extraction, silica gel column, TLC, MPLC, SephadexLH-20, HPLC, etc,23compounds were separated and purified from the extracts ofthe two aimed strains. Employeed by modern spectral analysis (UV, MS, NMR, andIR) and physico-chemical properties, the structures (see Fig.1) of21compounds wereelucidated，including3new compounds(1、19、20). Furthermore, the chemicalstructures of these compounds were relate to tricycloalternarenes (1-6), biphenyl (7-8), trichothecenes (9), steroid (10), benzene derivatives (11-13), alkaloids (14-17),burgiadione(18), ambuic acid (19、20).The cytotoxicities anti-inflammatory activities ofthe compouds (7-11) were evaluated. The known compounds (7、9、10) exhibitedcytotoxicities against P388cell line. Compounds (9,10) showed inhibitory activitiesagainst A-549cell line. Compound（s7、8、9）showed anti-inflammatory activities.TheIC50values were22.1μΜ,27.6μM and74.5nM respectively.Summarily, this work obtained6bioactive marine-derived microorganism, and23compounds (21of them were elucidated) from two marine-derived active fungi.Compouds (7、9、10) showed cytotoxicities and compouds (7、8、9) exhibitedanti-inflammatory activities.This study provides novel structure types for marinenatural product chemistry and bioactive template for exploring new antitumor andanti-inflammatory drugs.