Study On Screening And Bioactivity Secondary Metabolites Of Deep-sea Fungus Acaromyces Ingoldii

The conditions in deep-sea environments are a biologically competitive environment with unique conditions and can be characterized by high salt, alkaline, hypoxia, and oligotrophy, marine-derived fungi have proven to be a rich source of structurally unique and biologically active secondary metabolites in these environments. In recent years, lots of novel structures and compounds with remarkable activity was derived from marine microorganisms. People have been given attention as marine fungus to be a great part of marine microorganisms. In the course of searching for natural products with bioactive from the deep sea fungus Acaromyces ingoldii FS121 isolated from deep sea sediments in the south China sea, we found the fermentation extracted with ethyl acetate exhibited strong cytotoxic inhibitory potency against Hep G-2, SF-268, MCF-7, NCI-H460 cell lines at a concentration of 100 mg/m L, with inhibitory rate at 92.2%, 95.7%, 95.1% and 92.3%, respectively. On a large scale fermentation and separation, extraction with significant active compounds are expected.18 compounds were isolated from the fermentation extracts of deep-sea fungus Acaromyces ingoldii FS121 by silica gel column chromatography, RP-18 chromatography, Sephadex-LH20 column chromatography, HPLC, preparative TLC. Their structures were identified by extensive analysis of their spectroscopic data with spectroscopic methods including ESI-MS, HR-ESI-MS, 1H-NMR, 13C-NMR, DEPT, HMQC, HMBC, 1H-1H COSY, NOESY. These compounds were isolated and identified as 2 naphthoquinone pyrans, 4 steroids, an isocoumarin, a pyrimidine, a thiazole, an ethyl thiazole and 8 benzene derivatives. AF-10 and AF-12 are new compounds, the absoute configuration of AF-10 was established by synthesis its 1H-NMR coupling constants and CD spectra data reported in the literature. All these compounds were isolated from Acaromyces genus for the first time.All of the isolates were tested their cytototxic antifungal and antibacterial activity against MCF-7, NCI-H460, SF-268, Hep G-2 cell lines, Curvularia lunata, Cylindrocladium, Alternaria alternata, Colletotrichum gloeosporioides, Staphylococcus aureus, Escherichia coli and Bacillus subtilis by SRB and filter paper diffusion method, then the active compounds were further tested for their IC50。Compounds AF-6, AF-8, AF-9, AF-10 and AF-11 displayed strong cytototxic activities against MCF-7, NCI-H460, SF-268, Hep G-2 cell lines, furthermore, AF-10 and AF-11 showed strong cytototxic activities against all four cell lines with IC50 7.88, 6.73, 10.03, 7.34 mM and IC50 5.72, 4.10, 6.06, 5.72 mM, respectively. AF-10 and AF-11 also showed significant antibacterial activity against Bacillus subtilis with inhibition rate 52.63% and 42.10% at a concentration of 100 mg/m L.In conclusion, 18 compounds were isolated from the deep-sea fungus Acaromyces ingoldii FS121, 2 of them were identified as new compounds, 5 compounds were proved to have significant bioactivty. This research provides a scientific theoretical basis for the development of marine microorganism.