Study on the secondary metabolites and their bioactivities from the Acanthus ilicifolius derived fungi Trichoderma sp.RSF-1
Objective To study the chemical constituents and bioactivities of Acanthus ilicifolius-derived fungi Trichoderma sp.RSF-1 collected from Zhangjiangkou mangrove national nature reserve.Methods The isolation and purification of these compounds were performed by silica gel column chromatography,gel column chromatography and high performance liquid chromatography(HPLC).Their structures were characterized by analysis of NMR,MS and ORD,etc.The cytotoxicity and antibacterial activity of these pure compounds were tested.Results Thirteen compounds were isolated from the Acanthus ilicifolius-derived fungi Trichoderma sp.RSF-1,including one butyrolactone 1,five polyketides 2-6,one alkaloid 7,two sesterterpenes 8 and 9,three steroids 10-12 and one fatty acid 13.And their structures were identified as piterrione Ⅰ(1),nafuredin(2),penicilloxalone A(3),5-hydroxy-3-hydroxymethyl-2-methyl-7-methoxychromone(4),5-hydroxy-7-methoxy-2,3-dimethyl-4H-chromen-4-one(5),fusarimone A(6),(3R,6R)-4-methyl-6-(1-methylethyl)-3-phenylmethylperhydro-1,4-oxazine-2,5-dione(7),fusaproliferin(8),terpestacin(9),ergosterol(10),β-sitosterol(11),cerevisterol(12)and linoleic acid(13).Conclusion Thirteen compounds were isolated from Acanthus ilicifolius-derived fungi Trichoderma sp.RSF-1 collected from Zhangjiangkou mangrove national nature reserve.Compound 1 was a new compound,and compounds 7,8 and 9 were firstly isolated from the Trichoderma genus.Compound 7 displayed obvious cytotoxicity against a variety of cancer cell lines while compound 8 exhibited moderate cytotoxicity.Meanwhile,compounds 7 and 13 exhibited strong antibacterial activities against multiple pathogenic bacteria including Bacillus subtilis MRSA AT33591,Aeromonas salmonicida AS42,Vibrio anguillarum HUB 185 with the MIC values of 6.25-50.00 μg/mL.