Secondary Metabolites And Their Activities Of Three Endophytic Fungi From Coastal Area

There were more than one million endophytic fungi in nature. Because of thedifferent kinds of plants or different living environments, the secondary metabolites ofendophytic fungi were extremely diversity. The statistical analyses showed that51%of the secondary metabolites obtained from endophytes had biologically activity,indicating that endophytes are important potential sources of exploitation for newnatural products. In recent years, endophytes are paid more and more attentions,especially living in unusual or specialized ecological niches such as ocean, saltern,alkaline, endophytes, etc, because of occurring special physiochemical and biologicalprocesses.245endophytic fungi obtained from17plants living in the area along the coastof Laizhou Bay in Dongying, China. By antitumor bioassay screening,27activestrains were chosen. Combined with TLC and HPLC, chemical analyses wereperformed for the active secondary compounds of these27strains, and3fungi ofSXH-65(Penicillium sp. SXH-65), SXH-63(Penicillium chrysogenum) and SXH-69(Emericella nidulans) were selected for further study.Applying various of extract and chromatography methods,35compounds including21(3of them are new compounds,1of them is new natural product) compoundsisolated from the organic extract of SXH-65,4compounds (2of them are new compounds) isolated from the strain SXH-63, and10compounds isolated from thestrain SXH-69, were obtained. The structure type included meroterpenoids,benzodiazepine alkaloids, pyrones, xanthones, benzene derivations, and so on.The cytotoxicities of meroterpenoids, pyrones and benzodiazepine alkaloids wereevaluated against Hela, HL-60, A549and K562cell lines and exhibiting weakcytotoxicities with IC50values ranged from24to60μM. And the benzodiazepinealkaloids had not antimicrobial activity against Proteus bacillus, Escherichia coli,Bacillus subtillis, Micrococcus tetragenus at600μg/mL. This is the first report fortheir cytotoxities and antimicrobial activity. Further study should be conducted to testthem for other bioactivities such as antiviral activity, to understand the truebiological/ecological role of these metabolites in the life cycle of the fungus.In summary,245endophytes were isolated from17coastal plant samples, and35compounds including5new compounds and1new natural products were obtainedfrom3strains. The study provided new compounds for nature product and useful todiscover new antitumor compounds.