Metabolites Of Endophytic Fungi From Cephalotaxus Fortunei And Their Bioactive Activities

Endophytes are microorganisms such as fungi and bacteria (including actinomycete) that live inter-and/or intra-cellularly inside the healthy plant tissues causing asymptomatic infections for all or part of their life cycle. Endophytic fungi have been investigated to have anti-fungal, anti-tumor and anti-oxidation activities, and evolve with the plant. Research results in recent years show that endophytes can produce some metabolites same or similar to those from the host plant, and metabolites with the novel structure and specific bioactivity.In the study, Cephalotaxus fortunei were selected to isolate and identify their endophytic fungi, then screen the bioactive strains and specific metabolites of endophytic fungi in different areas. The main results are as follows:In the present study,160 isolates were isolated from the bark of Cephalotaxus fortunei from Jiande. By means of their morphological characteristics phylogenetic analysis and similarity comparison of ITS sequences,160 isolates were identified into 16 genera of 14 family. Then, based on the mircodilution method,20 sample endophytes were fast screened by Pyricularia oryzae P-2b model, and activities of endophytes against pathogenic fungi and tumor cells were tested. Thus,40.0% of endophytic fungi suppressed the activity of P. oryzae P-2b. And,5 colonies (25.0%) showed excellent antifungal activities against Candida albicans, Cryptococcus neoformans, Trichophyton rubrum and Aspergillus fumigatus while 4 colonies (20.0%) showed excellent antitumor activities against MKN45, LOVO, HepG2 and HL-60 tumor cells. Among the bioactive colonies, the antifungal activity of S361 (Trichoderma atroviride) is the best, as well as the antitumor activity of S261 (Penicillium sp.).Fermentation broth of S361 and S261 were respectively prepared for isolation of metabolites, and the antibiotic metabolites were extracted with EtOAc. Using silica gel and size exclusion chromatography,20 compounds were isolated from fermentation broth of S361, among them,15 compounds were elucidated based on spectroscopic methods,3 of them, trichodermanin A, trichoderiols A and B are new compounds; 11 compounds were isolated from fermentation broth of S261, among them,5 compounds were elucidated based on spectroscopic methods, all of them are known compounds.Activities of 3 new compounds against pathogenic fungi and tumor cells were tested. Thus, trichodermanin A showed excellent anti-fungal activities against Candida albicans and Cryptococcus neoformans; trichoderiols A showed excellent anti-fungal activities against Cryptococcus neoformans; trichoderiols B showed excellent anti-fungal activities against Cryptococcus neoformans and Trichophyton rubrum. All 3 compounds showed moderate activities against MKN45, LOVO, HepG2 and HL-60 tumor cells.In summary, we studied the isolation, identification and bioassay of endophytes from plant Cephalotaxus fortunei, the extraction and separation of their components, and their activities. Endophytes are a potential source of novel anti-microbe chemistry and biology to assist in helping solve not only human health, but plant and animal health problems also. Indeed, it showed that endophytie fungus was isolated from the bark of plant Cephalotaxus fortunei have a wide range of anti-fungal and anti-tumor activities. Our study is part of a wider project aimed at the possible exploitation of the endophytic fungi isolated from plant Cephalotaxus fortunei. Research on the endophytes not only brings vast social profits but also has realistic theoretic significance.