Bioactivity Of Endophytic Fungi From Polygonummultiflorum Thunb.and Their Secondary Metabolites

There has been more than100years since the endophytic fungi were explored by scientist. Studies involved endophytic fungi were beginning with the discovery of endophytic fungi from the seed of Lolium temulentum L. by Vogl in the year of1898. A large number of researches have been reported that endophytes isolated from medicinal plants are available to produce active metabolites. Endophytes also can synthesis a mass of materials which are similar in pharmaceutical use as their host paint does. In recent30years, serviceable secondary metabolites including paclitaxel, podophyllotoxin, shikonin, tanshinone, vincristine have been obtained from a series of medicinal plants. Accordingly, we choose Polygonum multiflorum Thunb., Chinese traditional medicinal plant, as goal plant to study the biological activity of endophytic fungi. Aspects involved isolation, purification and identification of endophytic fungi from Polygonum multiflorum Thunb., exploring biological activity as antioxidant, atherosclerosis prevension and antifungal of endophytic fungi fermentation and chemical analysis of active fungus’secondary metabolites. Results are explained as follows:(1) Isolation, Purification and Identification of Edophytic FungiIn our present study,86isolates were isolated from Polygonum multiflorum Thunb. obtained from Sichuan province, Guangdong province and Shanghai. By means of phylogenetic analysis and similarity comparison of ITS sequences,86isolates were identified into14taxa, including9species (Xylariaceae, Mytilinidiaceae, Helotiaceae, Tuberaceae, Otideaceae, Pezizaceae, Ascobolaceae, Discinaceae, Clavicipitaceae) of25genera (Fusarium, Lasiodiplodia, Trichaptum, Cochliobolus, Bipolaris, Bjerkandera, Curvularia, Talaromyces, Cladosporium, Penicillium, Chaunopycnis, Xylariaceae, Xylaria, Nemania, Sordariomycetes, Creosphaeria, Myrothecium, Colletotrichum, Alternaria, Phoma, Trametes, Botryotinia, Exserohilum, Botryosphaeria, Fusarium) and37taxa placed above family level. Fusarium sp. whose isolation rates were17.2%and16.8%apparently was recognized as the dominate species both in Shanghai and Sichuan. Whereas, Alternariasp. whose isolation was18.87%was the dominate species in Guangdong.(2) Study on Biological Activity of Endophytic FungiScreening target fungus producing stilbenes or anthraquinones, anti-tumor and antifungal activity Pyricularia oryzae P-2b model of endophytes fermentation and chemical analysis of active fungus’metabolites were discussed in this paper. Employing the method of HPLC,8fungi were presumed to produce stilbenes and1fungus was presumed to synthesis anthraquinones. By the further dection of LC-MS, there was no fungus producing stilbenes or anthraquinones.There were32fungi showing activity of anti-tumor and antifungal by the means of Pyricularia oryzae P-2b model,71.1%of all the fungi isolated from Polygonum multiflorum Thunb..2fungi (HSW-31KJ475831Fusarium oxysporum, HSW-45K5415845Penicillium herquei) showed better activity of anti-tumor and antifungal, which can be taken into further study involving evaluation of their activity in vivo or in vitro.The results implied endophytic fungi from Polygonum multiflorum Thunb.were supposed as new bioresource of anti-tumor and antifungal drug.In the study of judging the anti-atherosclerosis effect of Polygonum multiflorum Thunb.root methanol extract and endophytic fungi methanol extract,40%of fungi and Polygonum multiflorum Thunb.root methanol extract can effectively inhibit the formation of foam cells compared with simvastatin. The inhibition rates of HSW-18(KJ475818Fusarium chlamydosporumi) and HSW-25(KJ475825Creosphaeria sp.) were both more than25%. Other fungi as HSW-2(KJ475802Lasiodiplodia pseudotheobromae), HSW-31(KJ475831Fusarium oxysporum) and HSW-39(KT475839Phoma herbarum) also exhibited good activity of inhibiting foam cells formation. According to these results, compounds existed in Polygonum multiflorum Thunb. and its endophytic fungi can be used as drugs for atherosclerosis prophylaxis.Through the experiment of measuring antioxidative activity of Polygonum multiflorum Thunb. root and endophytes, we found that HSW-5(KJ475805Cochliobolus australiensis), HSW-23(KJ475823Fusarium chlamydosporumi) and HSW-25(KJ475825Creosphaeria sp.) had significant DPPH and O2-scavenging, which could be the possible explanation of their significant inhibition in foam cells formation. Whereas, the results showed that HSW-31(KJ475831Fusarium oxysporum) and HSW-39(KT475839Phoma herbarum) had a low antioxidative effect. We deemed that there may be another activity compounds not relevant with antioxidant in HSW-31(KJ475831Fusarium oxysporum) and HSW-39(KT475839Phoma herbarum) could depress the process of foam cells formation. Methanol extract of Polygonum multiflorum Thunb. root also showed ideal antioxidative effect.(3) Isolation and Chemical Analysis of HSW-31(KJ475831Fusarium oxysporum) Secondary MetaboliteBecause HSW-31(KJ475831Fusarium oxysporum) exhibited good activity in anti-tumor, antifungal and suppressing foam cells formation observably, we considered it as goal fungus to isolate its secondary metaboltes. After fermanting HSW-31(KJ475831Fusarium oxysporum) in large-scale, compounds involved in the crude acetoacetate extract were isolated and analyzed.7compounds were isolated,5of which were investigated as ergosterol. Qualification of the others is in progress.