Study On Antifungal And Anticancer Activities Of Endophytes From Plants

Study on antifungal and anticancer activities ofendophytes from plantsAbstractEndophytes constitute a large, special fungal group with abundant secondary metabolites, including insecticidal, antimicrobic and antitumor agents. They are important resources for new antimicrobic and anticancer drugs. It's reported here the isolation results of endophytes from Taxus fflairei, Cepha]otaxus fortune] and Torreya grandis; the screening results of antifungal and anticancer strains; as well as the primary study of antituznor agents from anticancer strain H18-036, which has high activity.One hundred and seventy-two strains of endophytic fungi were isolated from Taxus zz~irei, Cephalo taxus fortune] and Torreya grandis. The result of the antifungal assay shows that ninety strains of the fungi have antagonism against one or more botanic pathogenic fungi, such as Neurospora sp., Trichoderiz~ sp. and Fusarium sp. etc. The percentage of antifungal strains to tested strains are as follows:40% Cephalotaxus fortune], 54.2% Taxus mairei, 57. 1% Torreya grandis Thirty-five strains have high antifungal activities with their inhibition zone diameter beyond l5rrm. The active endophytes are identified as seventeen genera, most of which belong to Paeci]omyces and Fusarium etc.Using the method of MTT(Methyl Thiazolyltetrazolium), these endophytes were screened for anticancer strains in vitro. The result shows that twenty-five strains(about 14.5% of the total strains isolated) can inhibit the growth of KB or HL-60 cells significantly. 3. 3% of endophytic fungi isolated from Cephalotaxus fortune], 19. 6% from Taxus n~ire], and 8. 6% from Torreya grandis have cytotoxic activities. Seven strains have their ID~ beyond 1,000, which constitute about 4. 1% of the total strains tested. The active strainsobtained mostly belong to Paecilowyces and CephalosporiuzizAmong all the highly active anticancer strains, strain H18-036, which was identified as Paeci]~yces, can inhibit the growth of HL-60 and KB cells significantly. Its culture product was isolated and purified, and one crystal with other five pure components were obtained. TLC(Thin Layer Chromatography) test results show that the crystal has the same R~ value and coloring reactions with crystal Brefeldin A, which was obtained by direct extraction from culture medium of strain H18-036. Through TLC and coloring reactions, another five components were initially identified as alkaloid or ainidocyanogen agents, easy to be oxidized. At least three of them are found to highly inhibit the growth of HL~-60 cells with the method of MTI7, and their ID~are as follows: 800, >2,000, 800. They are worthy of further study.