Studies Oil The Deirvatives Synthesis And Antifungal Activity Of Biological Source Trichodermin On C-4,8Positions

Currently, the creation of a novel fungicide for lead compounds from natural products is a very effective way. This kind of fungicides represents high effective, broad-spectrum antifungal activity, unique mechanism of action, environment friendly, and not easy to produce resistance with novel structures. Strobilurin fungicides derived from natural product β-methoxyl acrylic ester, due to its high antibacterial activity has become the most active and potential products in the fungicide market, so far it has developed eight varieties. Pyrrole fungicides such as fludioxonil and fenpiclonil are derived from natural products pyrrolnitrin.Trichoderma is a very important series of plant endophytic fungi of bio-control bacteria. Its widely study attributed to the trichodermin, its major metabolite, which have broad-spectrum, high antibacterial activity. However, it has been restricted the used in biological control due to its cell toxicity. To study the metabolites of Trichoderma more meticulously, and the better use of Trichoderma, but also to seek a more excellent structural skeleton of biological pesticide, in this paper, we consider the Trichodermin, the metabolite of Trichoderma taxi sp. nov. from Taxus chinesis var. mairei aS the lead compound, according to the method of the active sub-structure connection, do a more comprehensive structural modification to Trichodermin and biological activity screening. In this thesis, we report the following results:1) The researches of Trichodermin in plant endophytic fungi were systematically reviewed, the biological control research and application of Trichoderma, as well as the structure and biological activity of Trichodermin were also investigated in detail.2)46derivatives of Trichodermin were synthesized by modifying the positions of the C4and C8. All the compounds were confirmed by1H NMR and MS, some title compounds were also detected by13C NMR.3) According to "Stand operation process of testing pesticidal bioactivity", a series of novel compounds with good antifungal activities were obtained:at50ug mL-1, compound3b-1represents a significantly higher activity than lead compound Trichodermin in inhibiting Blumeria graminis, and the inhibition rate reached90.0%, and the inhibition rate of compound3b-2is85.0%, which is approximate to Trichodermin. The antifungal activities of compounds3b-4、3b-10and3b-12against Sclerotinia scleotiorum, were81.5%,87.3%and86.6%, respectively, slightly lower than the lead compound Trichodermin, which had95.5%inhibition rate. The antifungal activities of compounds3a-4、3b-5、3b-10and3c-4against Borrytis cinerea, were72.5%,71.0%,81.1%and74.3%, respectively. Although lower than the bactericidal activity of Trichodermin, higher than the commercialization of Scala(60%).The further preliminary screening to four compounds with high antifungal activities showed that:Compounds3b-10and3b-12represented high bacteriostatic activities against Sclerotinia scleotiorum even under a very low concentration, the inhibitory rate are64.2%and72.5%, respectively. Compound3b-1also displayed well antifungal activities against Blumeria graminis (75.0%). However, the antifungal activity of compound3a-8against Rhizoctonia solani was unsatisfied under low concentration.