Bioorganic chemistry of host-specific toxins from microbes and self-defense substances from plants involved in host-parasite interactions

目的：在寄主植物和病原体的相互作用中，寄主植物产生针对微生物的自卫物质，而病原体有时会产生寄主选择性物质。我们的实验目的是：a)澄清HMT-和pm -毒素的构效关系。稻瘟病菌和高粱helminthosporum植物毒素的分离。b)水稻对油菜黄单胞菌（Xanthomonas campestris pv）白叶枯病的抗性机制研究。oryzae。c)从野生稻Oryza officinalis， W0002叶片中分离出抗稻瘟病的抗真菌物质。其它植物提取物中抗真菌物质的分离与鉴定。结果：a) i)合成了HMT-和pm -毒素相关的30多种化合物，并对其活性进行了比较。至少需要4个β -酮基来表达高活性，并且每个β -酮基之间的亚甲基功能间隔需要超过7个才能表达高活性。ii)从稻瘟病菌的固体培养物中分离并鉴定出两个新的吡啶醇相关化合物为植物毒素。b)从水稻非细菌性叶枯病抗性品种旗叶中分离到10种新型抗菌二萜，并对其结构进行了测定。GC-MS-SIM定量分析表明，米唑里酯可能具有抑制作用。c)从野生稻（Oryza officinalis W0002）健康叶片中分离鉴定出(-)-茉莉酸和12-羟基-9(Z)-十二烯酸和11-羟基-9(Z)-十一烯酸两种新型抗真菌脂肪酸。

Objective : In interactions between a host-plant and pathogen, a host-plant produces self-defense substances against microbes and a pathogen sometimes produces a host-selective substances. Objectives in our experiments were : a) Clarification of structure-activity relationships of HMT- and PM-toxins. Isolation of phytotoxins from Pyricularia oryzae and Helminthosporium sorghicola. b) Studies on resistant mechanism of rice plant against a bacterial leaf blight caused by Xanthomonas campestris pv. oryzae. c) Isolation of antifungal substances from leaves of wild rice, Oryza officinalis, W0002 which shows resistant against rice blast disease. Isolation and identification of antifungal substances from other plant extracts.Results : a) i) Above 30 compounds related to HMT- and PM-toxins were synthesized and compared their activity using a susceptible corn leaf. At least four beta-ketol groups are required to express high activity and also spacing methylene functions between each beta-ketol group required above seven for high activity. ii) Two novel pyriculol related compounds were isolated and identified as phytotoxins from the solid culture of Pyricularia oryzae. b) Ten novel antibacterial diterpenes were isolated from a flag leaf of abacterial leaf blight-resistant cultivar of rice plant and determined their structures. Quantitative analysis of oryzalides using GC-MS-SIM suggested that a role of oryzalides might be an inhibitin. c) (-)-jasmonic acid and two novel fatty acids, 12-hydroxy-9(Z)-dodecenoic acid and 11-hydroxy-9(Z)-undecenoic acid, were isolated and identified from healthy leaves of wild rice, Oryza officinalis W0002 as a antifungal substance.