Bioorganic chemistry of infection-inducing substances produced by phytopathogenic fungi.

目的微生物对植物的致病作用往往具有高度的宿主特异性。在许多情况下，这种特定作用的模式没有化学和生物学基础，但有些情况归因于微生物产生宿主决定因素（感染诱导物质），如宿主特异性有毒产物（HST）。目前拟开展的研究课题是：a)分别引起丹参褐斑病和燕麦维多利亚枯萎病的a . citri和H. victoriae真菌产生的actg -毒素和hv -毒素相关成分的分离和结构测定；b)丹参病或分别由H. maydis、T小种和Phyllosticta maydis真菌产生的HMT-和pm -毒素的结构-生物活性关系研究。c)为从真菌中分离出新的侵染诱导物质（已知产生HST的真菌如P. oryzae和H. maydis, o .）进行培养条件和生物测定方法的初步检验。结果a)从真菌中分离出2个较小的actg毒素相关化合物（actg毒素G和H）和一个新的倍半萜类化合物双氢孢原AO-1，并确定了它们的结构。hv -毒素M的结构被确定为一种新的victorin C相关化合物，hv -毒素H与victorin C同源，其他次要成分的分离正在进行中。b)系统合成了39个HMT-和pm -毒素模拟物。两种毒素的生物活性比较表明，HMT-和pm -毒素的生物活性构象是一定的循环形式。c)对P. oryzae和H. maydis 0种的感染诱导物质的初步检测正在进行中。

ObjectivePathogenic action of microbes on plants are often highly host-specific. Not in many instances the mode of this specific action had been given chemical and biological basis, but some of the cases have been attributed to the production of host determinants (infection-inducing substances) such as host-specific toxic products (HST) by the microbes. In the presently proposed work the subjects of study are a) isolation and structure determination of ACTG-toxin and HV-toxin related components produced by the fungi A. citri and H. victoriae, which cause epidemic brown spot disease of Dancy tangerine and Victoria blight disease of oat, respectively, b) disease of Dancy tangerine or study of structure-bioactivity relationship of HMT- and PM-toxins produced by the fungi H. maydis, race T and Phyllosticta maydis, respectively, which cause epidemic blight-disease on the same species of corn , c) preliminary examinations of the culture conditions and bioassay methods in order to isolate new infection-inducing substances from fungi, except known HST producing fungi, such as P. oryzae and H. maydis, race O.Resultsa) Two minor ACTG-toxin related compounds (ACTG-toxin G and H) and a new sesquiterpenoid, dihydrosporogen AO-1, have been isolated and their structures have been determined. Structure of HV-toxin M was determined as a new victorin C related compound and HV-toxin H was identified with victorin C. Isolation of the other minor components of HV-toxin are in progress.b) Thirty nine of HMT- and PM-toxin mimics have been systematically synthesized. Comparison of their biological activities suggested that bioactive conformations of HMT- and PM-toxins are certain cyclic forms.c) Preliminary examination& of infection-inducing substances from P. oryzae and H. maydis, race 0 are in progress.