【作者】 周佳；

【导师】 阮汉利；

【作者基本信息】 华中科技大学 ， 药物化学， 2020， 硕士

【摘要】 微生物次生代谢产物研究是天然产物研究的重要方向。为了获得结构新颖、具有良好生物活性的天然产物,本课题组以土赤壳属真菌Ilyonectria sp.sb65为研究对象,进行了次级代谢产物的结构及其活性研究。本文运用各种现代色谱分离技术（硅胶柱层析、ODS柱层析、凝胶柱层析、HPLC等）对该菌株的大米固体发酵物进行了分离纯化,一共分得64个化合物。随后,运用各种波谱学技术（NMR,MS,IR,UV,X-ray crystallographic,CD）确定了其结构,包含有3个16元间二羟基苯甲酸大环内酯类(RAL₁₆),49个14元间二羟基苯甲酸大环内酯类(RAL₁₄),1个12元间二羟基苯甲酸大环内酯类(RAL₁₂),2个其它类间二羟基苯甲酸内酯类化合物以及9个他汀类化合物（1-46,59a为新化合物）。其中,化合物1-3为首次发现的天然来源的RAL₁₆类化合物。另外,我们对分离得到的部分单体化合物进行了细胞毒活性、TRAIL增敏活性及免疫抑制活性筛选。首先,对化合物1-13,17-20,22-24,27,30-34,36,41进行了细胞毒活性筛选,筛选所用细胞株为人非小细胞肺癌细胞A549,人肾细胞腺癌细胞769-P和人结肠癌细胞HCT116。结果显示:绝大部分化合物对这三种癌细胞株均未表现出细胞毒作用,只有化合物4具有中等强度的细胞毒作用,当其浓度为50μM时,A549,769-P,HCT116细胞的存活率分别为29.8%,32.6%,34.9%。随后对化合物1-11,13,17-20,22,24,27,30-34,36,41进行了TRAIL增敏活性筛选,评估了这些化合物与TRAIL联用时对A549细胞存活率的影响。结果显示:36（50μM）与TRAIL（100 ng/ml）联用后的细胞存活率相对于单用TRAIL（100 ng/ml）降低了37.5%,而阳性对照组的细胞存活率降低了29.3%,由此可以看出,36是有潜力的增敏TRAIL活性的小分子化合物,值得进一步的研究。最后,对化合物1-13,17-20,22-24,27,30-34,36,41进行了免疫抑制活性筛选。结果显示3、4、13、36对T、B细胞的增殖都显示出显著的抑制作用,6、7、10对B细胞的增殖显示出选择性抑制作用,其中6表现出显著的抑制作用,12对T细胞的增殖显示出选择性中等强度抑制作用。更多还原

【Abstract】 Research on microbial secondary metabolites is an important direction for natural product researches.In order to obtain natural products with novel structure and great biological activity,our research group studied the structure and activity of secondary metabolites of one fungus Ilyonectria sp.sb65,which was isolated from the soil near the fibrous roots of Schisandra bicolor var.tuberculata growed in Xinning County of Hunan Province.In this paper,various modern chromatographic separation techniques were used to isolate and purify the fermentation broth of the fungus on rice medium,and 64 compounds were obtained in total.Subsequently,the structures of these compounds were determined using various spectroscopy techniques（NMR,MS,IR,UV,X-ray crystallographic,CD）.The isolated compounds included three 16-membered resorcylic acid lactones(RAL₁₆),forty-nine 14-membered resorcylic acid lactones(RAL₁₄),one 12-membered resorcylic acid lactone(RAL₁₂),two other types of resorcylic acid lactones and nine statins（1-46,59a are new compounds）.Among them,compounds 1-3 represent the first class of naturally produced RAL₁₆,with only a few synthesized ones being reported before.In addition,we estimated some isolated compounds for their cytotoxic activity,sensitization activity of TRAIL,and immunosuppressive activity.Firstly,compounds 1-13,17-20,22-24,27,30-34,36,41 were tested for their cytotoxic activities against A549 human lung adenocarcinoma,769-P human renal cell carcinoma,and HCT116 human colorectal cancer cell lines.The results dispalyed that most of the compounds did not show cytotoxicity against these three cancer cell lines,only compound 4 had moderate cytotoxicity.When the concentration of 4 was 50μM,the viability of A549,769-P,HCT116 cells were 29.8%,32.6%,and 34.9%,respectively.Subsequently,compounds 1-11,13,17-20,22,24,27,30-34,36,41 were screened for TRAIL sensitization activities to A549.The results showed that the cell viability of 36（50μM）combined with TRAIL（100 ng/ml）was reduced by 37.5%compared to TRAIL alone（100 ng/ml）,while the cell viability of the positive control group was reduced by 29.3%.It can be seen that 36 was a potential compound that can increase the sensitivity of TRAIL and deserves further study.Finally,compounds 1-13,17-20,22-24,27,30-34,36,41 were evaluated for their immunosuppressive activities.The results showed that 3,4,13,and 36 displayed strong inhibitory effects on T and B cell proliferation.Compounds 6,7,and 10 showed selective inhibitory effects on B cell proliferation,of which 6 showed strong inhibition effect.Compound 12 showed selective moderate-intensity inhibitory effect on T cell proliferation.更多还原