内生真菌毛壳霉新颖次生代谢产物化学成分及抗肿瘤活性研究

Mutualism between endophytic fungi and host are closely related to the growth, resistance to diseases, pests and active ingredients accumulate regulation of the host. Endophytic fungi secondary metabolites have a wide range of biological activities due to their structural diversity and have been proved to be a major source of drug lead compounds. Ferment with the activators or inhibitors could induce fungi to form novel natural products. In previous work, a strain of Chaetomium sp fungi, with cytotoxic activity, was isolated from the endophytic fungi. A new compound (6) from the extract exhibited antitumor activity and could decrease the expression levels of HIF-1α and VEGF. In this study, enzyme inhibitors or activators intervention will be used to obtain more kinds of active compounds under characteristic NMR signals, HPLC-MS neutral losses and PRCE analysis. Secondary metablites of the extracts will systematically investigate under activity tracking for avoiding loss of ingredients. In addition, according to the results of activity evaluation, antineoplastic activity and mechanism of target compounds will be studied and lead compounds might be found.

内生真菌与宿主植物长期互利共生，与宿主生长、抗病虫害、病原体拮抗和有效活性成分积累等密切相关，其结构新颖的次生代谢产物为药用活性化合物重要来源并成为研究热点。人工添加次生代谢产物相关酶合成调控剂可促其沉默基因表达，得到普通培养不产生的新颖次生代谢产物。本组从具有显著抑制肿瘤细胞增殖作用的毛壳属内生真菌发酵提取物中分离得到了7个新的吲哚二酮哌嗪衍生物，化合物6在细胞水平可抑制HIF-1α和VEGF水平进而发挥抗肿瘤作用。培养基加入1,2-二甲基吲哚可增加此类化合物种类和含量。HPLC-MS/MS分析表明此菌种发酵提取物中次生代谢产物非常丰富。本项目通过目标产物NMR特征信号以及HPLC-MS特征中性丢失、子离子片段扫描监测，在不同发酵条件和代谢产物相关合成酶抑制剂干预下，得到富含新颖结构的发酵产物，再进行系统分离纯化，筛选得到抗肿瘤活性化合物并探讨作用机制，已期发现新颖的抗肿瘤先导化合物。

内生真菌与宿主植物长期互利共生，与宿主生长、抗病虫害、病原体拮抗和有效活性成分积累等密切相关，其结构新颖的次生代谢产物为药用活性化合物重要来源并成为研究热点。本项目实施过程中，采用一菌多产物策略，对菌种发酵产物进行系统分离，通过NMR，HR-MS， Marfey’s法，单晶衍射法等鉴定了25个化合物，包括8个新化合物，3个活性多硫代二酮哌嗪类化合物。化合物11和6抗肿瘤活性显著，化合物11通过细胞周期阻滞和细胞色素C/caspase-3途径诱导肿瘤细胞凋亡，化合物6可抑制3种结肠癌细胞系和3种肝癌细胞的细胞活力，且在低氧环境下其抑制作用更强，通过抑制PI3K/AKT/mTOR通路而降低了缺氧诱导因子1的表达和活性，可能是抑制肿瘤细胞的增殖其作用机制之一。本项目部分相关研究结果已发表论文8篇，其中SCI 论文6篇，获授权专利1项，为二酮哌嗪类抗肿瘤药物的开发提供了一定的研究基础。