真菌中二聚烯化吲哚生物碱生物的生物合成机制与其药用功能导向的生物合成途径理性改造

Prenylated indole alkaloid dimers, such as Stephacidin B and Waikialoid A, are leading compounds with anti-tumor and anti-fungi activity, respectively, which were only obtained from fungi. However, it remains problematic to economically synthesize this kind of compounds. The problem is generally considered to overcome by elucidation of its biosynthesis pathway. However, till now, only a few steps in the biosynthetic pathway of notoamides, a monomer of prenylated indole alkaloid, have been elucidated, most of them are still elusive. In our application, Aspergillus ochraceus, which could produce waikialoid A in high yield, is chosen as subject. To efficiently identify all the genes involved in the biosynthesis of the compound, transcriptomics and metabonomics will be used together , which help us to find all the genes in the cluster, and then, elucidate its biosynthesis pathway, including Diels-Alderase. Moreover, by modification of its NRPS, more analogues of the compound could be obtained and their bioactivity will be further tested. Our research is significant to discover and develop more promising new drugs.

二聚烯化吲哚生物碱 Stephacidin B 和 Waikialoid A 是真菌特有的具有显著抗肿瘤和抗真菌活性先导化合物。该类化合物化学合成工艺繁琐、收率低，生物合成研究是解决其药源的有效途径。文献仅报道了其相关单体 notoamides 的部分生物合成基因的功能，因为常规生物信息学分析不能完整解析其基因簇。本申请项目拟以Waikialoid A高产的赭曲霉菌KM007菌株为研究对象，克隆其基因簇，通过基因敲除、差异转录组学与差异代谢谱分析，以期确定参与Waikialoid A生物合成的相关基因，阐明关键蛋白如Diels-Alderase的催化机制；探索理性改造NRPS丰富KM007菌株的代谢产物多样性，并开展相关生物活性研究。本申请项目研究对发现和发展新型的、更具临床应用前景的药物具有重要的意义。

真菌特有的烯化吲哚生物碱普遍具有显著的生物活性，是重要的先导化合物源泉, 特别是具有显著抗肿瘤和抗真菌活性得二聚体Stephacidin B 和 Waikialoid ,但该类化合物结构复杂，化学合成工艺繁琐、收率低，无法满足开发的需求，研究其生物合成途径被认为是解决其药源的有效途径。然而，文献仅报道了其相关单体 notoamides 的部分生物合成基因的功能,关键的二氮辛烷以及苯并吡喃环结构单元的生物合成途径并不清楚。本项目采用过基因敲除、异源重建、体内外反应等方法，揭示了参与二聚烯化吲哚生物碱生物合成的所有基因，解析了大部分基因的功能，特别是结合化学计算，我们发现了第一个P450也是一个Diels-Alderase。本研究的发现对发现和发展新型的、更具临床应用前景的药物具有重要的意义。