六种我国特有松科濒危植物萜类成分及其抗2型糖尿病活性研究

Plant-derived natural products (NPs) have continued to play a significant role in the drug discovery and development process. The opportunity for identifying new chemical entities (NCEs) for emerging diseases depends on a diversity of drug-producing species. The decline in plant species numbers will continue to exacerbate complication in the discovery of new naturally derived drugs. Recently, several statistical surveys unveiled that the rare and endangered plants could serve as better sources for drug discovery than other botanic sources. A pioneering phylogenetic study of the terrestrial plants showed that nature-derived drugs are mainly produced by specific drug-productive plant families, and endangered species often belongs to these drug producing families. Therefore, there is a tremendous need to prioritize protection and utilization of these endangered plants at risk and facing extinction. Pinaceae is among the major plant families that produced high numbers of approved drugs. Previous studies have revealed terpenoids (especially diterpenoids) as the main characteristic secondary metabolites in Pinaceae plants. In fact, a number of species in this family are endangered with a total of 39 species recorded in the first volume of the China Plant Red Data Book (CPRDB) published in 1992. These include Pinus massoniana Lamb. var. hainanensis Cheng et L. K. Fu, Pseudotsuga sinensis Dode, Pseudotsuga gaussenii Flous, Pseudotsuga forrestii Craib, Keteleeria fortunei (Murr.) Carr., and Keteleeria hainanensis Chun et Tsiang, which have never or seldom been chemically or pharmacologically investigated. We found that all the MeOH extracts from the above six plants endemic to China exhibited pharmaceutical effects with varying inhibitory ratios against the human protein tyrosine phosphatase 1B (PTP1B) enzyme, a key target for the treatment of type 2 diabetes mellitus (T2DM). And our preliminary chemical analyses show that the extracts are rich in terpenoids (diterpenoids in particular). In this project, we propose to carry out a more systematic investigation on these crude extracts from the selected plants, highly likely leading to the identification of a series of novel diterpenoids with different (incl. novel) scaffolds. Thereafter, the purified NPs will be evaluated for their anti-diabetic activities by assessing their inhibition of the PTP1B enzyme and the 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1), and activation of the glucagon-like peptide 1 receptor (GLP-1R) and the adenosine 5′-monophosphate-activated protein kinase (AMPK). The anti-diabetic mechanisms of the active compounds will be further deliberated. Chemical derivatives of the identified major bioactive compound(s) will be prepared for sturucture-activity relationship (SAR) studies. The results will be of great significance not only for the initiative protection and efficient usage of the endangered plants native to China, but also for the development of new, safe and effective anti-diabetic drug candidate(s) from the valuable endangered Pinaceae plants.

濒危植物中新天然产物的数量和成药性远高于一般植物的平均水平。松科是能产生药物的主要植物科属之一，其多个物种处于濒危或渐危状态。研究表明萜类（尤其二萜）成分是松科植物主要特征次生代谢产物。中国植物红皮书所收载的六种濒危松科植物（雅加松、黄杉、华东黄杉、澜沧黄杉、油杉和海南油杉）的化学成分还未得到研究抑或研究不够深入。预实验时发现它们的醇提物均富含萜类成分且均具有一定的PTP1B抑制活性。本项目拟对上述我国特有松科植物中的萜类成分（含微量成分）开展深入发掘，以期发现一批新结构；针对多个与2型糖尿病（T2DM）相关的新型靶点（如PTP1B、11β-HSD1、GLP-1R、AMPK）对单体化合物进行活性评估，继而开展相关作用机制及体内药效研究；对部分分离量较大的活性化合物开展衍生化和构效关系探讨。研究成果将积极促进我国濒危松科植物的科学保护和开发利用，并为从中发现新型抗T2DM药物先导化合物奠定基础。

陆生植物长久以来一直是创新药物分子的重要来源，其中濒危植物代谢所产生的新天然产物的数量和成药性远高于一般植物的平均水平。松科位列最能产生化药的主要植物科属之一；该科植物因富含结构类型和生物活性均多样的萜类成分而广受关注，但相当部分松科物种处于濒危状态，仅《中国植物红皮书-稀有濒危植物（一）》里就收录了39种松科植物，其数量占该红皮书所收载植物总数的十分之一多。因此，对松科稀有濒危植物萜类成分开展系统性研究具有重要意义。.在本项目的资助下，我们选取了红皮书中化学成分尚未研究或未得到深入研究的六种松科植物——雅加松、黄杉、华东黄杉、澜沧黄杉、油杉和海南油杉的针叶/小枝（均可再生），对它们的萜类成分（含微量成分）开展深入系统研究，发现一批新结构。同时，在活性初筛结果指导下，利用多个与2型糖尿病（T2DM）相关的新型靶点（PTP1B，Drak 2，AMPK，GLP-1R，ACL和ACC1等）筛选模型对单体化合物生物活性进行评价，继而开展相关作用机制的探讨。采用现代分离纯化技术和结构解析方法，从所选松科植物中累计共分离并鉴定到目标萜类化合物220个，其中新化合物（含新骨架）80个。部分化合物表现出较强的体外抗T2DM的生物活性，并有一定的构效关系。.本项目资助发表SCI论文21篇（第一、第二和第三标注分别为9、11和1篇）、第一标注中文核心期刊论文3篇，另3篇已投或待投；参编学术专著3部；申请发明专利4项。项目执行期间共培养研究生10人，其中2人获硕士学位，4人获博士学位。项目组成员赴国外开展学术交流活动2次、国际国内学术会议邀请报告8次。项目实现了预期的研究目标。本研究成果不仅较大程度地丰富了天然萜类成分的研究内容和结构类型，亦为促进我国特有松科珍稀濒危植物的积极与科学保护以及开发利用提供了科学依据；更为重要的是为基于萜类结构的多靶点抗T2DM新型药物研发提供了新的线索和科学依据。