极地海洋微生物抗肿瘤活性次级代谢产物研究

Due to the unique hard living environment, the secondary metabolites of polar marine microorganisms represent a structurally diverse family of natural products with various biological activities and pharmacological properties, which are the important source of marine drugs. The project focused on the characteristic secondary metabolites of three polar marine microorganisms. The selected strains were applied the anti-tumor activity screening model in vitro, combined with characteristic TLC spot colour and HPLC-DAD-MS chromatography/spectroscopy hyphenated techniques to isolate the pimarane diterpenes, chlorinated phenolic sesquiterpenes, and epipolythiodioxopiperazines from three strains, respectively. The absolute structure of new compounds were determined by extensive spectroscopic analyses and calculated ECD spectra. Moreover, the fermentation conditions of the bioactive strains were optimized to accumulate the quantity and quality of the targeted active compounds for the anti-tumor evaluation. The anti-tumor activity of the isolated compounds were evaluated to discuss their structure-activity relationship. The anti-tumor biological mechanism of the potent biological metabolites will also be studied. The project intended to discover the new leads with significant potent anti-tumor activity, which can provide an important basis for the rational and efficient use of polar marine microorganisms resources.

极地海洋微生物因其特殊极端的生境，使其次生代谢产物具有多样的结构和显著的活性，是海洋创新药物的重要来源。本项目针对三株含有特征次生代谢产物的极地微生物菌株，利用体外抗肿瘤活性筛选模型指导追踪分离，结合TLC特征显色与HPLC-DAD-MS等色谱/光谱联用技术，定向追踪分离该三种菌株发酵物中的海松烷型二萜、氯代酚醛倍半萜烯和多硫代二酮哌嗪类化合物。运用现代光谱学技术结合计算化学的方法，确定单体化合物的平面及绝对构型。并对活性菌株的发酵条件进行优化，以累积目标活性化合物。评价化合物的抗肿瘤活性，探讨其构效关系，研究强活性化合物的抗肿瘤作用机制，旨在发现活性显著、作用机制明确的新型抗肿瘤先导化合物，为我国极地微生物药用资源的发掘和合理利用提供重要依据。

基于课题组前期工作基础，对实验室菌种库中的极地海洋微生物进行抗肿瘤活性筛选，选定5株菌株Eutypella sp. D-1、Penicillium sp. S-1-18、Nectria sp. B-13、Aspergillus sp. S-3-62和Geomyces sp. 3-1进行发酵条件优化、规模发酵和后续活性成分研究。结合化合物HPLC-DAD-MS/NMR信息、分子网络信息以及多维化学策略，结合抗肿瘤活性追踪，快速定位目标活性新分子。综合运用现代波谱学手段，结合圆二色谱法（CD）、改良的Mosher法、量子化学计算ECD等立体构型确定方法，确定化合物的结构。共分离鉴定85个化合物，其中新化合物25个，新骨架化合物2个，其中新骨架化合物eutypellenone A和eutypellenone B的发现被（Nat. Prod. Rep., 2018, 35,1024）评为“热点报道”。在全面评价多个系列化合物的体外抗肿瘤活性的基础上，更深层次探讨构效关系，获得4个含“环丙基”官能团且具有强烈抗肿瘤活性的海松烷二萜类化合物，2个具有强抗肿瘤活性的氯代酚醛倍半萜烯类化合物。并通过Hoechst染色和细胞凋亡实验，检测强活性分子libertellenone H对多种胰腺癌细胞的生长抑制情况。通过该项目的实施，为后续抗肿瘤极地海洋药物的研发提供先导分子和模板分子，对我国开发利用极地海洋药用微生物资源具有重要的指导意义。.在该项目的资助下，共发表论文11篇，其中SCI论文9篇，申请国家发明专利2项，培养硕士研究生4名，博士研究生1名。