蓝桉果实中抗髓母细胞瘤活性成分酰基间苯三酚衍生物的快速定向发现及结构修饰研究

Medulloblastoma (MB) is the most common malignant brain tumor in children. It is characterized with rapid growth, earlier intracranial dissemination and high recurrence incidence. MB patients usually have poor prognosis and suffers from direct surgical damages, long-term side effects and developmental defects. Therefore, new effective and less toxic therapeutic approaches including anti-cancer drugs, targeting specific to medulloblastoma are urgently required to be developed. Natural compounds are always an important source of antitumor candidate agents due to their diversity structures and functions. In our previous work, a medulloblastoma cell line, named MB39, has been established and characterized. In an ongoing project towards the discovery of new antitumor agents from plants, high-throughput cell-based screening for inhibited medulloblastoma cell from natural product library (Flash fractions) was developed in our group. Our earlier study showed that several plant fractions (including the fruits of Eucalyptus globulus Labill.) inhibited MB39 cells. Moreover, a few phloroglucinol-terpene adducts exhibited significant in vitro cytotoxicities against several cancer cell lines (MB39, Huh-7, BGC-823,etc). The phloroglucinol-terpene adducts are a class of interesting secondary metabolites typical to plants in the family Myrtaceae, especially Eucalyptus species. These preliminary findings attracted our great interest. In order to obtain anti-medulloblastoma bioactive compounds and more novel phloroglucinol-terpene adducts from the fruits of E. globulus, bioassay-guided separation and LC-MS segmentation strategy guided separation will be used in this project. The structures of the active compounds will thereafter be elucidated by spectroscopic methods. Moreover, we will structurally modify three known active compounds by chemical synthesis along with structure-activity relationship (SAR) analysis. Additionally, further investigations will be done on the action mechanism of anti-medulloblastoma substances.This study will give clues to new potential anti-cancer drugs for medulloblastoma.

髓母细胞瘤是一种具有高侵染力的儿童恶性脑肿瘤，死亡率居儿童恶性肿瘤之首，目前尚缺乏特异有效的治疗方法和抗癌药物。本课题组基于已建立的小鼠髓母细胞瘤细胞筛选模型和特色天然产物组分库，首次发现蓝桉果实醇提物中的三个酰基间苯三酚衍生物（包括两个新化合物）对多种肿瘤细胞（髓母细胞瘤MB39、肝癌Huh-7、胃癌BGC-823等）具有较好的抑制作用。为得到更多结构新颖、活性更强、毒副作用更小的抗髓母细胞瘤的活性化合物，本项目拟采用生物活性导向分离与LC-MS质谱裂解规律导向分离相结合的方法，从蓝桉果实醇提物中快速得到更多抑制髓母细胞瘤增殖的酰基间苯三酚衍生物，并对已得到的三个活性化合物进行结构修饰优化及构效关系研究，并进一步探讨其作用机制。本研究将为深入开发利用该植物资源及寻找新型的治疗髓母细胞瘤的创新药物提供新的线索和科学依据。

髓母细胞瘤是一种具有高侵染力的儿童恶性脑肿瘤，死亡率居儿童恶性肿瘤之首，目前尚缺乏特异有效的治疗方法和抗癌药物。本项目以蓝桉果实天然产物组分库、髓母细胞瘤细胞筛选模型为研究对象，采用天然产物化学、生物活性跟踪、液相色谱-质谱分析导向分离等技术方法开展了一系列研究工作。构建了蓝桉果实化学成分组分库，建立了MB39和Daoy两种髓母细胞瘤细胞筛选模型，从蓝桉果实醇提物中分离纯化出20多个单体化合物，运用现代波谱尤其是二维核磁共振谱和高分辨质谱等技术解析其化学结构，主要为酰基间苯三酚衍生物、三萜、甾体、单萜等化合物。对所得到的化学组分及单体化合物进行了抗肿瘤活性测试，从中得到抑制髓母细胞瘤增殖活性很好的化合物LA-71以及对多种肿瘤细胞（人肝癌细胞Huh-7、人胃癌细胞BGC-823, KE-97、人外周血白血病T细胞Jurkat）具有较好抑制作用的化合物1和3。同时开展了对活性化合物进行有效提取富集方法和条件的优化，并采用计算机辅助模拟筛选设计针对GD2靶标的活性分子。本项目的研究结果为深入开发利用该植物资源及寻找新型的治疗髓母细胞瘤的创新药物提供了线索和科学依据。