茶藤生物碱成分的分离鉴定及抗肿瘤活性研究

Isolation and identification of alkaloids from Melodinus magnificus and their antitumor activity

目的对茶藤Melodinus magnificus的生物碱成分进行分离、鉴定和抗肿瘤活性研究。方法采用薄层色谱、柱色谱等色谱方法对总生物碱浸膏进行分离和纯化。通过ESI-MS、1H-NMR、13C-NMR等波谱技术和文献对比等方法鉴定生物碱化合物的结构,并采用MTT法对分离得到的生物碱化合物进行抗肿瘤细胞(人肝癌HepG2细胞、乳腺癌MCF7细胞和人肺癌A549细胞)活性筛选,随后利用网络药理学和分子对接技术对具有抗肿瘤活性生物碱化合物的潜在靶点和作用通路进行预测。结果从茶藤枝叶总生物碱中共获得10个化合物,分别鉴定为strictamine(1)、deacetylakuammiline(2)、19-(Z)-akuammidine(3)、14,15-didehydrovincamine(4)、14,15-didehydro-16-epi-vincamine(5)、19-(S)-methoxytubotaiwine(6)、19-(R)-methoxytubotaiwine(7)、rhazimine(8)、rhazicine N4-oxide(9)和rhazicine(10)。抗肿瘤活性实验发现7个生物碱化合物(1、4~9)对3种肿瘤细胞株具有较显著的增殖抑制活性,半数抑制浓度(median inhibition concentration,IC_(50))值在0.40~1.16μmol/L。分子对接结果显示7个生物碱化合物能够与蛋白稳定结合,结合能范围-31.35~46.75 kJ/mol,且通过4个关键靶标基因RXRA、SRC、MAPK1、PIK3R1起到抗多种肿瘤的作用。结论所有化合物均为首次从该植物中分离得到。通过整合分离、鉴定、抗肿瘤活性筛选和网络药理学方法初步阐述了茶藤的抗肿瘤活性物质基础和作用机制,为寻找抗肿瘤药物提供了新的资源。

Objective To isolate and identify the antitumor activity of alkaloids from Melodinus magnaficus.Methods The separation and purification of the total alkaloid extract were carried out by preparative thin layer chromatography and column chromatography.The structures of the isolated alkaloids were identified by ESI-MS,~1H-NMR,13C-NMR,and by comparing with literature.MTT method was used to evaluate the antitumor activity of all monoterpene indole alkaloids.Network pharmacology and molecular docking technologies were used to predict the potential targets of alkaloids with cytotoxity.Results A total of 10 alkaloid compounds were obtained from the extract of total alkaloids from branches and leaves of M.magnificus.They were identified as strictamine(1),deacetylakuammiline(2),19-(Z)-akuammidine(3),14,15-didehydrovincamine(4),14,15-didehydro-16-epivincamine(5),19-(S)-methoxytubotaiwine(6),19-(R)-methoxytubotaiwine(7),rhazimine(8),rhazicine N~4-oxide(9),and rhazicine(10),respectively.All alkaloids were isolated from this plant for the first time.The results of MTT screening showed that seven alkaloid compounds(1,4—9)had significant inhibitory activity on the proliferation of three tumor cell lines,with IC_(50) values ranging from 0.40 to 1.16μmol/L.Molecular docking results showed that they could stably bind to proteins with binding energy ranging from-31.35 to 46.75 kJ/mol.They possibly play antitumor roles through four key target genes RXRA,SRC,MAPK1,and PIK3R1.Conclusion In this study,through integrating isolation,identification,anti-tumor activity screening,and network pharmacology methods,the substance basis and mechanism of antitumor activity of M.magnaficus are preliminarily expounded,which provide new resources for finding antitumor drugs.