半枝莲抗肝癌活性部位的化学成分研究

Chemical constituents of the anti-liver cancer active site of Scutellaria barbata

前期研究发现,半枝莲(Scutellaria barbata)全草醇提物的乙酸乙酯萃取部位经大孔吸附树脂处理,其70%乙醇洗脱部位具有较好的抗肝癌活性。为明确其活性成分,该研究采用硅胶柱色谱、Sephadex LH-20柱色谱、制备TLC、半制备液相色谱等对活性部位进行分离和纯化,运用多种波谱分析方法鉴定了单体化合物结构,并利用CCK-8法评价了所有单体化合物对人肝癌HepG2细胞体外增殖抑制活性,同时利用分子对接技术考察了活性最好的化合物与肝癌靶标的结合情况。结果表明:(1)从该活性部位共分离得到14个化合物,包括12个新克罗烷型二萜类化合物和2个黄酮类化合物,分别鉴定为scutefolide C(1)、6-乙酰氧基-7-烟酸酰氧基半枝莲碱G(2)、scutestrigillosin D(3)、scutehenanine D(4)、半枝莲碱A(5)、半枝莲碱B(6)、7-烟酸酰氧基半枝莲碱H(7)、半枝莲碱N(8)、半枝莲碱Y(9)、barbatin A(10)、barbatin B(11)、barbatin D(12)、5,7,6′-三羟基-2′-甲氧基黄酮醇(13)和5,8-二羟基-6,7-二甲氧基黄酮(14)。其中,化合物1-3、13、14为首次从该植物中分离得到。(2)活性测试结果显示,化合物4、7、10-12表现出较弱的HepG2细胞增殖抑制活性,化合物6的细胞增殖抑制活性和阳性对照(顺铂)活性接近,而化合物5表现出比顺铂更强的细胞增殖抑制活性。(3)分子对接结果显示,化合物5和化合物6与肝癌靶蛋白VEGF-2均具有良好的结合力。该研究结果不仅丰富了半枝莲的化学物质类群,也为进一步深入研究活性化合物抗肝癌的作用机制提供了参考。

In previous study,the ethanol extract of Scutellaria barbata was partitioned with petroleum ether and EtOAc,respectively.The ethyl acetate extract site was subjected to column chromatography over macroporous adsorption resin eluting with gradient ethanol.The 70%ethanol elution fraction exhibited good anti-liver cancer activity.To clarify the active ingredients,the active site was separated and purified by silica gel column chromatography,Sephadex LH-20 column chromatography,preparative TLC,and semi preparative liquid chromatography,etc.Multiple spectroscopic analysis methods were used to identify the structure of the monomer compounds,and CCK-8 method was used to evaluate the inhibitory activity of all compounds on the proliferation of human liver cancer HepG2 cells in vitro.At the same time,molecular docking technology was used to investigate the binding of the most active compounds with target proteins VEGF-2 and FGFR-1,which were obtained from targeted drug for liver cancer.The results were as follows:(1)A total of 14 compounds were isolated from the active site,including 12 neo-clerodane diterpenoids and 2 flavonoids,which were identified as scuefolide C(1),6-acetoxy-7-nicotinoyloxyscutebarbatine G(2),scutestrigillosin D(3),scutehenanine D(4),scutebarbatine A(5),scutebarbatine B(6),7-O-nicotinoyloxyscutebarbatine H(7),scutebarbatine N(8),scutebarbatine Y(9),barbatin A(10),barbatin B(11),barbatin D(12),5,7,6′-trihydroxy-2′-methoxyflavonol(13)and 5,8-dihydroxy-6,7-dimethoxyflavone(14).Compounds 1-3 and 13,14 were isolated from this plant for the first time.(2)The results of cell proliferation inhibition activity test showed that compounds 4,7,10-12 exhibited weaker cell proliferation inhibitory activity against HepG2,and Compound 6 exhibited similar cell proliferation inhibitory activity to the positive control(cisplatin),while Compound 5 exhibited stronger cell proliferation inhibitory activity than cisplatin.(3)The molecular docking results showed that Compound 5 and Compound 6 had good binding affinity with target protein VEGF-2,which binded to residues such as GLY-841,LEU-840,ASN-923,ARG-1032 in VEGF-2 protein through hydrogen bonding.At the same time,Compound 5 and Compound 6 exhibited poor binding affinity with target protein FGFR-1.The results of this study not only enrich the chemical groups of S.barbata,but also provide a reference for further study on the mechanism of active compounds against liver cancer.