落叶松针叶化学成分研究

Chemical constituents of Larix gmelinii needles

关键词:  落叶松针叶, 化学成分, 黄酮, 香草酸, 抑菌活性

Key words:  Larix gmelinii needles, chemical constituents, flavanone, vanillic acid, antibacterial activity

摘要:

该研究采用硅胶柱色谱、半制备型高效液相色谱和重结晶等方法对落叶松针叶乙酸乙酯萃取物进行分离纯化,利用NMR、MS现代波谱技术结合相关文献报道对分离得到的化合物进行结构鉴定,并对提取浸膏的抑菌活性进行了测试。结果表明:从落叶松针叶乙酸乙酯萃取物中分离得到15个化合物,分别鉴定为Larixol(1)、(2R)-5,4'-二羟基-6-甲基-7-甲氧基-黄酮(2)、2',4'-二羟基-4,6'-二甲氧基二氢查尔酮(3)、2',4-二羟基-4',6'-二甲氧基查尔酮(4)、2',4'-二羟基-4,6'-二甲氧基查尔酮(5)、异鼠李素(6)、4',5-二羟基-7-甲氧基-8-甲基黄酮(7)、山奈酚(8)、β-谷甾醇(9)、豆甾醇(10)、胡萝卜苷(11)、香草酸(12)、对羟基苯甲酸(13)、二甲基罗汉松脂素(14)、15-二十九烷醇(15)。其中,化合物2,4,5和7为首次从该属植物中分离得到。抑菌活性实验结果显示,乙酸乙酯萃取浸膏在浓度为5～100 mg·mL^-1时对大肠杆菌、枯草芽孢杆菌、蜡样芽孢杆菌和金黄色葡萄球菌的抑菌率分别为55%～70%、53%～72%、61%～71%和33%～65%。上述结果为更加深入探究落叶松针叶化学成分和药理活性提供了一定理论依据。

Abstract:

To study on chemical constituents and bioactivity of Larix gmelinii needles, separation and purification of ethyl acetate extract from Larix gmelinii needles were carried out by silica gel column chromatography, semi-preparative high performance liquid chromatography, and re-crystallization. The structures of isolated compounds were identified by analysis of spectra of MS, NMR, and compared with the reported conferences. The antibacterial activity of the extract was also tested. The results were as follows: Compounds 1-15 were isolated from the ethyl acetate extract and identified as Larixol(1),(2R)-5,4'-dihydroxy-6-methyl-7-methoxy flavone(2), 2',4'-dihydroxy-4,6'-dimethoxydihydro-chalcone(3), 2',4-dihydroxy-4',6'-dimethoxy-chalcone(4), 2',4'-dihydroxy-4,6'-dimethoxy-chalcone(5), isorhamnetin(6), 4',5-dihydroxy-7-methoxy-8-methyl flavone(7), kaempferol(8), β-sitosterol(9), stigmasterol(10), daucosterol(11), vanillic acid(12), hydroxyl-benzoic acid(13), dimethyl-matairesinol(14), and 15-nonacosanol(15). Compounds 2, 4, 5, and 7 were isolated from the genus Pinus for the first time. The result of antibacterial activity indicated that the inhibition rates of ethyl acetate extract to Escherichia coli, Bacillus subtilis, B. cereus, and Staphylococcus aureus were 55%-70%, 53%-72%, 61%-71%, 33%-65%, respectively, at the concentration range of 5-100 mg·mL^-1. The results of this study will provide a theoretical basis for further study on the chemical composition and pharmacological activity of Larix gmelinii.