山豆根地上部分的酪氨酸酶抑制活性成分筛选研究

Chemical constituents from the aerial parts of Sophora tonkinensis and their tyrosinase inhibitory activities

关键词:  壮药, 山豆根, 地上部分, 化学成分, 酪氨酸酶

Key words:  Zhuang medicine, Sophora tonkinensis, aerial part, chemical constituents, tyrosinase

摘要:

壮药山豆根,为豆科植物越南槐(Sophora tonkinensis)的干燥根和根茎,是非常重要的广西道地药材。为了更加合理地开发利用山豆根的地上部分,阐明其化学物质基础,该研究采用多种现代色谱分离方法对山豆根地上部分进行了系统分离,并通过现代波谱学方法对分离得到的单体化合物进行了结构鉴定,同时测试了单体化合物对酪氨酸酶的抑制活性。结果表明:(1)从山豆根地上部分分离得到10个化合物,分别为水杨酸(1)、对羟基苯甲酸(2)、木犀草素(3)、8-异戊烯基山萘酚(4)、槲皮素(5)、大豆素(6)、芒柄花素-7-O-β-D-葡萄糖苷(7)、刺芒柄花素(8)、鸢尾黄素(9)、金雀异黄素(10),所有化合物均首次从山豆根的地上部分中分离得到;(2)酪氨酸酶抑制活性的试验测试结果表明化合物4、7和9对酪氨酸酶均具有较强的抑制作用,其中化合物4的酪氨酸酶抑制活性最强,IC₅₀值为(1.58 ± 0.31)× 10^-5 mol·L^-1。该研究丰富了山豆根地上部分的化学物质基础及其生物活性,为山豆根非药用部位的深入开发利用奠定了基础。

Abstract:

Zhuang medicine Shandougen, the dry radix and rhizome of the plant Sophora tonkinensis from the Leguminosae family, is one of the most important and famous traditional Chinese medicine in Guangxi Zhuang Autonomous Region and also distributed in Yunnan and Guizhou provinces. According to the “Chinese Pharmacopoeia 2020”, Shandougen is used for clearing heat, removing toxicity, relieving sore throat and detumescence. In order to develop and utilize the aerial parts of S. tonkinensis more reasonably and scientifically, the studies for chemical constituents and their tyrosinase inhibitory activities of the aerial parts of S. tonkinensis were performed. Some modern chromatographic methods for the separation of chemical constituents were carried out, such as high-performance liquid chromatography, Sephadex LH-20 column chromatography, MCI gel CHP 20P column chromatography, silica gel column chromatography, and thin layer chromatography. The structures of the pure compounds were established on the basis of their spectroscopic data, including the spectra of HR-ESI-MS, ¹H NMR and ¹³C NMR. In addition, the isolated compounds were evaluated for their tyrosinase inhibitory activities through modern pharmacological methods. The results were as follows:(1)Ten compounds were separated from the aerial parts of S. tonkinensis and their structures were identified as salicylic acid(1), 4-hydroxybenzoic acid(2), luteolin(3), 8-prenylkeamferol(4), quercetin(5), daidzein(6), formononetin-7-O-β-D-glucoside(7), formononetin(8), tectorigenin(9), and genistein(10). All these compounds were isolated from the aerial parts of S. tonkinensis for the first time;(2)Compounds 4, 7 and 9 showed strong inhibitory effects toward tyrosinase after the evaluation for their biological activity. Particularly, Compound 4 showed the strongest inhibitory activity with the IC₅₀ value of(1.58 ± 0.31)× 10^-5 mol·L^-1. Compounds 4, 7 and 9 could be a potential tyrosinase inhibitor after the analysis of bioactivity results. The above results enrich the previous studies on the chemical constituents and biological activities of the aerial parts of S. tonkinensis, further providing the scientific basis for the development and utilization of the non-medicinal parts of this herb.