雪层杜鹃中的黄酮类化合物及其抗氧化和抗炎活性研究

Flavonoids from Rhododendron nivale and their antioxidant and anti-inflammatory activities

本文研究雪层杜鹃提取物中的黄酮类化学成分及其抗氧化和抗炎活性。本研究采用硅胶柱色谱、Sephadex LH-20柱色谱和半制备高效液相色谱(HPLC)等多种色谱分离技术对雪层杜鹃的乙酸乙酯提取物进行分离纯化,并通过NMR、IR和HR-ESI-MS等方法共鉴定出8个黄酮类化合物,包括1个新化合物:3′,8-二甲氧基槲皮素-3-O-α-L-阿拉伯呋喃糖苷(1)和7个已知化合物:桑黄素-3-O-β-L-赖氧苷(2)、花旗松素-3-O-α-L-阿拉伯糖苷(3)、表儿茶素(4)、(–)-表没食子儿茶素(5)、(–)-儿茶素(6)、二氢杨梅素(7)、二氢槲皮素(8)。它们的抗氧化和抗炎活性利用H_(2)O_(2)氧化损伤模型和脂多糖诱导的一氧化氮生成模型分别测定。化合物2、4和8使H_(2)O_(2)损伤的SH-SY5Y细胞存活率从(44.0±2.3)%分别提高到了(80.6±0.4)%、(78.4±1.6)%和(81.9±1.7)%。化合物8也表现出一定的抗炎活性,IC_(50)值为37.7μmol/L。结果证明雪层杜鹃中的黄酮类化合物具有被发掘成抗氧化和抗炎先导化合物的潜力。

This study investigates the flavonoid compounds in the extracts of R.nivale and their antioxidant and anti-inflammatory activities.Various chromatographic separation techniques such as silica gel column chromatography,Sephadex LH-20 column chromatography,and semi-preparative high-performance liquid chromatography(HPLC)were used to separate and purify the ethyl acetate extracts of R.nivale.Using NMR,IR,and HR-ESI-MS,eight flavonoid compounds were identified,including a new one,3′,8-dimethoxyquercetin-3-O-α-L-arabinofuranoside(1),and seven known compounds:morin-3-O-β-L-lyxoside(2),(2 R,3 R)-taxifolin-3-O-arabinoside(3),epicatechin(4),(-)-epigallocatechin(5),(-)-catechin(6),dihydromyricetin(7),dihydroquercetin(8).Their antioxidant and anti-inflammatory activities were measured using a H_(2)O_(2)-induced oxidative damage model and a lipopolysaccharide-induced nitric oxide production model,respectively.Compounds 2,4 and 8 increased the viability of H_(2)O_(2)-damaged SH-SY5Y cells from(44.0±2.3)%to(80.6±0.4)%,(78.4±1.6)%and(81.9±1.7)%,respectively.Compound 8 also exhibited anti-inflammatory activity with an IC_(50)value of 37.7μmol/L.These results demonstrate that the flavonoid compounds in R.nivale have potential as lead compounds for developing antioxidant and anti-inflammatory agents.