[关键词]
[摘要]
目的 研究鳢肠Eclipta prostrata干燥地上部分(墨旱莲)的活性化学成分。方法 利用大孔树脂、硅胶和凝胶LH-20等柱色谱及半制备高效液相色谱方法进行分离纯化,综合分析质谱和核磁共振(1H-NMR、13C-NMR、DEPT、HSQC、1H-1H COSY、HMBC和ROESY)等波谱数据对化合物进行结构鉴定,采用体外酶活实验测试化合物的α-葡萄糖苷酶抑制活性。结果 从墨旱莲乙醇提取物的醋酸乙酯萃取部位中共分离得到8个化合物,分别鉴定为7β-羟基-豆甾醇-3-O-β-D-吡喃葡萄糖苷(1)、7α-羟基-豆甾醇-3-O-β-D-吡喃葡萄糖苷(2)、7α-羟基-谷甾醇-3-O-β-D-吡喃葡萄糖苷(3)、3β,23-二羟基-30-去甲齐墩果-12,20(29)-二烯-28-酸(4)、山茶酮二醇(5)、刺囊酸-3-O-(6-O-乙酰基)-β-D-吡喃葡萄糖苷(6)、墨旱莲皂苷I(7)和墨旱莲皂苷IV(8)。体外活性测试结果表明,化合物2具有α-葡萄糖苷酶抑制活性,半数抑制浓度(IC50)值为(11.7±4.2)μmol/L。结论 化合物1为1个新的豆甾醇类型葡萄糖苷,命名为墨旱莲皂苷XIV;化合物3~5为首次从该植物中分离得到;化合物2对α-葡萄糖苷酶有一定的抑制作用。
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[Abstract]
Objective To investigate the bioactive chemical constituents of the aerial parts of Eclipta prostrata. Methods The compounds were isolated and purified by macroporous absorption resin, silica gel, Sephadex LH-20 and semi-preparative HPLC chromatography. Their structures were determined by MS and NMR data. The α-glucosidase inhibitory activities of compounds 1 and 2 were tested by in vitro screening assay. Results A total of eight compounds were isolated from the ethyl acetate partition of the ethanol extract of E. prostrata. They were identified as 7β-hydroxystigmasterol 3-O-β-D-glucopyranoside (1), 7α-hydroxystigmasterol 3-O-β-D-glucopyranoside (2), 7α-hydroxysitosterol 3-O-β-D-glucopyranoside (3), 3β,23-dihydroxy-30-norolean-12,20 (29)-dien-28-oic acid (4), camellenodiol (5), echinocystic acid-3-O-(6-O-acetyl)-β-D-glucopyranoside (6), eclalbasaponin I (7) and eclalbasaponin IV (8). Compound 2 exhibited strong inhibition against α-glucosidase with an IC50 value of (11.7 ±4.2) μmol/L. Conclusion Compound 1 is a new compound named eclalbasaponin XIV and compounds 3-5 are reported from this herb for the first time. Steroidal glycosides could be the anti-hyperglycaemic components in E. prostrata by inhibiting α-glucosidase.
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[基金项目]
山东省中医药科技发展计划项目(2011-145)