目的 研究绞股蓝总皂苷及其水解产物中达玛烷型四环三萜类化合物及其降糖活性。方法 采用反复硅胶柱色谱法、重结晶法和半制备液相色谱法等，对绞股蓝总皂苷水解产物和总皂苷进行系统分离，结合NMR数据鉴定了化合物的结构。利用体外抑制α-葡萄糖苷酶和蛋白酪氨酸磷酸酶1B（PTP1B）活性模型进行化合物活性筛选，并对活性较强的化合物进行了酶抑制动力学研究，采用计算机辅助药物设计的活性位点分析法，对PTP1B与化合物的相互作用进行对接模拟。结果 从绞股蓝总皂苷酸水解产物中分离得到7个化合物，分别鉴定为gpsapogenin A（1）、20（S）-人参二醇（2）、gypensapogenin F（3）、20（R）-原人参二醇（4）、（23S）-3β-羟基达玛-20，24-二烯-21-羧酸21，23-内酯（5）、gypsapogenin A（6）和（20S，24S）-3β，20，21β，23β，25-五羟基-21，24-环氧达玛烷（7）；从总皂苷中分离得到5个化合物，分别鉴定为（20R，23R）-3β，20-二羟基达玛-24-烯-21-羧酸21，23-内酯-3-O-[α-L-吡喃鼠李糖基（1→2）][β-D-吡喃木糖基（1→3）]-6-O-乙基-β-D-吡喃葡萄糖苷（8）、（20S，23S）-3β，20-二羟基达玛-24-烯-21-羧酸21，23-内酯-3-O-[α-L-吡喃鼠李糖基（1→2）][β-D-吡喃木糖基（1→3）]-6-O-乙基-β-D-吡喃葡萄糖苷（9）、（20R，23R）-19-醛基-3β，20-二羟基达玛-24-烯-21-羧酸21，23-内酯-3-O-[α-L-吡喃鼠李糖基（1→2）][β-D-吡喃木糖基（1→3）]-α-L-吡喃阿拉伯糖苷（10）、（20S）-3β，20，21-三羟基达玛-23，25-二烯3-O-{[α-L-吡喃鼠李糖基（1→2）][β-D-吡喃木糖基（1→3）]-β-D-吡喃葡萄糖基}-21-O-β-D-吡喃葡萄糖苷（11）、（20S，23S）-3β，20-二羟基达玛-24-烯-21-羧酸21，23-内酯3-O-[α-L-吡喃鼠李糖基（1→2）][β-D-吡喃木糖基（1→3）]-β-D-吡喃葡萄糖苷（12）。结论 除化合物4，其他化合物对α-葡萄糖苷酶和PTP1B均具有抑制活性。化合物9的活性最好，其半数抑制浓度（IC₅₀）值分别为2.10和1.07 μmol/L。

Objective To determine the total saponins from Gynostemma pentaphyllum, the dammarane-type triterpenoids of its hydrolysate, and its hypoglycemic activity. Methods Compounds from the acid hydrolyzate extracts and total saponins were isolated by silica gel, recrystal and preparative liquid chromatography, and their structures were identified by the NMR spectral analysis. The sensitive screening modles of α-glucosidase and PTP1B inhibitors were established in vitro. The inhibitory kinetics of compounds were also investigated. Using the method of computer aided drug design of active site, PTP1B interact with the strongest active compound for docking simulation. Results Seven compounds were isolated from the acid hydrolyzate of total saponins, which identified as gpsapogenin A (1), 20(S)-panaxadiol (2), gypensapogenin F (3), 20(R)-protopanaxadiol (4), (23S)-3β-hydroxydama-20,24-diene-21-carboxylic acid 21,23-lactone (5), gypsapogenin A (6), and (20S,24S)-3β,20,21β,23β,25-pentahydroxy-21,24-epoxydammarane (7). Five compounds were isolated from total saponins, including (20R,23R)-3β,20-dihydroxydammar-24-en-21-oic acid 21,23-lactone 3-O-[α-L-rhamnopyranosyl(1→2)] [β-D-xylopyranosyl(1→3)]-6-O-acetyl-β-D-glucopyranoside (8), (20S,23S)-3β,20-dihydroxydammar-24-en-21-oic acid 21,23-lactone 3-O-[α-L-rhamnopyranosyl(1→2)] [β-D-xylopyranosyl(1→3)]-6-O-acetyl-β-D-glucopyranoside (9), (20R,23R)-19-oxo-3β,20-dihydroxydammar-24-en-21-oci acid 21,23-lactone3-O-[α-L-rhamnopyranosyl-(1→2)] [β-D-xylopyranosyl(1→3)]-α-L-arabinopyranoside (10), (20S)-3β,20,21-trihydroxydammar-23,25-diene 3-O-{[α-L-rhamnopyranosyl(1→2)] [β-D-xylopyranosyl(1→3)]-β-D-glucopyranosyl}-21-O-β-D-glucopyranoside (11), and (20S,23S)-3β,20-dihydroxydammar-24-en-21-oic acid and 21,23-lactone 3-O-[α-L-rhamnopyranosyl(1→2)] [β-D-xylopyranosyl-(1→3)]-β-D-glucopyranoside (12). Conclusion Beside compound 4, the other compounds showed inhibitory activity against α-glucosidase and PTP1B. For the α-glucosidase and PTP1B inhibitions assay, compound 9 indicated the strongest inhibitory effect with IC₅₀ 2.10 and 1.07 μmol/L, respectively.

R284.1

国家自然科学基金青年科学基金项目（81602983）