Some Geranium species have been used to treat diabetes. To evaluate the scientific basis of this ethnopharmacological use, we aimed to isolate potent α-glucosidase inhibitory metabolites of Geranium asphodeloides Burm. through in vitro bioactivity-guided fractionation. All the tested extracts showed high α-glucosidase inhibitory effect compared to acarbose. Among the tested extracts, the ethyl acetate subextract showed the highest activity with an IC₅₀ value of 0.85 ± 0.01 µM. A hydrolysable tannin, 1,2,4-tri-O-galloyl-β-d-glucopyranose (1), and five flavonoid glycosides, kaempferol-3-O-α-rhamnopyranoside (2), kaempferol-3-O-α-arabinofuranoside (3), quercetin-3-O-β-glucopyranoside (4), quercetin-3-O-α-rhamnopyranoside (5), and quercetin-3-O-α-rhamnofuranoside (6), were isolated from the ethyl acetate subextract. Their structures were identified by 1D- and 2D-NMR experiments. 1 exhibited the highest α-glucosidase inhibitory effect, approximately 61 times more potent than positive control, acarbose, with an IC₅₀ value of 0.95 ± 0.07 µM. Also, 2 was more potent than acarbose. An enzyme kinetics analysis revealed that compounds 2, 3 and 4 were competitive, whereas 1 and 6 uncompetitive inhibitors. Molecular docking studies were performed to get insights into inhibition mechanisms of the isolated compounds in the light of the enzyme kinetic studies using various binding sites of the enzyme model.

一些天竺葵已被用于治疗糖尿病。为了评估这种民族药理学用途的科学基础，我们旨在分离天竺葵二倍体伯姆的有效α-葡萄糖苷酶抑制代谢物。通过体外生物活性指导的分级分离。与阿卡波糖相比，所有测试的提取物均显示出高的α-葡萄糖苷酶抑制作用。在测试的提取物中，乙酸乙酯亚提取物表现出最高的活性，IC ₅₀值为0.85±0.01 µM。可水解单宁1,2,4-三-O - galloyl - β - d-吡喃葡萄糖（1）和5种类黄酮苷，kaempferol-3- O - α-鼠李吡喃糖苷（2），kaempferol-3- O - α - arabinofuranoside （3），槲皮素3- O - β-葡萄糖吡喃糖苷（4），槲皮素3-从乙酸乙酯亚提取物中分离出O - α-鼠李糖吡喃糖苷（5）和槲皮素-3 - O - α-鼠李糖呋喃糖苷（6）。通过1D和2D-NMR实验鉴定了它们的结构。1个表现出最高的α-葡萄糖苷酶抑制作用，效力是阳性对照阿卡波糖约61倍，IC ₅₀值为0.95±0.07 µM。另外，2比阿卡波糖更有效。的酶动力学分析表明，化合物2，3和4分别为竞争性的，而1种6缺乏竞争力抑制剂。使用酶模型的各种结合位点，根据酶动力学研究，进行了分子对接研究以深入了解分离的化合物的抑制机理。