In this paper, the inhibition of α-amylase and α-glucosidase by nine pentacyclic triterpenes was determined. For α-amylase inhibitory activity, the IC₅₀ values of ursolic acid, corosolic acid, and oleanolic acid were 22.6 ± 2.4 μM, 31.2 ± 3.4 μM, and 94.1 ± 6.7 μM, respectively. For α-glucosidase inhibition, the IC₅₀ values of ursolic acid, corosolic acid, betulinic acid, and oleanolic acid were 12.1 ± 1.0 μM, 17.2 ± 0.9 μM, 14.9 ± 1.9 μM, and 35.6 ± 2.6 μM, respectively. The combination of corosolic acid and oleanolic acid with acarbose showed synergistic inhibition against α-amylase. The combination of the tested triterpenes with acarbose mainly exhibited additive inhibition against α-glucosidase. Kinetic studies revealed that corosolic acid and oleanolic acid showed non-competitive inhibition and acarbose showed mixed-type inhibition against α-amylase. The results provide valuable implications for the triterpenes (ursolic acid, corosolic acid, and oleanolic acid) alone or in combination with acarbose as a therapeutic agent for the treatment of diabetes mellitus.

本文确定了九种五环三萜对α-淀粉酶和α-葡萄糖苷酶的抑制作用。对于α-淀粉酶抑制活性，熊果酸，熊果酸和齐墩果酸的IC ₅₀值分别为22.6±2.4μM，31.2±3.4μM和94.1±6.7μM。对于α-葡萄糖苷酶抑制，IC ₅₀熊果酸，熊果酸，桦木酸和齐墩果酸的值分别为12.1±1.0μM，17.2±0.9μM，14.9±1.9μM和35.6±2.6μM。椰油酸和齐墩果酸与阿卡波糖的组合显示出对α-淀粉酶的协同抑制作用。被测三萜与阿卡波糖的组合主要表现出对α-葡萄糖苷酶的累加抑制作用。动力学研究表明，椰油酸和齐墩果酸显示出非竞争性抑制作用，阿卡波糖显示出对α-淀粉酶的混合型抑制作用。结果为单独或与阿卡波糖组合作为治疗糖尿病的三萜类（熊果酸，熊果酸和齐墩果酸）提供了有价值的启示。