Mulberry leaves contain iminosugars, such as 1-deoxynojirimycin (1-DNJ), fagomine, and 2-O-α-D-galactopyranosyl deoxynojirimycin (GAL-DNJ) that inhibit α-glucosidase. In this study, we quantified iminosugars in Morus australis leaves and made the kinetic analysis in the hydrolysis of maltose by α-glucosidase. By LC-MS/MS, the concentrations of 1-DNJ, fagomine, and GAL-DNJ in the powdered leaves were 4.0, 0.46, and 2.5 mg/g, respectively, and those in the roasted ones were 1.0, 0.24, and 0.73 mg/g, respectively, suggesting that the roasting process degraded iminosugars. Steady-state kinetic analysis revealed that the powdered and roasted leaves exhibited competitive inhibition. At pH 6.0 at 37ºC, the IC₅₀ values of the extracts from the boiled powdered or roasted leaves were 0.36 and 1.1 mg/mL, respectively. At the same condition, the IC₅₀ values of 1-DNJ, fagomine, and GAL-DNJ were 0.70 μg/mL, 0.18 mg/mL, and 2.9 mg/mL, respectively. These results suggested that in M. australis, 1-DNJ is a major inhibitor of α-glucosidase.

Abbreviations

1-DNJ: 1-deoxynojirimycin; GAL-DNJ: 2-O-α-D-galactopyranosyl-DNJ

中文翻译：

---

澳洲桑叶及其亚氨基糖叶粉对α-葡萄糖苷酶抑制作用的动力学分析。

桑叶含有亚氨基糖，例如1-deoxynojirimycin（1-DNJ），fagomine和可抑制α-葡萄糖苷酶的2 - O -α-D-吡喃半乳糖基脱氧nojirimycin（GAL-DNJ）。在这项研究中，我们量化的亚氨基糖类小桑树的叶子和麦芽糖通过α葡萄糖苷酶水解进行的动力学分析。通过LC-MS / MS，粉状叶子中1-DNJ，fagomine和GAL-DNJ的浓度分别为4.0、0.46和2.5 mg / g，而焙烤中的浓度分别为1.0、0.24和0.73 mg / g，分别表明焙烧过程降解了亚氨基糖。稳态动力学分析表明，粉状和烤制的叶子表现出竞争抑制作用。在37℃的pH 6.0下，IC ₅₀煮沸的粉末状或烤制叶的提取物的值分别为0.36和1.1 mg / mL。在相同条件下，1-DNJ，fagomine和GAL-DNJ的IC ₅₀值分别为0.70μg/ mL，0.18 mg / mL和2.9 mg / mL。这些结果表明，在澳大利亚支原体中，1-DNJ是α-葡萄糖苷酶的主要抑制剂。

缩略语

1-DNJ：1-脱氧野oji霉素；GAL-DNJ：2-O-α-D-吡喃半乳糖基-DNJ