α-Glucosidase inhibitors derived from black soybean and their inhibitory mechanisms

• DOI: 10.1016/j.lwt.2023.115502
• Publication Date: 2023-11-08T07:32:22Z
• Authors: Yu Zheng; Ruifen Zhang; Fei Huang; Lai-Hoong Cheng; Liangxiong Xu; Xuchao Jia
• Keywords: Uncompetitive inhibitor; IC50; Acarbose; Genistin

Various studies have documented the beneficial effects of black soybean extract against diabetes. However, specific active compounds responsible for these remain elusive. Here, we aimed to identify α-glucosidase inhibitors present in soybeans using affinity ultrafiltration. Seven isoflavones with inhibitory activity were identified, among which daidzein and genistein demonstrated remarkably superior compared that acarbose (IC50 = 632.5 ± 70.0 μmol/L), exhibiting IC50 values 15.7 0.3 3.2 1.2 μmol/L, respectively. An analysis structure-activity relationship revealed a negative correlation between degree glycosylation isoflavone activity. Enzyme kinetic both acted as uncompetitive α-glucosidase. Additionally, effectively suppressed intrinsic fluorescence through static quenching mechanism. The interaction or involves spontaneous formation complex, is driven by hydrophobic interactions hydrogen bonds. These findings provide valuable insights into molecular mechanisms underlying isoflavones.