An on-line detection system for screening small molecule inhibitors of α-Amylase and α-Glucosidase in Prunus mume

High-throughput screening of inhibitors from natural products is an efficient approach to target key enzymes in diabetes progression. In this study, an on-line detection system was established for the first time to rapidly screen inhibitors of alpha-amylase and alpha-glucosidase from Prunus mume . Among 28 identified compounds, 26 and 21 compounds showed strong inhibitory effect against alpha-amylase and alpha-glucosidase, respectively. Their inhibitory effects were validated by in vitro enzyme assay and fluorescence quenching which demonstrated that these inhibitors effectively interfered enzyme active sites. The inhibition kinetics suggested that chemical structures are of great importance for interfering the enzyme structures and their microenvironment polarity. Among evaluated compounds, isorhamnetin-3-O-glucoside (19) showed the strongest binding activities to alpha-amylase and alpha-glucosidase (6.34 x 10(6).nmol(-1) and 6.28 x 10(6).nmol(-1) , respectively) by the on-line detection system. Its IC50 values were 0.16 +/- 0.06 and 0.09 +/- 0.01 mu M against alpha-amylase and alpha-glucosidase, respectively. 19 gave a much higher K-i for alpha-amylase (0.1307 mM) than alpha-glucosidase (0.0063 mM), indicating its selectivity towards alpha-glucosidase. This reported method was rapid and reliable to identify prototype inhibitors against key enzymes in diabetes, and thus might serve as a general platform to screen enzyme inhibitors from natural products. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

The study established an online detection system to rapidly screen inhibitors of alpha-amylase and alpha-glucosidase from Prunus mume. Among 28 identified compounds, their inhibitory effects were validated using enzyme assays and fluorescence quenching, demonstrating interference with enzyme active sites. Isorhamnetin-3-O-glucoside showed strong binding activities to the enzymes and selectivity towards alpha-glucosidase.