Aspulvinones Suppress Postprandial Hyperglycemia as Potent α-Glucosidase Inhibitors From Aspergillus terreus ASM-1
Changjing Wu, Xiang Cui, Luzhen Sun, Jiajia Lu, Feng Li, Minghui Song, Minghui Song, Yunxia Zhang, Xin‐Qi Hao, Congkui Tian, Mao‐Ping Song, Mao‐Ping Song, Xiaomeng Liu
Abstract
Chemical investigation of Aspergillus terreus ASM-1 fermentation resulted in the isolation of three new prenylated aspulvinones V–X ( 1 – 3 ), together with the previously reported analogs, aspulvinone H ( 4 ), J-CR ( 5 ), and R ( 6 ). Their structures were elucidated by various spectroscopic methods including HRESIMS and NMR, and the absolute configurations of 2 and 3 were determined by ECD comparison. Compounds 1 – 6 were evaluated for α-glucosidase inhibitory effects with acarbose as positive control. As a result, compounds 1 and 4 exhibited potent α-glucosidase inhibitory activities with IC 50 values of 2.2 and 4.6 µM in mixed-type manners. The thermodynamic constants recognized the interaction between inhibitors and α-glucosidase was hydrophobic force-driven spontaneous exothermic reaction. The CD spectra also indicate that the compounds 1 and 4 changed the enzyme conformation. Furthermore, compound 4 significantly suppressed the increases in postprandial blood glucose levels in the C57BL/6J mice.