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; Yunxia Zhang; Xinqi Hao; Congkui Tian; Maoping Song; Xiaomeng Liu

doi:10.3389/fchem.2021.736070

Aspulvinones Suppress Postprandial Hyperglycemia as Potent α-Glucosidase Inhibitors From Aspergillus terreus ASM-1

Front Chem. 2021 Aug 17:9:736070. doi: 10.3389/fchem.2021.736070. eCollection 2021.

Authors

Changjing Wu^{1

2

3}, Xiang Cui¹, Luzhen Sun¹, Jiajia Lu¹, Feng Li¹, Minghui Song¹, Yunxia Zhang¹, Xinqi Hao², Congkui Tian³, Maoping Song², Xiaomeng Liu^{1

4}

Affiliations

¹ College of Life Sciences and Agronomy, Zhoukou Normal University, Zhoukou, China.
² College of Chemistry and Molecular Engineering, Zhengzhou University, Zhengzhou, China.
³ Wuling Mountain Institute of Natural Medicine, Hubei Minzu University, Enshi, China.
⁴ College of Public Health, Xinxiang Medical University, Xinxiang, China.

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 IC₅₀ 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.

Keywords: Aspergillus terreus; aspulvinone; secondary metabolites; structure elucidation; α-glucosidase inhibitory effect.