Compounds from Rehmannia glutinosa and the activity to suppress α-glucosidase

Abstract

Rehmannia glutinosa was extensively used to control blood sugar in diabetes treatment in tradition Chinese medicine. In the present study, three new compounds, including an iridoid rehmannia A (1) and two ionone rehmannias B-C (7-8), together with fourteen known compounds (2-6 and 9-17), were isolated from the roots of R. glutinosa. The structures of these compounds were determined by physicochemical constants and spectral analysis (1D, 2D-NMR and MS). The effect of 1-17 on α-glucosidase activity was tested in vitro. Compounds 9, 10, and 11 (IC₅₀: 5.0, 3.1, and 6.3 mM) showed moderate activity to suppress α-glucosidase relative to acarbose (IC₅₀ = 3.0 mM). The findings provided some new insights to understand the hypoglycemic effect of R. glutinosa and the development towards the α-glucosidase inhibitor drugs.

Graphical Abstract

Keywords:

• Rehmannia glutinosa
• rehmannias A-C
• α-glucosidase inhibition

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

National Natural Science Foundation of China 82073737 the Open Fund of State Key Laboratory of Tea Plant Biology and Utilization`SKLTOF20190110 the Innovative Team of Yunnan Province No. 2019HC018.