Four new pregnane glycosides from Gymnema latifolium and their α-glucosidase and α-amylase inhibitory activities

Abstract

Four new pregnane glycosides, gymlatifosides A - D (1 − 4) and one known pregnane glycoside, verticilloside J (5) were isolated from the leaves of Gymnema latifolium Wall. ex Wight. Their chemical structures were elucidated on the basis of extensive spectroscopic methods, including 1D, 2D NMR, HR-ESI-MS, and in comparison with the reported data. All these compounds were tested for α-glucosidase and α-amylase inhibitory activities. Compound 5 exhibited the most anti α-glucosidase activity with inhibitory percentage of 37.8 ± 1.5% at the concentration of 200 μM. Compounds 1–4 showed moderate anti α-glucosidase activity with inhibitory percentage ranging from 7.0 to 30.1%. In addition, all compounds 1–5 showed moderate/weak anti α-amylase activity in the investigated test.

Graphical Abstract

Keywords:

• Gymnema latifolium
• α-glucosidase
• α-amylase
• gymlatifoside A
• gymlatifoside B
• gymlatifoside C
• gymlatifoside D

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This research is funded by Vietnam National Foundation for Science and Technology Development (NAFOSTED) under grant number 104.01-2017.25.