Identification of C21 Steroidal Glycosides from Gymnema sylvestre (Retz.) and Evaluation of Their Glucose Uptake Activities.

Meiyu Liu,Guangfeng Liao,Xinzhou Yang,Rumei Lu,Tongxi Zhou,Jinyan Zhang

doi:10.3390/molecules26216549

Abstract

Gymnema sylvestre (Retz.) Schult is a multi-purpose traditional medicine that has long been used for the treatment of various diseases. To discover the potential bioactive composition of G. sylvestre, a chemical investigation was thus performed. In this research, four new C21 steroidal glycosides sylvepregosides A-D (1–4) were isolated along with four known compounds, gymnepregoside H (5), deacetylkidjoladinin (6), gymnepregoside G (7) and gymnepregoside I (8), from the ethyl acetate fraction of G. sylvestre. The structures of the new compounds were established by extensive 1D and 2D nuclear magnetic resonance (NMR) spectra with mass spectroscopy data. Compounds 1–6 promoted glucose uptake by the range of 1.10- to 2.37-fold, respectively. Compound 1 showed the most potent glucose uptake, with 1.37-fold enhancement. Further study showed that compounds 1 and 5 could promote GLUT-4 fusion with the plasma membrane in L6 cells. The result attained in this study indicated that the separation and characterization of these compounds play an important role in the research and development of new anti-diabetic drugs and pharmaceutical industry.

Highlights

Diabetes mellitus (DM) is a disease caused by lack of insulin secretion or insulin resistance, which cause the body to experience persistent hyperglycemia and long-term metabolic disorders
DM is classified into type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM), in which T2DM accounts for nearly 95% of individuals, and the number of patients is increasing year by year [1,2]
C21 steroidal glycosides isolated from Gymnema aliemifoliu [23], with two angular methyl groups CH3 -18 and CH3 -19, a secondary methyl group CH3 -21, a double bond, three oxygenated tertiary carbons, CH-3, CH-12, and CH-20, and five quaternary carbons, C-5, C-8, C-10, C-14, and C-17

Summary

Introduction

Diabetes mellitus (DM) is a disease caused by lack of insulin secretion or insulin resistance, which cause the body to experience persistent hyperglycemia and long-term metabolic disorders. Insulin resistance (IR) is one of the essential conditions in the development of type 2 diabetes mellitus, and insulin reduces blood sugar levels and improves IR by promoting glucose absorption [3]. Chinese medicine has used natural products (NPs), including TCM formulations and their extracts, to treat human diseases for thousands of years. Many Chinese herbal medicines and their active ingredients have anti-diabetic properties with minimal side effects, and are widely used in the treatment of T2DM [4]. It is of great significance to screen new effective hypoglycemic drugs from natural products through glucose uptake

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Conclusion