Oleanane Triterpenoids from the Leaves of Gymnema inodorum and Their Insulin Mimetic Activities

J Nat Prod. 2020 Apr 24;83(4):1265-1274. doi: 10.1021/acs.jnatprod.0c00051. Epub 2020 Apr 2.

Abstract

During an effort to find insulin mimetic compounds, the leaves of Gymnema inodorum were shown to have a stimulatory effect on glucose uptake in 3T3-L1 adipocyte cells. Bioassay-guided fractionation on a 70% ethanol extract of G. inodorum was applied to yield two new (1 and 2) and two known (8 and 9) oleanane triterpenoids with a methyl anthranilate moiety together with five further new oleanane triterpenoids (3-7). The chemical structures of all isolates were determined based on their spectroscopic data, including IR, UV, NMR, and mass spectrometric analysis. The isolated compounds (1-9) were determined for their stimulatory activities on glucose uptake in differentiated 3T3-L1 adipocyte cells using 2-deoxy-2-[(7-nitro-2,1,3-benzoxadiazol-4-yl)amino]-d-glucose (2-NBDG) as a fluorescent-tagged glucose probe. Three compounds (3, 5, and 9) showed stimulatory effects on the uptake of 2-NBDG in 3T3-L1 adipocyte cells. Chemicals with a methyl anthranilate moiety have been considered as crucial contributors of flavor odor in foods, and quantitative analysis showed the content of compound 8 to be 0.90 ± 0.01 mg/g of the total extract. These results suggest that the leaves of G. inodorum have the potential to be used as an antidiabetic functional food or tea.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • 3T3-L1 Cells
  • 4-Chloro-7-nitrobenzofurazan / analogs & derivatives*
  • 4-Chloro-7-nitrobenzofurazan / chemistry
  • 4-Chloro-7-nitrobenzofurazan / pharmacology
  • Animals
  • Biological Transport / drug effects
  • Cell Differentiation / drug effects
  • Deoxyglucose / analogs & derivatives*
  • Deoxyglucose / chemistry
  • Deoxyglucose / pharmacology
  • Glucose / analysis
  • Gymnema
  • Hypoglycemic Agents / chemistry
  • Hypoglycemic Agents / isolation & purification
  • Hypoglycemic Agents / pharmacology*
  • Insulin / chemistry
  • Insulin / metabolism
  • Insulin / pharmacology*
  • Mice
  • Molecular Structure
  • Oleanolic Acid / analogs & derivatives*
  • Oleanolic Acid / chemistry
  • Oleanolic Acid / isolation & purification
  • Oleanolic Acid / pharmacology
  • Plant Leaves
  • Triterpenes / chemistry
  • Triterpenes / isolation & purification
  • Triterpenes / pharmacology*

Substances

  • Hypoglycemic Agents
  • Insulin
  • Triterpenes
  • oleanane
  • Oleanolic Acid
  • Deoxyglucose
  • 4-Chloro-7-nitrobenzofurazan
  • Glucose
  • 2-(N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino)-2-deoxyglucose