Studies of naturally occurring friedelane triterpenoids as insulin sensitizers in the treatment type 2 diabetes mellitus.

Type 2 diabetes mellitus (T2DM) is a rapidly expanding public epidemic and frequently results in severe vascular complications. In an attempt to find anti-diabetic agents, we report herein on the isolation, structural elucidation and bioactivity of nine friedelane-type triterpenes (1-9) and twenty two known ones (10-31) from the root barks of Celastrus vulcanicola and Maytenus jelskii. Their structures were elucidated on the basis of spectroscopic analysis, including 1D and 2D NMR techniques. Two compounds from this series (1 and 3) exhibited increased insulin-mediated signalling, which suggests these friedelane triterpenes have potential therapeutic use in insulin resistant states.