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

Abstract 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.