Commipholactam A, a cytotoxic sesquiterpenoidal lactam from Resina Commiphora

Abstract

Diverse terpenoids including a novel sesquiterpenoidal lactam, commipholactam A (1), and a structurally related new cadinane sesquiterpenoid, commiphorane H (2), a new eudesmane sesquiterpenoid, commiphorane I (4), a new guaiane sesquiterpenoid, commiphorane J (5), and two new nor-abietane diterpenoids, commiphoranes K1 and K2 (6 and 7) along with two known terpenoids (3 and 8), were isolated from Resina Commiphora. Their structures with absolute configurations were characterized by spectroscopic methods and calculated electronic circular dichroism (ECD). Notably, commipholactam A represents the first example of cadinane sesquiterpene alkaloids isolated from Resina Commiphora. Biological assessment toward human cancer cells showed that the IC₅₀ values of 1 against HepG2 and A549 cells were 21.73 μM and 128.50 μM, respectively.

Keywords: Cytotoxic activities; Diterpenoids; ECD calculations; Resina Commiphora; Sesquiterpene lactam.