Two novel abietane norditerpenoids with anti-inflammatory properties from the roots of Salvia miltiorrhiza var. alba

Salvialba acid (1) with a novel abietane norditerpenoid skeleton and 2-hydroxydihydrotanshinone I (2), a new abietane norditerpenoid, were isolated from Salvia miltiorrhiza var. alba. Their structures were elucidated by spectroscopic analysis and X-ray diffraction. The absolute configuration of 1 was determined by an electronic circular dichroism (ECD) experiment and TDDFT ECD computations. A possible biosynthesis pathway is proposed for 1. Compounds 1 and 2 were demonstrated to have anti-inflammatory effects on vascular inflammation induced by TNF-α in human aortic endothelial cells (HAECs).