Abietane diterpenoids from Dracocephalum moldavica L. and their anti-inflammatory activities in vitro

Abstract

Five undescribed abietane diterpenoids, dracocephalumoids A-E, together with six known analogues were isolated from the aqueous EtOH extract of aerial parts of Dracocephalum moldavica L.. The structures were elucidated through extensive analysis of spectroscopic data, and their absolute configurations were established by Mosher's method and time-dependent density functional theory electronic circular dichroism (TDDFT ECD) calculation. Cell-based anti-inflammatory assays displayed that dracocephalumoid A, uncinatone, trichotomone F and caryopterisoid C showed potent suppressive effects against TNF-α, IL-1β or NO production in LPS-induced RAW 264.7 cells, with IC₅₀ values ranging from 1.12 to 5.84 μM. The structure-activity relationship of these compounds was also discussed.

Keywords: Abietane diterpenoids; Anti-inflammatory activities; Dracocephalum moldavica L.; Dracocephalumoids A–E; Labiatae; Structure-activity relationship.