익모초(Leonurus sibiricus L.)의 새로운 labdane diterpenoids 분리 및 구조 규명

Abstract

In our continuing to search for the bioactive compounds from natural source, the CH2Cl2-soluble fraction of MeOH extract aerial parts of the plant Leonurus sibiricus L. showed siginificant antioxidative activity, cell cytotoxicity, and anti-inflammatory activity in an in vitro assay. Bioassay-guided isolation of this fraction led to the purification of six new bis-spirolabdane-type diterpenoids, 3α-acetoxy-leoheteronone E (1), 3α-acetoxy-15-epileoheteronone E (2), 3α-acetoxy-leoheteronone C (3), leoheteronone F (4), 3α-acetoxy-leoheteronone A (5) and leoheteronone G (6). Their structures were determined by physical and spectrosc opic analyses. Compound 1/2 were isolated as epimeric pairs at C-15, the other compounds 3, 4, 5, and 6 were obtained in pure form. All of these compounds especially have either hydroxyl group or acetoxyl group at C-3 position, for that reason they are considered as new compounds. In vitro anti-inflammatory activity was evaluated by inhibition % of hIL-6 production in TNF-α stimulated MG-63 cell line. Compound 6, isolated from the CH2Cl2 fraction, exhibited hIL-6 inhibition activity, decreased to 66.4± 1.1%.