Diterpenoids from Rosmarinus officinalis L. and their nitric oxide inhibitory activity

Abstract

One icetexane diterpenoid, demethylsalvicanol (1) and four abietane diterpenoids, sageone (2), 20-deoxocamosol (3), 11,12,20-trihydroxy-abicta-8,11.13-triene (4), and 7α-tehoxyrosmanol (5) were isolated from the n-hexane layer of the leaves and twigs of Rosmarinus officinalis L. Chemical structures of compounds were identified by ESI-MS, 1D-, 2D-NMR spectra and by comparison of the spectral data in the literature. Compounds 1-5 were evaluated anti-inflammatory activity by inhibitory NO production, LPS stimulated on RAW 264.7 cells. At a concentration of 100 µM, compound 4 exhibited inhibitory percentage of 34.7±1.8 %, meanwhile compounds 1-3 and 5 showed cytotoxic effect. After dilution to concentration of 20 µM, except compound 1 and 2. compounds 3-5 did not show cytotoxic effect. Their NO inhibitory productions were ranging from 20.5±2.4 % to 26.7±1.9 %. Compounds 1, 3 and 4 have been reported for the first time from the Rosmarinus genus.