Study on anti-inflammatory activity of phenolic acids from Leucas ciliata

Abstract

The chemical constituents from Leucas ciliata belonging to Leucas genus in Lamiaceae were systematically explored by silica gel column chromatography, ODS column chromatography, Sephadex LH-20 gel column chromatography, and preparative high performance liquid chromatography, and seventeen phenolic acids were isolated. The chemical structures of the compounds were identified by their physicochemical properties, spectroscopic data, and literature. They were 4-hydroxyphenethyl ethyl succinate(1), 4-hydroxyphenethyl methyl succinate(2), 2-(4-hydroxyphenyl) ethyl acetate(3), p-hydroxyphenylethyl anisate(4), cassia cis-trans diphenylpropanoid(5), p-coumaric acid(6), 3,4-dihydroxybenzenepropionic acid methyl ester(7), caffeic acid(8), trans-p-hydroxyl ethyl cinnamate(9), methyl p-hydroxybenzeneacetate(10), 4-hydroxyphenethyl alcohol(11), syringic acid(12), vanillin(13), protocatechuic acid(14), salicylic acid(15), p-hydroxybenzaldehyde(16), and diorcinol(17). Among them, compound 1 was new, and compounds 2-10, 12, 14, and 16-17 were isolated from the plants belonging to Leucas genus for the first time. All compounds were obtained from L. ciliata for the first time. The anti-inflammatory activity of compounds 1-17 on NO production in lipopolysaccharide(LPS)-induced mouse leukemia cells of monocyte macrophage(RAW264. 7) cells was evaluated. The results showed that compounds 5, 7, and 9 exhibited significant anti-inflammatory activity, with IC50values of(10. 14±0. 36)-(21. 17±0. 11) μmol·L~(-1).