Abstract:In order to understand the chemical constituents of bran shell of Coix lachryma-jobi, fifteen compounds were isolated from ethyl acetate fraction of ethanol extract by using various chromatographic methods. Based on their spectroscopic data, their structures were isolated as p-coumaric acid (1), p-coumaric acid methyl ester (2), (E)-2-hydroxyethyl-3-(4-hydroxyphenyl) acrylate (3), caffeic acid methyl ester (4), methyl (E)-3-(4-hydroxy-3-methoxyphenyl) acrylate (5), (E)-3-(4-methoxyphenyl)acrylic acid (6), 2,3-dihydroxy-1-(4-hydroxy-3-methoxyphenyl)propan-1-one (7), 2,3-dihydroxy-1-(4-hydroxy-3,5-dimethoxyphenyl)-1-propanone (8), p-hydro-xybenzoic acid (9), 3-hydroxy-4-methoxybenzoic acid (10), 1,3,5-trimethoxybenzene (11), methyl (3-hydroxy-2-oxo-2,3-dihydroindol-3-yl)-acetate (12), allantoin (13), 2-(2-hydroxyethyl)-3-methylfumaric acid (14) and 9-octadecenoic acid (15). The compounds 3, 7, 12, 13 and 14 were isolated from coix for the first time. The compounds 1, 2, 9, 10 and 11 had significant inhibitory activity on seed germination.