Monohydroxy-substituted polyunsaturated fatty acids from Swertia japonica

Fourteen monohydroxy-substituted polyunsaturated fatty acids, including two new compounds, (9Z,12S,13E,15Z)-12-hydroxyoctadeca-9,13,15-trienoic acid (10) and (9Z,12Z,14E,16R)-16-hydroxyoctadeca-9,12,14-trienoic acid (13), and 12 known ones, i.e., 1-9, 11, 12, and 14, were isolated from the whole plants of Swertia japonica MAKINO, and characterized as the corresponding methyl esters 1a-14a. Their structures were elucidated by analysis of the corresponding spectroscopic data, and the absolute configurations of 10a and 13a were determined by the Mosher-ester method. The CD spectra (Table) of compounds 1a-14a are briefly discussed. This is the first report on the isolation of monohydroxysubstituted polyunsaturated fatty acids from the Swertia genus in Gentianaceae.