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 monohydroxy‐substituted polyunsaturated fatty acids from the Swertia genus in Gentianaceae.