Abstract
(Z, Z, Z)-5, 9, 12-Octadecatrienoic acid and (Z, Z)-5, 9-octadecadienoic acid were isolated as components of body lipid from an unidentified species of the genus Tortonia [Astigmata : Suidasiidae]. The chemical structures were elucidated either by partial hydrogenation and subsequent GC/MS analysis of their dimethyldisulfide (DMDS) derivatives or by GC/MS analysis of their DMDS derivatives. Both are new fatty acids constituting natural products obtained from mites and are possible biosynthetic precursors of the new hydrocarbons (Z, Z, Z)-4, 8, 11-heptadecatriene and (Z, Z)-4, 8-heptadecadiene found in the same species.