2,2-DIALKYLACETIC ACIDS - A NEW CLASS OF NATURALLY-OCCURRING LIPID CONSTITUENTS

The uropygial gland waxes of the South American red-legged Seriema (Ca riama cristata (L., 1766)) were found to be composed of unbranched alc ohols and 2,2'-dialkyl-substituted acetic acids which so far have not been found in skin lipids. When used as a chemosystematic character, t he occurrence of this lipid class separates the order Cariamiformes (S eriemas) from all other avian orders hitherto investigated, especially from the Gruiformes (cranes and rails) to which they have been tentat ively attributed in the past. From the GC retention time data now avai lable for a series of 2-alkyl-substituted fatty acid methyl eaters rel ative retention time indices for other compounds may be predicted.