ABSTRACT
There are two major octadecatrienoic acids in nature, α-linolenic (ALA, 18:3n-3) and γ-linolenic (GLA, 18:3n-6) acids. Although polyunsaturated fatty acids (PUFA) of the n-3 and n-6 families have distinctly different nutritional and physiological functions, it is indeed interesting that GLA manifests effects comparable to those of ALA with some metabolic parameters such as interference with the production of 2-series prostaglandins (PG) (1,2). In addition, there are at least two other, rarer types of octadecatrienoic acids as characterized by the positional and geometrical isomers of GLA, pinolenic acid (5c,9c,12c-18:3) (3) and columbinic acid (5t,9c,12c-18:3) (4). The alteration of the position and geometry of the double bond in GLA possibly modifies the metabolic fate and consequently, the nutritional and physiological functions.
