Investigations on the source of gamma-linolenic acid plants

?-Linolenic acid (GLA, 18:3n-6) is the first intermediate in the bioconversion of linolenic acid (LA, 18:2n-6) to arachidonic acid (AA, 20:4n-6). GLA has proved its therapeutic value in the treatment of a wide variety of pathologies such as atopic eczema, diabetic neuropathy, rheumatoid arthritis, cancer, viral infections, osteoporosis and alcoholism. The plant family Boraginaceae is known as the most common source of GLA. Several studies have been reported on the fatty acid composition of the seed oil from different species of the Boraginaceae family. The amounts of GLA, LA and ? -linolenic acid (ALA, 18:3n-3), stearidonic acid (SDA, 18:4n-3) and erucic acid (22:1n-9) are important in respect of chemotaxonomic significance for the Boraginaceae.In this study, we investigated the fatty acid composition of the seed oils of four Anchusa L. (Boraginaceae) species [Anchusa azurea Miller var. azurea, Anchusa leptophylla Roemer & Schultes subsp. leptophylla, Anchusa arvensis (L.) Bieb. subsp. orientalis (L.) Nordh and Anchusa undulata L. subsp. hybrida (Ten.) Coutinho] collected from different localities in Turkey. Fatty acids were determined by capillary gas chromatography-mass spectrometry (GC-MS) equipped with a flame ionization detector. The seed oil content ranged from 11.20 % in A. azurea var. azurea to 22.85 % in A. leptophylla subsp. leptophylla. The fatty acid composition of the studied Anchusa taxa was uniform. The main fatty acid methyl esters were determined to be oleic (29.0-42.7 %), linoleic (12.5-32.0 %), ?-linolenic (0.3-10.8 %), erucic (3.4-17.9 %) and palmitic (4.4-16.3 %) acids. The content of GLA ranged from 3.3 % in A. leptophylla subsp. leptophylla to 6.7 % in A. arvensis subsp. orientalis. As a conclusion, these seed oils may not be considered as a new sources of GLA because of low amounts of GLA and high amounts of erucic acid in the studied Anchusa species.