Antarctic red macroalgae: a source of polyunsaturated fatty acids

The n -3 and n -6 series of polyunsaturated fatty acids (PUFAs) are important for numerous metabolic functions that reduce the risk of inflammation, cancer, and heart diseases. These fatty acids (FAs) have been detected in high concentrations in some species of algae. The amount of the n -3 and n -6 PUFAs is closely associated with abiotic factors, such as solar radiation intensity, salinity, and temperature variation. However, abiotic influence on PUFA levels, along with the physiological function of these molecules in algae, remains inconclusive. In the present study, the quantities of the n -3 and n -6 in Antarctic red algae species Iridaea cordata , Palmaria decipiens , Plocamium cartilagineum , and Pyropia endiviifolia were determined. The lipids were extracted from the macroalgae according to the method followed by Bligh and Dyer ( 1959 ) and converted to methyl esters for further analysis using gas chromatography. The main n -6 PUFA identified and quantified in this study of Antarctic red algae were linoleic acid (18:2 n- 6), dihomo- γ -linolenic acid (20:3 n- 6), and arachidonic acid (20:4 n- 6). The eicosapentaenoic acid was detected at high concentrations in all species, with approximately 62.8% of total FA in P. endiviifolia , 75.4% in P. decipiens , 50.4% in I. cordata , and 20.1% in P. cartilagineum . The results corroborate those of the literature and show that PUFAs increased in red algae environments, with increased production of n -3 and n -6 PUFAs.