Fatty acid composition of individual polar lipids extracted from the brown seaweed Padina australis

A study on fatty acid compositions of individual polar lipids extracted from the brown seaweed Padina australis collected from Saugi Island of Pangkep District Indonesia has been conducted. Total lipids were extracted from the seaweed using chemical solvents of CHCl3/MeOH (2:1). ). The glycerolipid and phospholipid compounds were isolated from the total lipids using Thin-Layer Chromatography (TLC) with a mobile phase of CHCl3/MeOH/H2O/EtOAc/IPA (5:2:1:5:5). TLC conducted further purification of SQDG with a mobile phase of CHCl3/Acetone/MeOH/H2O/HOAc (10:6:2:1:2). The purified glycerolipids and phospholipids were then converted to methyl esters using 10% HCl in MeOH. The esterified glycerolipids and phospholipids were purified by silica column with eluted by solvents of hexane/diethyl ether (85:15 by vol). Analysis of the fatty acid methyl esters was carried out using a Shimadzu GC-14A gas chromatograph (Shimadzu) equipped with an Omegawax 320 column (30 m x 0.32 mm i.d., Supelco, PA, USA). The results showed that the dominant fatty acids found from the total lipid were the saturated fatty acids, palmitic acid (29.18 wt%), and arachidonic acid (23.10 wt%), whereas the dominant fatty acid found from free fatty acid fraction are palmitic acid (39.90 wt%) and oleic acid (21.3 wt%). The fatty acid compositions of individual polar lipids showed relatively similar except for MGDG and PC, which accounted for high amounts of oleic acid (21.62 wt%) and arachidonic acid (23.10 wt%), respectively. The seaweed could be a natural source of essential fatty acid, especially MGDG and PC extracts for food supplement for human health.