Investigation of antioxidant activity of nonpolar and semipolar natural compounds of the Persian Gulf Sea Cucumber (Holothuria sp.)by using Oil Stability Index (OSI) method
In this investigation, nonpolar and semipolar compounds in sea cucumber (Holothuria sp.) collected from coasts of Lengeh Port were extracted by Bligh &Dyer method. The extraction of nonpolar and semipolar natural compounds was conducted by Hexane and Ether, respectively. After condensation, the prepared samples were injected into gas chromatography machine equipped with mass spectroscopy; and mass spectra obtained, using Eight Peak reference, and Kuats index (KI) and its conformity with standard Kuats index was also assessed. The compounds in Hexane-Ether phases were identified. Based on the results, in the Hexane phase of sea cucumber issue, there were nine compounds including: 2-Octanol (5.23 %), 5-Methyl 2-Hexanol (8.05 %), 2-Nonanol (2.5%), Cyclohexasiloxane, Dodecamethyl (2.09%), 3-Hydroxystearic (1.66%), Methyl Arachidonate (20.65%), 1, 4, 8, Dodecatriene (21.71%), Oleicacid (30.27%), and 1-Dodecanol (2.52%). There were also seven compounds in the Ether phase including: Tetradecane (0.63%), Palmitoleic acid (1.23%), Palmitic acid (1.63%), Oleic acid (40.31%), Stearic acid (3.40%), Methyl Arachidonate (28.62%), and 1, 2- Benzendicarboxlic acid (2-ethyl hexyl) (2.71%). We found that in both phases the main ingredient is Oleic acid. The investigation of antioxidant activity was conducted by the OSI and Rancimat apparatus. We detected no antioxidant activity in the sea cucumber compounds