Abstract

ANTIOXIDANT ACTIVITY OF ESSNTIAL OIL OF MATURE BULB OF ALLIUM CEPA L. FROM PAKISTAN

Zafar Iqbal, Amna Ashraf, Anam Touseef, Faiza Farman, Anam Asghar, Amran Waheed

Abstract

Essential oil of allium cepa mature bulb was extracted through hydrodistillation followed by extraction with n-hexane and drying with sodium sulfate anhydrous. Dried clear oil was stored in a well tight amber color container at 4⁰C in the refrigerator. Gas chromatographymass spectrometry study of the essential oil was performed to determine the chemical constituents. Eleven constituents were identified and major constituents were methyl 5-methylfuryl sulfide (23.93%), dipropyl trisulfide (17.06%), diehyl sulfide (8.81%), allyl(but-3-enyl) sulfide (8.16%), 1-allyl-3-propyl trisulfide (8.07%). The antioxidant activity of the essential oil was measured by using DPPH and ascorbic acid as standard. The maximum antioxidant activity of the essential oil was 51.79% with 100 mg/ml while the antioxidant activity of ascorbic acid with similar concentration was 99.67%. The essential oil has specified strong pungent aroma containing mercaptanes. Antioxidants prevent free radical induced tissue damage by preventing the formation of radicals, scavenging them, or by promoting their decomposition. Synthetic antioxidants are recently reported to be dangerous to human health. Antioxidants obtained from natural resources are better for human health as they are less harmful.

Keywords: Alium Cepa L, Essential oil, Chemical Constituents, Methyl 5-methyl furyl sulfide, Antioxidant.