Abstract

COMPARATIVE STUDY ON ANTIOXIDANT ACTIVITY OF ESSENTIAL OILS FROM POGOSTEMON BENGHALENSIS (BURM.F.) KUNTZE. AND P.CABLIN (BLANCO) BENTH

Pradeep D. P.* and K. Murugan

Abstract

Essential oils (Eos) are complex mixtures of volatile lipophiliccomponents and are obtained from leaf, twigs, fruits, flowers of higherplants. These oils are isolated commonly through hydrodistillation.Pogostemon species are well known for their essential oils andtherapeutic values. Chemical composition and antioxidant activity ofEos from two species viz. Pogostemon benghalensis and P. cablinwere evaluated. Essential oil from both species was extracted byhydrodistillation using Clevenger type apparatus. The essential oilobtained was subjected to GC-Fid analysis followed by GC-MS. Theantioxidant activity was studied using DPPH, ABTS, FRAP, metalchelating, hydrogen peroxide, super oxide radical, reducing power,hydroxyl radical scavenging assays using ascorbic acid and butylated hydoxytoluene asstandards. 36 to 41 compounds were identified from the essential oil of Pogostemon species.α-Cadinol (35.78%) and patchouli alcohol (34.85%) were the major components in these oils.In addition to these compounds 1,8 cineole, aromadendrene, β-patchoulene, α-caryophyllene,β-caryophyllene, α-patchoulene, germacrene A were identified as the other predominantcompounds. The antioxidant activity of Eos was significant when compared with standards.75.3 to 91.5% inhibition activity was noticed against various free radical scavenging assays.The Eos showed remarkable IC50 value which suggests their potency to use as a naturalantioxidant in various industries, foods and therapeutics.

Keywords: Essential oils, Pogostemon, hydrodistillation, GC-MS, ?-Cadinol, patchouli alcohol.