Studies on Compounds With Antioxidant Properties Isolated from some Aromatic Plantes

Abstract

This thesis compnses a review of literature which surveys information about the essential oils and non volatile antioxidant compounds of aromatic plants. It also gives a brief essay about different methods of extractions, and the factors effecting their chemical compositions. It comprises also some data about the reaction mechanism of antioxidants. Correlations between the essential oils and non volatile compounds and their antioxidant activities were reported. The experimental part includes information about the materials utilised in the studies, the different experimental procedures and techniques adopted which include the extraction of essential oils of E. camaldulensis var. brevirostris leaves by HD and SFE. The non volatile antioxidant compounds of the leaves were extracted using Soxhlet extraction and Super critical fluid extraction (SFE) with and without modifier addition. The antioxidant activities were determined by the thiocyanate method. The essential oils and non volatile compounds were analysed by GLC-MS, HPLC, HPLC-MS, IR, UV, HNMR and MS. The yield of essential oils of E. camaldulensis var. brevirostris leaves extracted by SFE (1.1 % fresh weight) is higher than that by HD (0.6 %). The HD and SFE extracts were subjected to GLC-MS analysis. According to GLC­ MS analysis their chemical compositions differ qualitatively and quantitatively. Ninety different components were separated and most of them were identified by GLC-MS. The SFE extract showed 81 GLC signals, the HD oil showed only 66 signals. In both extracts (HD and SFE) the main constituents were found to be P-phellandrene (8.94 % and 4.09 %), p-cymene (24.01% and 10.61% ), cryptone (12.71 % and 9.82 % ) and spathulenol (14.43 % and 13.14 % respectively). The yield of monoterpene hydrocarbons in HD oil (0.288g/1OOg fresh leaves) was slightly higher compared to that in the SFE extract (0.242g/100g fresh leaves).