Chemical Investigations of the Essential Oils of Some Artemisia species of Ethiopia

Abstract

The compositions of the areal parts of essential oils of Artemisia abyssinica, A. absinthium (Ariti), and A. annua have been studied. The oils were examined by GC, GC/MS, 1 HNMR, and 13 CNMR techniques.The total constituents of the oils 59%, 56%, and 44% have been identified from A. abyssinica, A. absinthium(Ariti), and A. annua respectively. The major components were yomogi alcohol and artemisia alcohol acetate for A. abyssinica; camphor,davanone and chamazulene for A. absinthium and camphor for A. annua. Four compounds were isolated from A. abyssinica and A. absinthium and their structure were elucidated based on spectroscopic 13 CNMR sophisticated techniques. The identification and percentage composition of the essential oils was computed from GC and GC/MS peak areas. Qualitative analysis was based on comparison of retention times with the standard or isolated compounds and the corresponding data in the literature (2, 6, 8, 9) GC analysis of the essential oils were performed using an instrument (Model: - HP6890 GC, coupled with an auto sampler) equipped with a capillary column HP-5 (5%phenyl methyl siloxane), 30.0 m x 320 µm i.d., film thickness 0.25µm. Nitrogen was used as the carrier gas at a flow rate of 0.8 ml/min. The oven temperature was held at 50 0 C, and then programmed to 210 0 C at a rate of 3 0 C/min. The injection and FID temperatures were kept at 210 0 C and 270 0 C, respectively. The essential oils isolated by steam distillation of the areal parts of A. abyssinica, A. absinthium ( Ariti)and A. annua . Yield and color of the oils were summarized in Table-1.