THE CHEMICAL CONSTITUENTS' OF THE LEAVE ESSENTIAL OIL OF ALTERNANTHERA PUNGENS (KUNTH)

Alternanthera pungens Kunth commonly called khaki weed is from the family Amaranthaceae. It is a herbaceous perennial plant that has stems prostrate, rarely rising and about 10-50 cm long. The work was carried out due to the scarcity of information on the volatile constituents from the plant leaves despite works on the flower and other parts. The extraction of the essential oils from the dried leaves was carried out by the hydro distillation method using an all-glass Clevenger apparatus. The extracted oils were then analyzed using gas chromatography-mass spectrometry (GC-MS). A total of twelve constituents' representing 93.39% of A. Pungens oil with a yield of 0.4% (v/w) was obtained. The analysis of the GC-MS results of the leaf oil showed that it was dominated by â-ionone (42.18%) and hexahydrofarnesyl acetone (15.53%), others in trace amounts include; methyl palmitate (6.13%), 1octadecyne (4.72%), undecane (3.73%), para-mentha-1, 3, 8-triene (3.65%), isophytol (3.21%), ?cadinene (3.06%), 1, 2-dimethyl cyclooctene (3.05%), para-cymene (2.96%), phytol (2.67%) and neophytadiene (2.50%). The  common classes of compounds present in the leaves oil are aceto monocyclic monoterpenoid (42.18%), sesquiterpenoids (18.59%), hydrocarbons (11.50%), diterpenoids (8.38%), monoterpenes (6.61%) and fatty acids (6.13%).The constituents and the compositional pattern of essential oil identified from the leaves of Alternanthera pungens grown in Nigeria differ quantitatively and qualitatively from previously reported member of the genus and the presence of sesquiterpenoid as one of the major components of the oils justify the traditional use of the plants in treating pains, headaches and inflammations.