Chemical compositions and mosquito repellency of essential oils from three Tanzanian artabotrys species

The investigation whoso results mo reported in this dissertation Involved the essential oil from different plant parts of three Tanzanian Artabotrys species A stoltil, A hexapetalus and A. rupestris, The oil content of the loaves, stein and root harks <f| genus Artabotrys, was determined. The hydrodistillation results indicated the root and stem barks from Artabotrys stolzii contained highest amount of oil compared to the other parts of three plant species. GC-MS analysis indicated caryophellene oxide, cadinol, (-)-spathulenol and 7-methyl-4-methylene-l-(l-methylethyl)-naphthalcno to be the major constituents of several oil fractions of Artabotrys species. Furthermore, the leaves of Artabotrys hexapetalus were found to exhibit strong repellenoy activity with RCso = 0.181 10’4 mg/cm2 and 0.279x1 O’4 mg/cm2 for the first and the second fractions, respectively against female Anopheles gambiae mosquitoes. The repellency activity of leaves essential oil was significantly higher than other samples but less than that of the standard citronella oil used (RC50 * 0.041x10' mg/cm‘). Other oil fractions showed weak repellency activity ranging from RCso - 1.032x10 mg/cm2 to 74.747x10"4 mg/cm2.