Abstract

Essential oils from fresh leaves of Sclerocarya birrea (A. Rich.) Hochst. were extracted by steam distillation. The oil yield from plant collected during the hot season (February) was 0.10±0.02 and 0.24±0.01% from plant collected during the cold season (August). GC/FID and GC/MS analysis allowed us to identify a total of 49 compounds, representing 98% of the hydrodistillate. The oils contained about 96% sesquiterpenes among which 38±0.034% of 7-epi-α-selinene during the hot season and 51.7±0.12% of 7-epi-α- selinene during the cold.The main components of the oil from the hot period were 7-epi-α-selinene (38±0.03%), α-muurolene (25±0.03%), valencene (17±0.06%), β-selinene (4.3±0.01), β-caryophyllene(3.2±0.02) allo-aromadendrene-epoxide (1.5±0.03) and 14-hydrox-α-humulene (1.5±0.03). The essential oil from the cold season was characterized by 7-epi-α-selinene(51.7±0.12%), β-selinene (15.1±0.2%), valencene (12.9±0.05%), α-selinene (8.1±0.03) andβ-caryophyllene (1.8±0.02%). This is the first report of these components in the essential oil of Sclerocarya birrea.

Key words: Sclerocarya birrea (A. Rich.), essential oils, seasonal variation, 7-epi-α-selinene, α-muurolene, valencene, β-selinene.