Chemical composition and antioxidant potentials of Kigelia pinnata root oil and extracts.

The chemical composition of Kigelia pinnata root oil extracted with n-hexane was analyzed by GC/GCMS. The antioxidant potential of the oil was compared to that of ethyl acetate and methanol extracts of the root. UV and IR spectroscopic techniques were used to carry out partial characterization of the oil and extracts. The free radical scavenging activity by spectrophotometric assay on the reduction of 1,1-diphenyl-2-picrylhydrazyl (DPPH) was examined while the total antioxidant activity (TAA) and relative antioxidant activity (RAA) were compared with standard antioxidant, α-tocopherol. The antioxidant activity (which correlated with the total phenolic content of the extracts) was assumed to be from the total phenolic content of the extracts. TAA was found to be higher in methanol extract (at 0.25 mg/mL). We hereby report for the first time the major component of the oil from the root of Kigelia pinnata to be elaidic acid (56.12 %). It is a reported toxicant which thereby underscores the risk in the use of the plant in traditional therapies.