Abstract

Water and ethanol extracts of Parkia biglobosa fruit husk were compared and analysed. Methods used were Sohxlet extraction, phytochemical screening, high power liquid chromatography (HPLC), fractionation and thin layer chromatography (TLC). Water was identified as a more efficient solvent than ethanol for the extraction of P. biglobosa fruit husk. The storage period (after harvest) of husk was not relevant to the mass of extract obtained. The extract contained tannins, flavonoids, anthraquinones, saponins, anthraquinone glycosides, and alkaloids. From the HPLC analyses, there was at least one class of alkaloids present in the aqueous extract, at least three classes of phenolic glycosides, and at least two of the same or any two different classes of phenolic acids, flavonols and/or proanthocyanidins observed. There were moderately polar components, which associated together in minimum groups of two on TLC plates. A 2:1 mixture of ethanol to water produced the high retention factors (Rf) of 0.96 and 0.67 in the extract, and 1.0 in the strong acid fraction. 2:1 ethylacetate-chloroform mobile phase mixture had the lowest Rf (0.06) as well as separation. The strong acid fraction had at least three components; the weak acid fraction had four; the basic fraction had three; while the neutral fraction had four components.

Key words: Phytochemicals, extraction, components, phenolics, fractionation.