Phytochemical and Anti-Microbial Analysis of the Leaves of Cola Gigantea (Sterculiaceae)
C.T. Onyema, V.I.E Ajiwe

Abstract
Phytochemical and antimicrobial analyses were carried out on the purified leaves extract of Cola gigantea. The Harbone method was used in the extraction and the extract separated using a combination of column chromatography and preparative thin layer chromatography resulting in the isolation of two fractions with Rf values of 0.4467 and 0.7067 for leaves fractions 1 and 2 respectively. The isolated fractions were subjected to structural elucidation using the combination of appropriate spectroscopic instruments; FTIR, UV-Visible, GCMS, H1 and C13- NMR which gave rise to the following suggested compounds; 1,2-benzenedicarboxylic acid,dioctyldodecanoic acid, 2-propenoic acid, 2-methyl ethenyl ester and 1,2-benzene dicarboxylic acid, diisooctyl ester,2- hydroxy cyclo pentadecanone found in leaves fractions 1 and 2 respectively. Results of the phytochemical analysis showed the presence of some secondary metabolites such as Alkaloids, Carbohydrates, Cardiac glycosides, flavonoids, steroids, tannin, terpenoids in various concentrations while cyanogenic glycosides and saponin were conspicuously absent. The values of Mineral elements; Cd (0.40mg/g), As (0.03mg/g), Cr (0.90mg/g), Co (0.43mg/g), Fe (0.04mg/g) etc in the leaves all fell below the WHO recommendations thus showing its overall safety for therapeutic purposes. The antimicrobial analyses (the antifungal and anti bacterial analyses) using the Punched Agar diffusion method was carried out on the two isolated fractions comparatively with a standard drug cipromax fort (a broad spectrum antibiotic). A total of fourteen test organisms consisting of eleven bacteria strains and three fungi were used with the leaves fractions being active on all the test organisms given their average diameter zones of inhibition which ranged between 10mm and 28mm. Comparatively, the standard drug cipromax fort was of better antimicrobial effect than the leaves extracts. However, these fractions can serve as antimicrobial to diseases caused by these test organisms as acclaimed by ethnomedical practitioners given their MIC, MBC and MFC results.

Full Text: PDF