Comparative Study of the Chemical Constituents of Bitter Kola (Garcinia Kola) and Cola Nut (Cola Acuminata) Seeds Extracts

, kola, isolation, purification, chromatography.

Abstract

Powdered form of the dried seeds of Garcinia kola and Cola acuminata were separately cold extracted with dichloromethane (DCM). Phytochemical screening of the DCM extracts of the seeds showed the presence of alkaloids, saponins, flavonoids, tannins, steroids and glycosides. The study also revealed the presence of terpenoids in G. kola which was apparently absent in C. acuminata. The chemical constituents were investigated using Thin Layer Chromatography (TLC) while Isolation and purification of the major constituents of the two seeds were carried out using Column Chromatography and Preparative Thin Layer Chromatography. The FT-IR analyses revealed O-H stretching vibration of an alcohol at 3427 cm-1, C=O stretching of an ester at 1703 cm-1, N-H stretch of amide at 3111 cm-1 in G. kola isolate and the O-H stretching band of an alcohol at 3346 cm-1, the C=C stretching of an alkene at 1685 cm1 and aliphatic C-H stretching at 2924 cm-1 in C. acuminata. The compounds identified from G. kola through the NIST data are as follows: caffeine (RT=13.000, 31.41%), 9-octadecenoic acid, (E)- (RT=14.204, 4.42%), 9-octadecenamide, (Z)- (RT=16.120, 8.89%), Phthalic acid, di (2-propylpentyl) ester (RT=16.919, 6.37%), Beta-amyrin (olean-12-en-3-ol) (RT=17.525, 24.53%) and Alpha-amyrin (RT=18.744, 21.97%) while C. acuminata identified n-hexadecanoic acid (RT=12.871, 32.02%), 9- octadecenoic acid, (E) - (RT=14.190, 28.94%), 9-octadecenamide (Z) - (RT=16.427, 1.65%), and phthalic acid, di (2-propylpentyl) ester (RT=16.918, 19.09%).