Phytochemical investigation of ipomoea cairica for antimicrobial agents

Abstract

The emergence of new infectious diseases and the resurgence of several infections has put the people in Saharan and sub-Saharan Africa to an assiduous risk. This has created the necessity for studies directed towards the development of new alternatives for antimicrobial agents. In this study a portion of the dichloromethane/methanol (1:1, v/v) crude extract from the air dried and pulverized aerial parts of Ipomoea cairica was subjected to preliminary phytochemical screening which revealed the presence of alkaloids, sterols, flavonoids, tannins, saponins, terpenoids and phenols. Another portion of the crude extract was subjected to repeated column chromatography over silica gel leading to the identification of two compounds; Diisobutyl phthalate (53) and Friedelin (54) which were characterized and elucidated using various spectroscopic and spectrometric techniques. The crude extract and the isolated compounds were evaluated for antimicrobial activities against four bacterial strains; Escherichia coli, Salmonella typhi, Pseudomonas and Staphylococcuss aureus, and three fungal strains; Aspergillus niger, Penicillum chrysogenum and Candida albicans using well agar diffusion assay and their minimal inhibitory concentration (MIC) values determined using a 2-fold dilution technique. The crude extract exhibited good antimicrobial activities with zones of inhibitions; 20± 0.25, 26 ± 0.10, 24 ± 0.12 and 14 ± 0.05 mm for E. coli, S. typhi, P. aeruginosa and S. aureus, respectively, and the zones of inhibitions for fungal strains were as follows; 16± 0.5, 24± 0.00 and 20± 0.41 mm for A. niger, P. chrysogenum and C. albicans, respectively. The two isolated pure compounds were only tested against the four strains of bacteria and exhibited relatively weak activities: Compound (53); 8.0 ± 0.22, 4.0 ± 0.32, 6.0 ± 0.00 and 6.0 ± 0.55 mm, and Compound (54); 8.0± 0.05, 5.0± 0.50, 8.0± 0.12, 10± 0.50 mm for E. coli, S. typhi, P. aeruginosa and S. aureus, respectively. The two isolated pure compounds showed minimum inhibitory concentration (MIC) ranging from 125 to 1000 𝜇g/ml respectively.