Isolation of chemical compounds and antibacterial activity from the bark of Alphonsea Cylindrica

The objectives of this study are to isolate and determine the chemical compounds from Alphonsea cylindrica bark and also to investigate their antibacterial activities. Samples were collected from Kechau Tui, Kuala Lipis, Pahang. The samples were oven dried, ground and serially extracted by maceration technique using hexane, dichloromethane and methanol. Acid base extraction was performed on the dichloromethane extract. Chemical compounds were isolated and purified by means of various chromatographic techniques. Their structures were elucidated with modern spectroscopic techniques including 1D and 2D NMR, MS, IR, UV as well as comparison with literature review. Antibacterial activity on crude extracts and pure compounds was completed using disc diffusion technique. The results of phytochemical study have led to the isolation of seven chemical compounds which were stigmasterol, kinabaline, muniranine, O-methylmoschatoline, lysicamine, atherospermidine and N-methylouregidione. Compound muniranine was successfully isolated as a new derivative of azafluorenone while stigmasterol, kinabaline, Omethylmoschatoline, lysicamine, atherospermidine and N-methylouregidione were isolated for the first time from Alphonsea species. Furthermore, the results of antibacterial activity showed that dichloromethane extract as well as compounds Omethylmoschatoline and lysicamine exhibited zone of inhibition against Staphylococcus aureus and Pseudomonas aeruginosa. Lysicamine gave minimum inhibition concentration (MIC) between 125 - 250 ug/mL compared with ampicillin, 300 ug/mL. As the conclusion, seven chemical compounds were successfully isolated and identified from Alphonsea cylindrica and two of them showed potential as antibacterial agent. For the implication, this study has potential in producing antibacterial agent from plant and supports the traditional use of Alphonsea sp. in the treatment of fever and diarrhoea.