Isolation and characterization of the bioactive compounds in the stem bark of Albizia Coriaria

Abstract

In this study, Albizia coriaria was investigated for the bioactive compounds present in its stem bark. The plant was selected on the basis of its widespread use in traditional herbal medicine. The stem bark was collected from a plant of Albizia coriaria in Mukono District in June 2012. Extraction of the plant material was done with ethyl acetate, methanol and water and the bioactivity of each extract was tested against E. coli and P. aeruginosa. Separation and purification of the compounds in the most active (ethyl acetate) extract was done using a combination of column chromatography and thin layer chromatography. The compounds were identified by 1D and 2D -1H and 13C NMR techniques as well as Mass spectrometry (MS). The results of the bioactivity tests carried out in this study indicate that A. coriaria has potential anti microbial activity (Table 4.1.1). Six compounds, namely: Lupeol (1), Lupenone (2), Betulinic acid (3), Acacic acid lactone (4), (+) – Catechin (5) and Benzyl alcohol (6) were identified and characterized from the most bioactive (ethyl acetate) extract (Fig. 4.2.1g, 4.2.2g, 4.2.3f, 4.2.4f, 4.2.5g and 4.2.6d). Five of the characterized compounds have a wide range of biological activity reported in literature. This justifies the use of this plant in traditional medicine and indicates a promising potential for the development of medicinal agents from Albizia coriaria stem bark.