Synthesis and Characterization of Xylopic acid derivatives with potential ntimicrobial activity

Thumbnail Image
May, 2016
Journal Title
Journal ISSN
Volume Title
Xylopic acid was isolated from the dried fruits of Xylopia aethiopica, crystalized and characterized. The isolate was used to synthesize five novel derivatives of xylopic acid and these have been sufficiently characterized. The structure of derivatives was related to the observed trend in terms of antimicrobial activity. Base catalyzed ester formation was employed in the synthesis of the esters while direct coupling with HBTU was employed in the synthesis of the amide derivative. Deacetylation of xylopic acid was achieved by refluxing xylopic acid with 10% methanolic KOH. The structures of the derivatives were confirmed using 1H NMR, mass spectrometry and IR spectroscopy. The broth dilution method was employed in the antimicrobial assay. All the synthesized derivatives were more active than xylopic acid against the microorganisms tested (Staphylococcus aureus, Streptococcus pyrogenes, Escherichia coli, Pseudomonas aeruginosa and Candida albicans). The ester derivatives were most active with MICs of up to 160µg/mL. The benzyl amide and the ester of deacetyl xylopic acid generally exhibited a lower antimicrobial activity with MICs of up to 320µg/mL.
Dissertation submitted to the Department of Pharmaceutical Chemistry of the Faculty of Pharmacy and Pharmaceutical Sciences, KNUST in partial fulfillment of the requirements for the award of a Master of Philosophy degree in Pharmaceutical Chemistry,