Antibacterial activity of Citrus reticulata peel extracts

Citrus peels were successively extracted with hexane, chloroform and aceton e using a soxhlet extractor. The hexane and chloroform extracts were fracti onated into alcohol-soluble and alcohol-insoluble fractions. These fraction s were tested against different gram positive and gram negative bacteria. T he EtOH-soluble fraction was found to be most effective. Fractionation of E tOH-soluble fraction on silica gel column yielded three polymethoxylated fl avones, namely desmethylnobiletin, nobiletin and tangeretin. Their structur es were confirmed by UV, H-1, C-13 NMR and mass spectral studies. The findi ngs indicated a potential of these natural compounds as bio-preservatives i n food applications.