Propolis is a resinous substance produced by honey bees from various plant sources. The present research focused on the chemical and biological study of ethanolic extracts of 22 different propolis samples obtained from different geographical regions. The samples were investigated initially by high performance liquid chromatography (HPLC) in order to see if they contained any of the common marker compounds used to assess the quality of propolis. The antimicrobial activity of the propolis samples

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... was evaluated against some pathogenic microorganisms including Staphylococcus aureus, Escherichia coli, Nocardia farcinica, Mycobacterium aurum and Trypanosoma brucei. The cytotoxicity of the propolis samples was also determined. After preliminary screening, flash chromatography was used for chemical fractionation of two propolis samples S107 (Bulgaria) and S108 (China) which had been found to be active in the screens and the fractions were re-investigated for their antimicrobial and cytotoxic activity. S107(F6) and S107(F7) showed stronger antimicrobial activities than the crude samples. S107 and S108 were found to be typical temperate propolis samples containing the marker compounds caffeic acid, pinobanksin, cinnamic acid, chrysin, pinocemberin and galangin and esters of these compounds. Cytotoxicity assays were carried out on the fractions obtained from S107 and S108. Promising cytotoxic activities were found for S107(F9) reduced cell proliferation to 15% of the control against human foreskin cells. Towards the end of the study the propolis sample S263 originating from the Solomon Islands (tropical zone), was found to display promising activity against S.areus, M. aurum and T.brucei. This sample was found to be composed mainly of terpenoid components according to gas chromatography-mass spectrometry (GC-MS).