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Propolis is a resinous substance collected by honeybees from various plant sources. In this study, we examined the antioxidant properties of propolis from diverse geographic regions of Korea including Jeju Island. Ethanol extracts of propolis (EEP) were prepared and evaluated for their antioxidant properties by β-carotene bleaching, 1,1-diphenyl-2-picrylhydrazyl free radical-scavenging, 2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) radical cation decolorization, and ferric reducing/antioxidant power assays. Furthermore, the major constituents in EEP were identified by HPLC analysis with a photodiode array and mass spectrometric detection, and each component was quantitatively analyzed. All propolis samples except that from Hongcheon, Iksan, Aewol and Pyoseon had relatively strong antioxidant activity accompanied by high total polyphenol contents. Propolis with strong antioxidant activity contained large amounts of antioxidative compounds, such as caffeic acid, kaempferol, phenethyl caffeate and galangin. On the other hand, propolis from Jeju Island had weak antioxidant activities and had only a few compounds in propolis from other regions.Keywords: propolis, antioxidant properties, phenolics, PDA, Korea *To whom correspondence should be addressed. E-mail: mokuren@dau.ac.kr IntroductionPropolis, a natural resinous substance with a complex composition, is collected by honeybees from various sprouts, plant exudates, buds and leaves and is modified in their hives. Propolis has been used in the folk medicine since the primordial times of humanity, having acquired popularity Egyptians Arabs, Greeks, and many other civilizations (Abd El Hary and Hegazi, 2002). It has been reported to various biological activities, such as antibacterial, antiviral and antifungal (Kujumgiev et al., 1999), antihepatotoxic (Banskota et al., 2001a), antioxidant , antitumoral (Russo et al., 2004), anti-diabetic, and antihypertensive (Ahuja and Ahuja, 2011) properties. In recent decades, propolis has gained prevalent as a health drink and also has been used extensively in food and beverages, and is thought to improve human health and to prevent diseases such as inflammation, heart disease, and even cancer (Banskota et al., 2001b).Propolis usually contains a variety of chemical compounds such as polyphenols (flavonoids, phenolic acid and their esters), terpenoids, steroids and amino acids, but its composition varies qualitatively and quantitatively with the geographical region and botanical origin (Marcucci, 1995). Some of the observed biological activities might be attributable to identified chemical compositions, in particular its high polyphenol contents. Thus, propolis samples of the world, Europe, Asia and South America, have different chemical compositions (Kalogeropoulos et al., 2009;Ahn et al., 2007;Laskar et al., 2010;Silva et al., 2011). European propolis, such as Europe, North America, and non-tropic regions of Asia, contains the typical 'poplar bud' phenolics (many flavonoids and phenolic acid esters) (Bankova, 2005;Banko...

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The chemical analysis and antibacterial activity of propolis collected from some parts of Western Algeria were investigated. The ethanolic extracts of propolis (EEP) were evaluated for further investigation. The major constituents in EEP were identified by high-performance liquid chromatography (HPLC) analysis. All EEP samples were active against Gram positive bacteria (Staphylococcus aureus, Bacillus subtilis, Bacillus cereus), but no activity was found against Gram negative bacteria (Pseudomonas aeruginosa, Escherichia coli). The mean diameters of growth inhibition of the EEP ranged between 8.05 and 21.4 mm. The propolis extract obtained from Sidi bel Abbés (SFS-SBA) was more active than other samples as well as showed unique HPLC profile. These results support the idea that propolis can be a promising natural food preservative in food industry and alternative candidate for management of bacterial infections caused by drug-resistant microorganisms.