ISSN 1330-9862 original scientific paper (FTB-2366) Comparative Antioxidant and Antimicrobial Activities of Phenolic Compounds Extracted from Five Hypericum Species Mumtaz Ali 1 , Mohammad Arfan 2 , Habib Ahmad 3 , Khair Zaman 2 , Farhatullah Khan 4 and Ryszard Amarowicz 5 * 1 Department of Chemistry, University of Malakand, Chakdara, Dir, Pakistan 2 Institute of Chemical Sciences University of Peshawar, Peshawar-25120, Pakistan 3 Department of Botany, Hazara University, Mansehra, Pakistan 4 Department of Biological Sciences, Quaid-e-Azam University, Islamabad, Pakistan 5 Institute of Animal Reproduction and Food Research of the Polish Academy of Sciences, Tuwima 10, 10-747 Olsztyn, Poland Received: October 25, 2009 Accepted: April 6, 2010 Summary Phenolic compounds were extracted from five Hypericum species (H. perforatum, H. oblongifolium, H. monogynum, H. choisianum and H. dyeri Redher) using ethanol. The crude extract (called fraction 1) was then fractionated using re-extraction to water (fraction 2), ethyl acetate (fraction 3), and acetone (fraction 4). The final residue was marked as fraction 5. The content of total phenolics in the fractions ranged from 21 mg of gallic acid equiv- alents per g (fraction 5 of H. dyeri) to 100 mg of gallic acid equivalents per g (fraction 5 of H. choisianum). Phenolic compounds present in the fractions showed antioxidant and anti- radical properties investigated using DPPH radical scavenging activity, molybdate method, and reducing power. The strongest antiradical properties were noted for fraction 3 of H. choisianum (EC 50 =11.2 mg/mL), whereas the weakest was for fraction 5 of H. dyeri (EC 50 = 139.2 mg/mL). Fractions 1 and 5 of H. dyeri showed good antibacterial activity against Escherichia coli, while fractions 3–5 of H. perforatum were active against Staphylococcus au- reus and Pseudomonas aeruginosa. Fractions 1–4 of H. perforatum were found most active against Helminthosporium maydis as determined by antifungal screening. Key words: Hypericum monogynum, H. oblongifolium, H. perforatum, H. choisianum, H. dyeri, phenolic compounds, antioxidant activity, antimicrobial activities Introduction Hypericum (Guttiferae, syn. Clusiaceae) is a large genus of herbs or shrubs which grows widely in tem- perate regions. There are about 400 species of Hypericum genus and they are used as traditional medicinal plants in various parts of the world (1). Most of these species have been used for a long time for the treatment of ex- ternal wounds and gastric ulcers, and also as sedative, antiseptic, and antispasmodic herbs in folk medicine (1). In Pakistan the genus Hypericum is represented by nine species. Several studies have been published con- cerning Hypericum perforatum L., known as St. John’s wort. This species has been reported to have antidepressant, anxiolytic, antiviral, wound-healing and antimicrobial activities (1). Hypericum species have shown good antioxidant ac- tivity in vitro (2). Several studies have revealed antimi- crobial activity of various extracts of H. perforatum (3,4). The components of Hypericum perforatum chiefly respons- 205 M. ALI et al.: Antioxidant/Antimicrobial Activities of Five Hypericum sp., Food Technol. Biotechnol. 49 (2) 205–213 (2011) *Corresponding author; Phone: ++48 89 523 4627; Fax: ++48 89 524 124; E-mail: r.amarowicz@pan.olsztyn.pl