In this study, methanolic extracts from the stems, leaves and flowers of Ipomoea pes-caprae that were collected in Xuan Thuy National Park were evaluated for their antibacterial and antioxidative activities, and their ability to inhibit plant growth. The DPPH free radical scavenging activity of crude methanol extracts was evaluated. | JOURNAL OF SCIENCE OF HNUE Chemical and Biological Sci. 2013 Vol. 58 No. 9 pp. 139-145 This paper is available online at http BIOLOGICAL ACTIVITY OF METHANOLIC EXTRACT DERIVED FROM Ipomoea pes-caprae L. COLLECTED IN XUAN THUY NATIONAL PARK Dao Thi Sen Dao Van Tan and Hoang Thi La Faculty of Biology Hanoi National University of Education Abstract. Ipomoea pes-caprae L. Sweet Convolvulaceae a common species in Xuan Thuy National Park Nam Dinh Province is thought to be a potential source of bioactive compounds. In this study methanolic extracts from the stems leaves and flowers of Ipomoea pes-caprae that were collected in Xuan Thuy National Park were evaluated for their antibacterial and antioxidative activities and their ability to inhibit plant growth. The DPPH free radical scavenging activity of crude methanol extracts was evaluated. The extract of flower had the highest radical scavenging activity IC50 mg mL while stem extract showed the lowest activity IC50 mg mL . Antibacterial activity was tested using the agar diffusion method and it was found that the extracts showed antibacterial activity against Bacillus subtilis and Vibrio parahaemolyticus. The stem extract showed the highest activity against V. parahaemolyticus D mm and was the only extract that inhibited E. coli growth. However no extract had an inhibitory effect on Vibrio spp. or Staphyloccus aureus. Extracts of all parts of the plant inhibited the growth of the roots of Raphanus salivus seedlings 44 - 73 . Keywords Ipomoea pes-caprae L. Sweet DPPH Antibacterial activity bioactivity. 1. Introduction Plants have been used as an important source of medicine for thousands of years. Medicinal plants are the most important source of life saving drugs for the majority of the world s population. Recently several distinct chemicals derived from plants have been used as a component in important drugs. The World Health Organization WHO has estimated that up to 80 of the human .