Thesis (M.Sc.)--Chulalongkorn University, 2007

The antibacterial activity screening for dermatotis disease from various extracts of Jatropha curcas using agar well diffusion method was conducted. The CH2Cl2 extract of the leaves revealed good antibacterial activity against gram positive and gram negative bacteria including Staphylococcus auricularis, Staphylococcus aureus, Pseudomonas aeruginosa and Aeromonas hydrophila. Using biological activity as a guide, among isolated substances: a mixture of steroids, long chain alcohols and 7,2'-dihydroxy-3'-methylflavone, the latter was disclosed as the active principle revealing the highest activity against P. aeruginosa. Moreover, the hexane extract of oil and the CH2Cl2 extract of the latex displayed high antibacterial activity. According to the bioactivity results of these two extracts, the synergists of major and minor substances were expected.