ATHUKORALA, PS2011-02-142011-02-1419991999ATHUKORALA, PS, Chemical investigation and biological activity studies of endemic gordonia species, University of Colombo UC(SCI), 1999: p.http://imsear.searo.who.int/handle/123456789/129481Dissertation: M.Phil. , University of Colombo: UC(SCI), 1999.Gordonia ceylanica (Wight) and Gordonia dassanayakei (Wadhwa et Weerasooriya) are the two endemie Gordonia species belong to family Theaceae. This thesis sescribes the chemical investigation and antibacterial / anti-fungal activity studies of the stem bark extracts of G. ceylanica and G. dassanayakei. chemical investigation of the stem bark of G. ceylanica gave eight Oleanane triterpenoids, none triterpenoidal glycoside and one steroidal compound. The stem bark od G. dassanayakei had been shown to contain seven Oleanane and one Hopane triterpeniods, one steroidal glycoside and two steroids. The natural products, 3B-acetoxy-11a,13-dihydroxyolean-12-one and 3B,11 a-diacetoxy-13-hydroxyolean-12-one isolated from both plant species have not been previously reported. these two Oleanane triterpenoides on treatment with acid resulted in a very interesting rearrangement of methyl groups. The dehydration at C-13 and the subsequent methyl group migration from C-14 to C-13, which converted the Oleanane triterpenoid to a Taraxarane type of triterpenoid. The natural products, 3B-acetoxy-28-hydroxyolean-12-ene and 3B-acetoxy-11-[2'-3'epoxyferulyloxy]-olean-13(18)-ene isolated from hot hexane, dichloromethane extracts of G ceylanica and 7,22-stigmastadiene-3-one (a-Spinasterone) and 11a,13B-dihydroxyolean-3,12-dione isolated from hot hexane extraxt of G. dassanayakei have not been previously reported...en-USUniversity of Colombo, UC(SCI): Sri Lanka HELLIS NetworkPlants, medicinalAntifungal Agents-pharmacologyPlants, Medicinal-chemistryAnti-Bacterial Agents-pharmacologyPlant Extracts-pharmacologylant Extracts-chemistryThesis