Thesis (M.Sc.)--Chulalongkorn University, 2000

The ground-dried rhizomes of Globba malaccensis Ridl. were extracted subsequently with suitable organic solvents including ethanol, chloroform and hexane. The chloroform crude extract was separated and purified by column chromatography, and gave four known compounds. The structures of these compounds were established on the basis of physical and chemical properties and spectroscopic evidences. The four structures were proved to be sesquiterpenoids; Isocurcumenol (1, 1.2x10 -3 % wt.by wt. of the dry plant 4 kg.), Curcumenol (2, 5.5x10 -2 % wt.by wt. of the dry plant 4 kg.) and zedoarondiol (4, 1.4x10 -3 % wt.by wt. of the dry plant 4 kg), and curcumenoid; Curcumin (3, 1.3x10 -1 % wt.by wt. fo the dry plant 4 kg). It was the first report of the x-ray crystallographic analysis of curcumenol. These four isolated compounds were tested for their inhibitory activities against cyclic AMP phosphodiesterase. The result indicated that most of tested compounds exhibited moderate to high inhibitory activities.