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

The investigation of chemical constituents of Curcuma mangga Valeton & van Zyp (Zingiberaceae) was performed on both non-volatile and volatile parts. Chromatographic separation led to the isolation of 3 compounds from non volatile part. The structure determination was accomplished by the aids of spectroscopic means and the previous data of related compound. A structure of new labdane type diterpene, 15-ethoxy-8(17), 12-labdadien-15, 16-olide was deduced through extensive 1D and 2D NMR studies. A norlabdane-type diterpene, 15,16-bisnorlabda-8(17), 11-dien-13-one was determined whilst the complete revision of 1H and 13C assignments were attained. Moreover, beta-sitosterol and stigmasterol was detected as a mixture of steroidal compounds. The volatile constituents hydrodistilled from the fresh rhizome was analysed by GC/MS. At least 30 components were determined. The major compound was monoterpene group which was accounting for 97.46% and myrcene (84.61%) appeared to be the major component followed by beta-phellandrene (6.63%) and trans-ocimene (3.85%). From antimicrobial activity examination, the essential oil exhibited broad spectrum against microorganism with strong cidal effect on Staphylococus aureus and Microsporum gypseum