Thesis (M.Sc.)--Chulalongkorn University, 1997

The preliminary bioassay results of the leaves of piper betle linn. indicated that the ethanol crude extract exhibited cytotoxicity activity against brine shrimp (Artemia salina Linnaeus). Ethanol crude extract was separated to eight fractions and its chloroform fraction revealed the most biological activity. Fractionation of crude chloroform extract using column chromatography led to the isolation of ten substances. By means of physical properties, and spectroscopic data, the structures of compounds were elucidated. They were found to be 1) a mixture of 2, 6-dimethyl cyclohexanol and 5, 6, 7, 7A-tetrahydro-4, 4, 7A-trimethyl-2 (4H)-benzofuranone, 2) a mixture of straight long chain alcohols (C17-C33), 3) a mixture of straight long chain esters, 4) lupeol, 5) a mixture of straight long chain alcohol (C21, C23), 6) 2-propenyl hexanoate, 7) friedelan-3beta-ol, 8) chavibetol, 9) a mixture of steroids (campesterol, stigmasterol and beta-sitosterol), and 10) allylpyrocatechol. The bioassay results indicated that chavibetol and allylpyrocatechol exhibited cytotoxicity activity against brine shrimp (Artemia salina Linnaeus) with LC50 values of 2.55 and 16.36 microg./ml at 24 hours, respectively. In addition, fractionation of crude butanol extract led to the isolation of six groups of substances.