Structure Modification of Ethyl p-methoxycinnamate Isolated from Kaempferia galanga Linn. and Citotoxicity Assay of The Products on WiDr Cells

Abstract

Ethyl p-methoxycinnamate, major ingredient of Kaempferia galanga rhizome, have been reported not only has analgesic – anti inflammatory activities like NSAIDs which inhibited cyclooxygenase, but also inhibit tumor cell proliferation in specimen of mouse epidermis. Therefore, it will be interesting to carry out synthetic studies on the derivates of ethyl p-methoxycinnamate and searching their citotoxic activity on WiDr cell. We wish to report of structure modification on carboxyl moiety of ethyl p-methoxycinnamate and evaluation on their citotoxic activity on WiDr cell. Isolation of ethyl p-methoxycinnamate from Kaempferia galanga rhizome was carried out by percolation with ethanol 96% as solvent. Hydrolysis of ethyl p-methoxycinnamate in basic condition was performed to obtain p-methoxycinnamic acid. Preparation of some thiourea derivates of ethyl p-methoxycinnamate was carried out by microwave irradiation. Citotoxicity assay was carried out by MTT method for 48 h. Modification of carboxyl group of ethyl p-methoxycinnamate to its thiourea form could be carried out by microwave irradiation gave; (E)-3-(4-methoxyphenyl)-N-(phenylcarba- mothioyl)acrylamide (50%); (E)-3-(4-methoxyphenyl)-N-(4-methoxyphenylcarbamothi- oyl)acrylamide (26%) and (E)-3-(4-methoxyphenyl)-N-(4-methylphenylcarbamothioyl) acrylamide (54%), yield calculated for 2 step from the acid chloride. All compounds showed no citotoxic effect on WiDr cell at 48 h incubation. Keywords : ethyl p-methoxycinnamate, microwave irradiation, Kaempferia galanga, citotoxicity, WiDr cell