Molecular Basis of the Antitumor Activities of 2-Crotonyloxymethyl-2-cycloalkenones

Abstract
The antitumor activity of 2-crotonyloxymethyl-2-cyclohexenone (COMC-6) is not the result of the GSH conjugate (GSMC-6) formed inside tumor cells, as the diethyl ester prodrug form of GSMC-6 displays little antitumor activity with B16 melanotic melanoma in vitro (IC50 > 460 μM) versus COMC-6 (IC50 0.041 μM) and its five- and seven-membered ring homologues. Antitumor activity probably results from a reactive intermediate that forms during conjugation of the COMCs with intracellular GSH.