Design, synthesis and cytotoxicity of a new series of isoxazolidines derived from substituted chalcones.

A new series of isomeric isoxazolidin-3-yl-3-phosphonates were synthesised from N-methyl-C-diethoxyphosphorylnitrone and substituted chalcones. The respective isoxazolidin-3-yl-3-phosphonic acids were obtained from phosphonates via dealkylation procedure using trimethylsilyl bromide. Selected phosphonates and their respective phosphonic acids were screened for their cytotoxic activity to HeLa and K562 cells with IC(50) in the 0.1-0.3mM range.