Synthesis, NMR characterization and in vitro antitumor evaluation of new aminophosphonic acid diesters.

The synthesis of three novel alpha-aminophosphonic acid diesters N,N-dimethyl-[N'-methyl(diethoxyphosphonyl)-(2-furyl)]-1,3-diaminopropane, p-[N-methyl(diethoxyphosphonyl)-(2-furyl)]toluidine and p-[N-methyl(diethoxyphosphonyl)-(4-dimethylaminophenyl)]toluidine through an addition of diethyl phosphite to N,N-dimethyl-N'-furfurylidene-1,3-diaminopropane, N-furfurylidene-p-toluidine and N-(4-dimethylaminobenzylidene)-p-toluidine, respectively, is reported. The alpha-aminophosphonates have been characterized by elemental analysis, IR and NMR ((1)H, (13)C and (31)P) spectra. The compounds were tested for antiproliferative effects against 4 human leukemic cell lines, namely LAMA-84, K-562 (chronic myeloid leukemias), HL-60 (acute promyelocyte leukemia) and HL-60/Dox (multi-drug-resistant sub-line, characterized by overexpression of MRP-1 (ABC-C1)) and were found to exert concentration-dependent cytotoxic effects. A representative aminophosphonate compound was shown to induce oligonucleosomal DNA fragmentation which implies that the induction of cell death through apoptosis plays an important role for its cytotoxicity mode of action.