Cytotoxic platinum(II) intercalators that incorporate 1R,2R-diaminocyclopentane

Twelve metallointercalators of the type [Pt(IL)(AL)](2+), where A(L) is either the R,R or S,S enantiomer of 1,2-diaminocyclopentane (DACP) and IL is either 1,10-phenathroline, 4-methyl-1,10-phenanthroline, 5-methyl-1,10-phenanthroline, 4,7-dimethyl-1,10-phenanthroline, 5,6-dimethyl-1,10-phenanthroline or 3,4,7,8-tetramethyl-1,10-phenanthroline, were synthesised, characterised and the cytotoxicity to the L1210 cell line was determined. The crystal structures of PHENRRDACP and PHENSS were obtained as monoclinic with a space group of P2(1) (a/angstrom = 11.4966, b/angstrom = 6.6983, c/angstrom = 12.0235) and P2(1) (a/angstrom = 11.5777, b/angstrom = 7.0009, c/angstrom = 12.5079), respectively. The R, R enantiomer of 1,2-diaminocyclopentane (RRDACP) produced the most cytotoxic metallointercalators. The most cytotoxic metallointercalators were 56MERRDACP and 47MERRDACP with IC50 values of 0.16 and 0.17 mu M, respectively, in comparison to cisplatin (1 mu M).