Novel spacer linked bile acid–cisplatin compounds as a model for specific drug delivery, synthesis and characterization

This paper reports on new compounds, which consist of three functional parts — a transport fragment, a spacer and the biologically active compound. Cholic acid as transport fragment was linked via an alkyl spacer to a cisplatin analogue, representing the drug. The length of the alkyl chain was varied in order to investigate the influence of the distance between drug and transport fragment. Here we describe the synthesis and characterization of a series of complexes with the general formulae [PtCl(DMSO)(diamine)]Cl and [PtCl2(diamine)] (diamine=THP(CH2)nCH(CH2NH2)2 and CholCOO(CH2)nCH(CH2NH2)2, n=4, 6, 8, 11). The compounds have been identified by elemental analysis, IR and NMR measurements.