Mixed ligand complexes of platinum(II) and palladium(II) with cytokinin-derived compounds Bohemine and Olomoucine:: X-ray structure of [Pt(BohH+-N7)Cl3]•9/5H2O {Boh=6-(benzylamino)-2-[(3-(hydroxypropyl)-amino]-9-isopropylpurine, Bohemine}

The new square-planar Pt(II) and Pd(II) complexes with cytokinin-derived compounds Bohemine and Olomoucine, having the formulae [Pt(BohH(+))Cl3].H2O (1), [Pt(Boh)(2)Cl-2].3H(2)O (2), [Pt(Boh-H)Cl(H2O)2].H2O (3), [Pt(OloH(+))Cl-3].H2O (4), [Pd(BohH(+))Cl-3].H2O (5), [Pd(Boh)Cl-2(H2O)] (6), [Pd(Boh-H)Cl(H2O)].EtOH (7) and [Pd(OloH(+))Cl-3].H2O (8), where Boh=6(benzylamino)-2-[(3-(hydroxypropyl)amino]-9-isopropylpurine and Olo=6-(benzylamino)-2-[(2-(hydroxyethyl)amino]-9-methylpurine, have been synthesized. The complexes have been characterized by elemental analyses, IR, FAB+ mass, H-1, C-13 and Pt-195 NMR spectra, and conductivity data. The molecular structure of the complex [Pt(BohH(+)-N7)Cl-3].9/5H(2)O has been determined by an X-ray diffraction study. Results from physical studies show that both Bohemine and Olomoucine are coordinated to transition metals through the N(7) atom of purine ring in all the complexes. The prepared compounds have been tested in vitro for their possible cytotoxic activity against G-361 (human malignant melanoma), HOS (human osteogenic sarcoma), K-562 (human chronic myelogenous leukemia) and MCF-7 (human breast adenocarcinoma) cell lines and IC50 values have been also determined for ail the complexes. IC50 values estimated for the Pt(II)-Bohemine complexes (2.1-16 muM) allow us to conclude that they could find utilization in antineoplastic therapy. Thus, from a pharmacological point of view, Pt(II) complexes of Bohemine may represent compounds for a new class of antitumor drugs. (C) 2003 Elsevier Science Inc. All rights reserved.