Research article

Studies on the synthesis, characterization, binding with DNA and activities of two cis-planaramineplatinum(II) complexes of the form: cis-PtL(NH₃)Cl₂ where L = 3-hydroxypyridine and 2,3-diaminopyridine

Ahmed Abdullah¹ , Fazlul Huq¹ , Ashraf Chowdhury¹ , Hasan Tayyem¹ , Philip Beale² and Keith Fisher³

¹School of Biomedical Sciences, Cumberland Campus, C42, The University of Sydney, East Street, PO Box 170, Lidcombe, NSW 1825, Australia

²RPAH, Missenden Road, Camperdown NSW, Australia

³School of Chemistry, F11, University of Sydney, NSW 2006, Australia

author email corresponding author email

BMC Chemical Biology 2006, 6:3doi:10.1186/1472-6769-6-3

Published:	13 March 2006

Abstract

Background

Cis-planaramineplatinum(II) complexes like their trans isomers are often found to be active against cancer cell lines. The present study deals with the synthesis, characterization and determination of activity of new cis-planaramineplatinum(II) complexes.

Results

Two cis-planaramineplatinum(II) complexes: cis-(3-hydroxypyridine)(ammine)dichloroplatinum(II) (code named AH3) and cis-(2,3-diaminopyridine)(ammine)dichloroplatinum(II) (code named AH7) have been prepared and characterised based on elemental analyses, IR, Raman, mass and 1H NMR spectral measurements. The interactions of the compounds with pBR322 plasmid DNA have been investigated and their activity against ovarian cancer cell lines: A2780, A2780^cisR and A2780^ZD047Rhave been determined. Like cisplatin, AH3 and AH7 are believed to form mainly monofunctional N7(G) and bifunctional intrastrand N7(G)N7(G) adducts with DNA, causing a local distortion of a DNA strand. As a result, gel mobility of the DNA changes. Both AH3 and AH7 are found to be less active than cisplatin against the three cell lines with AH3 being the more active compound of the two. The higher activity of AH3 is in line with its lower molar conductivity value corresponding to a lower degree of dissociation.

Conclusion

The differences in activity of AH3, AH7 and cisplatin against the cell lines illustrate structure-activity relationship.