De novo generation of singlet oxygen and ammine ligands by photoactivation of a platinum anticancer complex.

Yao Zhao,Ruth J Mcquitty,Fuyi Wang,Abraha Habtemariam,Nicola J Farrer,Peter J Sadler,Huilin Li,Jennifer S Butler

doi:10.1002/anie.201307505

Abstract

Worth the excitement: Highly reactive oxygen and nitrogen species are generated by photoactivation of the anticancer platinum(IV) complex trans,trans,trans-[Pt(N3 )2 (OH)2 (MA)(Py)] (MA=methylamine, Py=pyridine). Singlet oxygen is formed from the hydroxido ligands and not from dissolved oxygen, and ammine ligands are products from the conversion of azido ligands to nitrenes. Both processes can induce oxidation of guanine.

Highlights

The potential for spacial selectivity, as offered by photoactivation, together with novel excited-state chemistry and accompanying mechanisms of action make exploration of photoactivated metal chemotherapeutic complexes attractive for cancer therapy.[1]
A similar result has been reported for 1 under slightly different conditions, and for related compounds.[2a,4,5] when the reaction mixture was irradiated at 420 nm for 30 min, two new photoproducts, 1 c and 1 e, were observed by HPLC (Figure 1 B)
1 c, 1 d, and 1 e are all produced by the photoreaction of 1

Summary

Introduction

The potential for spacial selectivity, as offered by photoactivation, together with novel excited-state chemistry and accompanying mechanisms of action make exploration of photoactivated metal chemotherapeutic complexes attractive for cancer therapy.[1]. When the sample was irradiated with UVA (365 nm) for 15 min, one more species, 1 d, was found (Figure 1 C). A control experiment with 5’-GMP in the absence of 1 and UVA irradiation for 15 min showed no reaction (Figure 1 D), suggesting that 5’-GMP is stable under these conditions.

Results

Conclusion