Correction: Selective recognition of DNA defects by cyclometalated Ir(iii) complexes.

Correction for 'Selective recognition of DNA defects by cyclometalated Ir(iii) complexes' by David Paul Elisa Dayanidhi et al., Dalton Trans., 2019, 48, 13536-13540, DOI: .

Selective Recognition of Conformation-Specific Arylamine-DNA Adduct in Frameshift Model by [Ru(phen)2(dppz)]2.

Arylamine modification of guanine base at the G3 position in the NarI sequence (-G1G2CG3CC-) causes a frameshift mutation. Polymerase and 19F NMR studies have shown that the next flanking base at the 3' position to the G3 adduct modulates the mutational outcome because of its different conformations. Here, we have studied the interaction of the 16-mer NarI sequence (5'-CTCTCG1G2CG3CXATCAC-3') (G3 = N-acetyl-2-aminofluorene (AAF)-dG and X is either C or T) with [Ru(phen)2(dppz)]2+ (phen = 1,10-phenanthroline and dppz = dipyrido[3,2-a:2',3'-c]phenazine). Interaction studies between isomers of Ru(II) and two oligonucleotide models, viz., (a) full duplex, and (b) slipped mutagenic intermediate (SMI), have been carried out. Luminescence studies reveal that the sensitivity of Ru(II) with an adduct increases 2- to 3-fold compared to that of control in full duplex. In SMI, the sensitivity of Ru(II) varies with the next flanking base and in the order of -GAAFCC > -GAAFCT. Microscale thermophoretic data reveal that in full duplex Λ-Ru binds to -GAAFCT- by 13- and 4-fold stronger than its control and -GAAFCC-, respectively. In SMI, Δ-Ru binds to -GAAFCC- (41% stacked (S) conformer) by 3-fold while -GAAFCT- (86% major groove (B) conformer) weakens the binding of Λ-Ru by 250-fold compared to the control. The results presented here reveal that the binding of Ru(II) not only depends on conformations of the AAF-dG adduct but also is isomer-centric and might be helpful in determining the conformational heterogeneity of other covalent aryl/heterocyclic amine-DNA adducts.

Selective recognition of DNA defects by cyclometalated Ir(iii) complexes.

Selective detection of DNA defects is an attractive approach for early detection of various tumors and diseases. Ru(ii), Rh(iii) and hybrid complexes have been reported in this regard. Here, we present three heteroleptic cyclometalated Ir(iii) complexes [Ir(phpy)2(imiphen)]+(Ir-1), [Ir(phpy)2(furphen)]+(Ir-2) and [Ir(phpy)2(faqphen)]+(Ir-3) where imiphen: 2-(1H-imidazol-2-yl)-1H-imidazo[4,5-f][1,10]phenanthroline; furphen: 2-(furan-2-yl)-1H-imidazo[4,5-f][1,10]phenanthroline and faqphen: 2-(1H-imidazo[4,5-f][1,10]phenanthrolin-2-yl)anthracene-9,10-dione have been synthesized and characterized by analytical techniques. All three complexes recognize DNA defects with high selectivity as Ir-1 recognizes the abasic site opposite T and CA mismatch, Ir-2 recognizes Ab : G and Ir-3 recognizes the TT mismatch preferably. The results from this study further emphasize that the development of new luminescent probes requires fine-tuning of the ligand structure and the choice of the metal center to improve selectivity in recognition of DNA defects.