A cationic Zn^IIporphyrazine induces a stable parallel G-quadruplex conformation in human telomeric DNA

Abstract

A water soluble Zn(II) porphyrazine drives the conformational equilibrium of the G-quadruplex of a human telomeric sequence exclusively towards a parallel conformation upon complexation.

Tetrapyrazinoporphyrazines and their metal derivatives. Part I: Synthesis and basic structural information

“…For the macrocyclic bimetallic complexes [(M'Cl 2 )TPyz42PzM] (Scheme 31, E) in the absence of single crystal X-ray data the "py-py" coordination for the M'Cl 2 unit was confirmed by 1 H and 13 C NMR solution spectral data [56]. Besides, the species with central Zn II has been the object of detailed investigations as to its photoactivity and interaction with a G-quadruplex telomeric structure [57] and similarly for the related octacation [Me 8 TPyz42PzZn] 8+ [213], and also with B-DNA models [59]. [58] can be prepared from the mononuclear species [TPyz42PzM] either by heating with excess of Pd II or Pt II dichlorides in DMSO or in the milder experimental conditions by the reaction with an excess of the bisbenzonitrile complex [(PhCN) 2 PdCl 2 ] in CHCl 3 at ambient temperature.…”

“…Variably from batch to batch for each single species the number of clathrated water molecules can reach 15-20 for macrocyclic unit. The UV-vis and fluorescence spectral response of the most of the macrocycles and their potentialities as photosensitizers for the generation of singlet oxygen ( 1 O 2 ), of interest in photodynamic therapy [53,56,58,59,209,210,213], and as bi-multimodal anticancer drugs [57,59] were also studied. The metal free macrocycle [TPyz42PzH 2 ] (A in Scheme 31) was obtained by direct cyclotetramerization of the dinitrile precursor Pyz42, in the presence of DBU [119].…”

Dedication to Professor Claudio Ercolani on the Occasion of his 75th Birthday

“…Dedication to Professor Claudio Ercolani on the Occasion of his 75 th Birthday investigation of the structural and electronic properties and examination of possible applicative aspects of novel classes of heterocyclic phthalocyanine analogues -porphyrazines with fused highly electron-withdrawing aromatic heterocycles: 1,2,5-thiadiazoloporphyrazines, [64][65][66][67][68][69][70][71][72][73][74] 1,2,5-selenodiazolo porphyrazines, [64,72,75,76] 1,4-diazepinoporphyrazines, [77][78][79] and pyrazinoporphyrazines with pyridyl rings [80][81][82][83][84][85][86][87][88][89][90][91][92][93][94][95] or other peripheral substituents. [96][97] This research field has been reach of fruitful results also contributed at national (C. Rizzoli, Parma; M. Meneghetti, Padova; R. Rosa and G. Ricciardi, Potenza) and international level (K. M. Kadish, Houston, Texas; P. Stuzhin, Ivanovo, Russia).…”

Fluorescent cyclodextrin carriers for a water soluble ZnII pyrazinoporphyrazine octacation with photosensitizer potential

“…Multimodal anticancer potentialities emerged for some of these water soluble cationic derivatives. [9][10][11] While the presence of cationic functional groups favours solubilisation in water, high charge density inuences cellular uptake and localization in sub-cellular compartments, not always favouring membrane penetration. 12,13 Thus, the development of suitable carriers is desirable to improve the performances of the photosensitizers, for example, reducing selfassociation tendency and allowing more selective and efficient accumulation in cancer tissues.…”

“…12,15 Its ability to bind to G-quadruplex and B-DNA has also been proven in solution. 7,10,11 Although aggregation has been observed in water, RSC Advances PAPER [(CH 3 ) 8 LZn] 8+ is present in monomeric form in non-aqueous, low-donor solvents. 5 We considered cyclodextrin (CyD) derivatives as complexing agents with carrier function.…”