92739-63-4Relevant articles and documents
Insight into ultrasound-mediated reactive oxygen species generation by various metal-porphyrin complexes
Giuntini, Francesca,Foglietta, Federica,Marucco, Arianna M.,Troia, Adriano,Dezhkunov, Nikolai V.,Pozzoli, Alessandro,Durando, Gianni,Fenoglio, Ivana,Serpe, Loredana,Canaparo, Roberto
, p. 190 - 201 (2018)
Ultrasound is used to trigger the cytotoxicity of chemical compounds, known as sonosensitisers, in an approach called sonodynamic therapy (SDT), which is under investigation herein. The generation of reactive oxygen species (ROS) has been proposed as the main biological occurrence that leads to the cytotoxic effects, which are achieved via the synergistic action of two components: the energy-absorbing sonosensitiser and ultrasound (US), which are both harmless per se. Despite some promising results, a lack of investigation into the mechanisms behind US sonosensitiser-mediated ROS generation has prevented SDT from reaching its full potential. The aim of this work is to investigate the US-responsiveness of a variety of metal-porphyrin complexes, free-base porphyrin and Fe(III), Zn(II) and Pd(II) porphyrin, by analyzing their ROS generation under US exposure and related bio-effects. All experiments were also carried out under light exposure and the results were used as references. Our results show that porphyrin ultrasound-responsiveness depends on the metal ion present, with Zn(II) and Pd(II) porphyrin being the most efficient in generating singlet oxygen and hydroxyl radicals. ROS production efficiency is lower after ultrasound exposure than after light exposure, because of the various physico-chemical mechanisms involved in sensitiser activation. US and porphyrin-mediated ROS generation is oxygen-dependent and the activation of porphyrin by US appears to be more compatible with sonoluminescence-based photo-activation rather than a radical path process that occurs via the homolytic bond rupture of water. Notably, the cytotoxicity results reported herein, which are mirrored by ex-cellulo data, confirm that the type of ROS generation achieved by the US activation of intracellular porphyrins is pivotal to the effectiveness of cancer cell killing.
CATALYTIC CARBONYLATION CATALYSTS AND METHODS
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Page/Page column 99, (2012/12/13)
In one aspect, the present invention provides catalysts for the carbonylation of heterocycles. The inventive catalysts feature metal-ligand complexes having cationic functional groups tethered to the ligand, wherein the tethered cationic groups are associated with anionic metal carbonyl species. The invention also provides methods of using the inventive catalysts to affect the ring opening carbonylation of epoxides.
Luminescence Properties of Water-Soluble Cationic Platinum(II) and Palladium(II) Porphyrins
Blinova, I. A.,Vasil'ev, V. V.
, p. 995 - 999 (2007/10/02)
The luminescence properties Pt(II) and PD(II) complexes with meso-tetrakis(N-methylpyridyl)porphyrin (H2TMPyP4+) are studied.It is shown that metalloporphyrins in sodium dodecylsulfate micelles are monomeric.In dilute aqueous solutions, no monomer-dimer equilibrium is observed, but the addition of chloride ions gives rise to metalloporphyrin aggregation.The rate constants calculated for radiative (krad) and nonradiative (knon) deactivation of the electronically excited triplet state increase in passing from PdTMPyP4+ to PtTMPyP4+, which is explained by the heavy-atom effect.It is also shown that, during dimerization and aggregation, the value of the krad constant remains constant (for PtTMPyP4+ and PdTMPyP4+, its values are 1325 and 60 s-1, respectively), whereas the value of the knon constant increases.
