20154-63-6Relevant academic research and scientific papers
Photochemical and pharmacological aspects of nitric oxide release from some nitrosyl ruthenium complexes entrapped in sol-gel and silicone matrices
de Lima, Renata Galv?o,Sauaia, Marilia Gama,Ferezin, Camila,Pepe, Iuri Muniz,José, Nádia Mamede,Bendhack, Lusiane M.,da Rocha, Zênis Novais,da Silva, Roberto Santana
, p. 4620 - 4624 (2008/10/09)
The entrapped [Ru(terpy)(L)NO](PF6)3, where terpy = 2,2′:6′,2″-terpyridine and L = 2,2′-bipyridine (bpy) and 3,4-diiminebenzoic acid (NH · NHq) complexes into sol-gel processed polysiloxane and silicone matrices, shows NO release characteristics when submitted to light irradiation at 355 and 532 nm, as judged by NO measurement using a NO-sensor electrode. The pharmacological properties of doped matrix showed vasodilator characteristics by visible light irradiation, which is of great interest because the target delivery system can avoid the occurrence of side effects possibly by the aquo ruthenium species. All matrices obtained showed to be amorphous materials. The scanning electron micrographs of the matrices showed irregularly shaped particles, with a broad size of 1000 μm for both matrices and homogeneous distribution.
Influence of ancillary ligand L in the nitric oxide photorelease by the [Ru(L)(tpy)NO]3+ complex and its vasodilator activity based on visible light irradiation
de Lima, Renata Galv?o,Sauaia, Marilia Gama,Bonaventura, Daniella,Tedesco, Antonio Claudio,Bendhack, Lusiane Maria,da Silva, Roberto Santana
, p. 2543 - 2549 (2008/10/09)
The photochemical and pharmacological studies of the novel [Ru(L)(tpy)NO]3+ L = bpy (2,2′-bipyridine), NH · NHq (quinonediimine) and NH2.NH2cat (o-phenylenediamine) were investigated in aqueous medium. The synthesized nitrosyl ruthenium complexes showed nitric oxide (NO) release under light irradiation at 355 nm for [Ru(L)(tpy)NO]3+ complex with quantum yield of 0.14 ± 0.02, 0.47 ± 0.03 and 0.46 ± 0.02 mol Einstein-1 for L = bpy, NH · NHq and NH2 · NH2cat, respectively, and 0.0065 ± 0.001 mol Einstein-1 for light irradiation at 532 nm for [Ru(NH · NHq)(tpy)NO]3+ complex. The photochemical pathway at 355 nm light irradiation was described as a multi-step mechanism, although at 532 nm it was better attributed to a photo-induced electron transfer. The vasorelaxation induced by NO release produced by light irradiation in visible region from physiological solution of [Ru(NH · NHq)(tpy)NO]3+ complex was evaluated and compared with sodium nitroprusside (SNP). The results showed very similar vasodilator power between both species.
Controlled nitric oxide photo-release from nitro ruthenium complexes: The vasodilator response produced by UV light irradiation
De Lima, Renata Galv?o,Sauaia, Marília Gama,Bonaventura, Daniella,Tedesco, Antonio Cláudio,Vianna Lopez, Renata Fonseca,Bendhack, Lusiane M.,Da Silva, Roberto Santana
, p. 2643 - 2650 (2008/10/09)
Preliminary pharmacological studies of various nitric oxide (NO) photo-releasing agents are reported based on the flash-photolysis studies of the nitro ruthenium complexes cis-[RuII(NO2)L(bpy) 2]+ (bpy = 2,2′-bipyridine and L = pyridine, 4-picoline and pyrazine) and [RuII(NO2)(bpy)(terpy)] + (terpy = terpyridine) in physiological medium. The net photoreactions under these conditions are two primary photoproducts, in (I) there is RuII-NO2 photoaquation, where the photoproducts are RuII-H2O plus NO2- and (II) homolytic dissociation of NO from a coordinated nitrito to derive the RuII-OH2 specie and NO. Based on photochemical processes, the nitro ruthenium complexes were incorporated in water in oil (W/O) microemulsion and used in the vasorelaxation induced experiment. Denuded rat aortas were contracted with KCl and nitro ruthenium complexes in microemulsion were added. Perfusion pressures were recorded while arteries were irradiated at 355 nm The time to reach maximum relaxation was longer for [RuII(NO2)(bpy)(terpy)] + complex (ca. 50 min, n = 6) than for cis-[Ru(NO2)L(bpy) 2]+ with L = py and 4-pic complex (ca. 28 min, n = 6) and cis-[Ru(NO2)(bpy)2 (pz)]2+ complex (ca. 24 min, n = 5).
