Functionalization of PAMAM dendrimers with [Ru(III)(edta)(H2O)](-).
The anchoring of K[Ru(III)(edta)(Cl)] on poly(amidoamine) dendrimers (PAMAM of three generations G(x)/Ru (x=0, 2 and 3)) through a peptide type bond yielded the aquo species, [Ru(III)(edta)(H2O)] on dendrimer surface, and upon NO exposure, yielded their nitrosyl analogues, G(x)/RuNO. Characterization of these compounds by elemental analysis, and a UV-vis, IR and 13C NMR spectroscopies indicated the immobilization of 4, 12 and 29 molecules of [Ru(III)(edta)(H2O)] or of the nitrosyl complex [Ru(II)(edta)NO] on the dendrimer surface for G(X)=0, 2 and 3, respectively. For each complex the electrochemical spectrum presented only one redox process with redox potential values of -0.20 and -0.32 V(vs SCE) attributed to the Ru(III)/Ru(II) and NO+/NO(0) couples in G(x)/Ru and G(x)/RuNO, respectively. The one-electron reduction of G(x)/RuNO+ generates G(x)/RuNO(0), which undergoes aquation with a k(-NO) of 2.1+/-0.7 x 10(-3)s(-1) (pH 1.0, mu=0.2 mol/L, CF3COOH/NaCF3COO, 25 degrees C). The G(x)/RuNO species induced a relaxing effect in aortic rings denuded of endothelium and exhibited in vitro assay trypanocidal activity.
Benini
P G Z
PG
Instituto de Química de São Carlos, Departamento de Química e Física Molecular, Universidade de São Paulo, Cx. Postal 780, CEP 13566-970, São Carlos, SP, Brazil.
McGarvey
B R
BR
Franco
D W
DW
D000818:Animals; D001011:Aorta / Q000187:drug effects / Q000502:physiology; D002850:Chromatography, Gel; D050091:Dendrimers; D004492:Edetic Acid; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D009569:Nitric Oxide / Q000737:chemistry / Q000493:pharmacokinetics / Q000494:pharmacology*; D010084:Oxidation-Reduction; D011073:Polyamines / Q000737:chemistry*; D011719:Pyrazines / Q000032:analysis; D051381:Rats; D017208:Rats, Wistar; D017975:Ruthenium Compounds / Q000737:chemistry / Q000493:pharmacokinetics / Q000494:pharmacology*; D013055:Spectrophotometry, Infrared; D014344:Trypanocidal Agents / Q000737:chemistry / Q000493:pharmacokinetics / Q000494:pharmacology*; D014349:Trypanosoma cruzi / Q000187:drug effects*; D014664:Vasodilation; D014867:Water
D050091:Dendrimers; C104700:PAMAM Starburst; D011073:Polyamines; D011719:Pyrazines; D017975:Ruthenium Compounds; D014344:Trypanocidal Agents; D014867:Water; D009569:Nitric Oxide; D004492:Edetic Acid