Preparation of aliskiren copper(II) complex and solution studies by EPR and UV-vis spectroscopies

MARÍA A. GRELA; MARÍA S. ISLAS; PATRICIA A.M. WILLIAMS; EVELINA G. FERRER

Santa Fe

Workshop; III Workshop on Magnetic Resonance NMR and EPR at the Forefront of Research; 2016

FCBC-UNL

Aliskiren (Alk) represents the first in a novel class of renin inhibitors with the potential for treatment of hypertension and related cardiovascular diseases1. With the aim of improving the pharmacological effects of different compounds by inducing favorable conformational changes or by improving their bioavailability2, our group has been working with metal complexation. Herein, we have prepared a solid complex at pH 12 and studied the interaction of the ligand and the metal at different pH values using Electron Paramagnetic Resonance (EPR) and UV-visible spectroscopies.Considering that Alk is commercially available as aliskiren hemifumarate, in a first step we have isolated aliskiren base. A solid CuAlk complex was synthesized by the addition of an aqueous solution of copper(II) nitrate to an ethanolic solution of Alk base. A violet complex, at pH 12, has been obtained and characterized by means of FTIR, EPR and electronic spectroscopies and elemental analysis as [Cu(Alk)2].2H2O.Ethanolic solutions of CuAlk were prepared at different pH values and the EPR and UV-vis spectra were registered after the variation of one unit of pH in the range between 2 and 13.