Determination and characterization of new benzimidazoles with activity against Trypanosoma cruzi by UV spectroscopy and HPLC.

This work presents the development of analytical methodologies by UV spectrophotometry and HPLC to characterize five nitroarylbenzimidazole derivatives with activity against Trypanosoma cruzi: NB, BNB, PNB, PMNB and PCNB. Both methodologies exhibit adequate repeatabilities and reproducibilities (CV<2%) and recoveries higher than 98%. The ionization constants (pK(a)), lipophilicity (log P) and effective permeability (Pe) are reported.

ESR Spin Trapping Studies of Free Radicals Generated from Nitrofuran Derivative Analogues of Nifurtimox by Electrochemical and Trypanosoma cruzi Reduction.

Electron spin resonance (ESR) spectra of radicals obtained from two analogues of the antiprotozoal drug nifurtimox by electrolytic and Trypanosoma cruzi reduction were analyzed. The electrochemistry of these compounds was studied using cyclic voltammetry. STO 3-21G ab initio and INDO molecular orbital calculations were performed to obtain the optimized geometries and spin distribution, respectively.