Determination of correlation times from selective and non-selective spin-lattice relaxation rates and their use in drug-drug and drug-albumin interaction studies

The effects of the changes in sample concentration on the NMR chemical shifts and on the selective and non-selective spin-lattice relaxation rates (R1S and R1NS) of the three isomers of nitrobenzaldeyde guanyl hydrazone (NBGH) pure and with bovine serum albumin (BSA) were measured in solution. The results wereused to determine the correlation times (tauc), showing that the degree of intermolecular drug-drug association varies with the nitro group position on the ring and that this degree of association interferes with the interaction of these drugs with BSA. The results suggest that the degree of drug-drug and drug-BSA association are related to the in vitro anti-Trypanosoma cruzi activity of these compounds.

intermolecular interactions; relaxation rates; correlation times; guanyl hydrazones

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