Spectroscopic study of in situ‐formed metallocomplexes of proton pump inhibitors in water

Abstract

Proton pump inhibitors, such as omeprazole, pantoprazole and lansoprazole, are an important group of clinically used drugs. Generally, they are considered safe without direct toxicity. Nevertheless, their long‐term use can be associated with a higher risk of some serious pathological states (e.g. amnesia and oncological and neurodegenerative states). It is well known that dysregulation of the metabolism of transition metals (especially iron ions) plays a significant role in these pathological states and that the above drugs can form complexes with metal ions. However, to the best of our knowledge, this phenomenon has not yet been described in water systems. Therefore, we studied the interaction between these drugs and transition metal ions in the surrounding water environment (water/DMSO, 99:1, v/v) by absorption spectroscopy. In the presence of Fe(III), a strong redshift was observed, and more importantly, the affinities of the drugs (represented as binding constants) were strong enough, especially in the case of omeprazole, so that the formation of a metallocomplex cannot be excluded during the explanation of their side effects.

Preparation of Tryptanthrin Derivates Bearing a Thiosemicarbazone Moiety to Inhibit SARS-CoV-2 Replication

“…Conditional constants (K values) were calculated from the absorbance changes (∆A) of tryptanthrin derivates and their complexes with Cu(II), Fe(II) and Fe(III) ions at their spectral maximum by regression analysis (Letagrop Spefo 2005 software). The details of computational model have been described and discussed by Silen et al [28], and the same method was used to analyse the binding affinity of the organic receptors for metal ions in aqueous media [29][30][31][32][33][34][35][36]. Solutions were mixed in the cuvette during the whole titration and after each addition of metal guests.…”

Targeting of the Mitochondrial TET1 Protein by Pyrrolo[3,2-b]pyrrole Chelators

“…Conditional constants (Ks) were calculated from the absorbance changes, ∆A, of compounds 1-6 at the spectral maxima of their complexes with Fe(II), using nonlinear regression analysis with the Letagrop Spefo 2.0 (Vanura, Prague, Czech Republic) software. The computational model for conditional constants (Ka) is described and discussed in detail elsewhere [78], with the same method used to study the interactions of the organic hosts with metal ions in aqueous medium [79][80][81][82]. Solutions were mixed in the cuvette during the whole titration and after every Fe(II) chelate addition.…”