Modelling of chromatographic and electrophoretic behaviour of imidazoline and alpha adrenergic receptors ligands under different acid-base conditions.

Background And Purpose: The ligands of the imidazoline and α-adrenergic receptors are mainly imidazoline and guanidine derivatives, known as centrally-acting antihypertensives and compounds with potential use in various neurological disorders. The extent of their ionisation has a major influence on their behaviour in the different analytical systems. The main objective of this work was to compare the mechanism of chromatographic retention and electrophoretic mobility under acidic, neutral and basic conditions.

Mixed-Mode Hydrophilic Interactions/Reversed-Phase Retention Mechanism in Thin-Layer Chromatography.

We investigated the dual retention mechanism in thin-layer chromatography taking place on three stationary phases of different polarity (C-18, plain silica gel and DIOL) and using binary mobile phases composed of acetonitrile as the main component and water, or methanol as a modifier. As the test analytes, we selected a set of 12 compounds of pharmaceutical importance and considerably different chemical structure, i.e.

Novel computational approaches to retention modeling in dual hydrophilic interactions/reversed phase chromatography.

The mixed-mode chromatographic behavior was estimated for imidazoline and serotonin receptor ligands, and their related compounds on dual hydrophilic/reversed phase stationary phase. The Box-Cox transformation was used to obtain the most suitable mathematical equations which describe the mixed-mode retention. Optimal equations were found for the optimization parameter (λ): λ = -1, λ = -0.

Extending Cross Metathesis To Identify Selective HDAC Inhibitors: Synthesis, Biological Activities, and Modeling.

Dissymmetric cross metathesis of alkenes as a convergent and general synthetic strategy allowed for the preparation of a new small series of human histone deacetylases (HDAC) inhibitors. Alkenes bearing Boc-protected hydroxamic acid and benzamide and trityl-protected thiols were used to provide the zinc binding groups and were reacted with alkenes bearing aromatic cap groups. One compound was identified as a selective HDAC6 inhibitor lead.

The evaluation of short- and long-term stability studies for brimonidine in aqueous humor by DPV/BDDE method-possible application for direct assay in native samples.

A novel voltammetric method was developed for brimonidine (BRIM) determination in deproteinized aqueous humor, simplifying preparation of biological samples for analysis for stability studies. The differential pulse voltammetric (DPV) method using boron doped diamond electrode (BDDE), based on characteristic oxidation peaks, was proposed and successfully applied. The linearity range was within 5.