Determination of ATP and its metabolites in dietary energy supplements by capillary electrophoresis

Abstract This study aimed to develop a simple and fast capillary electrophoresis (CE) method for the simultaneous determination of adenosine triphosphate (ATP) and its metabolites in dietary energy supplements. Reverse polarity separation mode for faster separation of the three strong negatively charged analytes and capillaries with a 25 µm inner diameter was employed. At -433 V/cm field strength at background electrolyte (BGE) consist with 0.1 M tris-HCl, 0.5 mM tetradecyltrimethylammonium chloride (TTAC) as positively charged surfactant and 0.3 mg/mL hydroxypropylmethylcellulose (HPMC) to reduce the electroosmotic flow (EOF), a complete separation of the three species were achieved in less than 15 minutes. The data acquisition was conducted at a wavelength of 254 nm. Three different commercialised dietary energy supplements were analysed.

Design, Synthesis, and Biological Evaluation of Pyridazinones Containing the (2-Fluorophenyl) Piperazine Moiety as Selective MAO-B Inhibitors.

Twelve pyridazinones (T1-T12) containing the (2-fluorophenyl) piperazine moiety were designed, synthesized, and evaluated for monoamine oxidase (MAO) -A and -B inhibitory activities. T6 was found to be the most potent MAO-B inhibitor with an IC50 value of 0.013 µM, followed by T3 (IC50 = 0.039 µM). Inhibitory potency for MAO-B was more enhanced by meta bromo substitution (T6) than by para bromo substitution (T7). For para substitution, inhibitory potencies for MAO-B were as follows: -Cl (T3) > -N(CH3)2 (T12) > -OCH3 (T9) > Br (T7) > F (T5) > -CH3 (T11) > -H (T1). T6 and T3 efficiently inhibited MAO-A with IC50 values of 1.57 and 4.19 µM and had the highest selectivity indices (SIs) for MAO-B (120.8 and 107.4, respectively). T3 and T6 were found to be reversible and competitive inhibitors of MAO-B with Ki values of 0.014 and 0.0071, respectively. Moreover, T6 was less toxic to healthy fibroblast cells (L929) than T3. Molecular docking simulations with MAO binding sites returned higher docking scores for T6 and T3 with MAO-B than with MAO-A. These results suggest that T3 and T6 are selective, reversible, and competitive inhibitors of MAO-B and should be considered lead candidates for the treatment of neurodegenerative disorders like Alzheimer's disease.