110458-45-2Relevant academic research and scientific papers
Influence of electron acceptors on the kinetics of metoprolol photocatalytic degradation in TiO2 suspension. A combined experimental and theoretical study
Armakovi?,Armakovi?,Fin?ur,?ibul,Vione,?etraj?i?,Abramovi?
, p. 54589 - 54604 (2015)
Metoprolol (MET) belongs to a group of frequently used β1-blockers, which often occur in waste waters. The objective of this work was to employ liquid chromatography (LC) and total organic carbon methods to study the photocatalytic degradation of MET in UV irradiated aqueous suspensions of TiO2 (Wackherr's "Oxyde de titane standard" and Degussa P25), in the presence of different electron acceptors such as molecular oxygen, hydrogen peroxide, potassium bromate, and ammonium persulfate. The degradation rates were found to be strongly influenced by the kind of electron acceptor and the type of catalyst. The optimal amount of hydrogen peroxide and potassium bromate was investigated as well. MET photocatalytic degradation was the fastest in the presence of O2 and potassium bromate with TiO2 Degussa P25, while mineralization was most efficient in the presence of molecular oxygen alone. In all investigated cases, degradation followed a pseudo-first order kinetics. Reaction intermediates of MET degradation in the presence of different electron acceptors with both catalysts were studied in detail and a number of them were indentified using LC-ESI-MS/MS. The interactions with MET of reactive radical species relevant to this study (O2?-, ?OH, BrO2?, and SO4?-) were theoretically investigated by means of density functional theory (DFT) computations.
Chemical Aspects of Metoprolol Metabolism. Asymmetric Synthesis and Absolute Configuration of the 3--1-(isopropylamino)-2-propanols, the Diastereomeric Benzylic Hydroxylation Metabolites
Shetty, H. Umesha,Nelson, Wendel L.
, p. 55 - 59 (2007/10/02)
Asymmetric synthesis of 3--1-(isopropylamino)-2-propanol (2), the benzylic hydroxylation metabolite of metoprolol (1), is described, and the absolute configurations of the diastereomers were assigned.Ketone 3, prepared in a multistep synthesis, was reduced with a complex of (2S)-(-)-2-amino-3-methyl-1,1-diphenylbutan-1-ol(9) and borane, yielding 2, with a ratio of 82:18 for the diastereomers.The absolute configurations 1'S,2S and 1'S2R were assigned for the diastereomers formed in excess on the basis of reductions on closely related alkyl phenyl ketones and the circular dichroism spectrum.Derivatization of the 1'-hydroxyl group of oxazolidinone 10 with a chiral Mosher acid chloride and the use of an HPLC procedure to resolve the resulting esters enabled us to determine the metabolic product stereoselectively for 2.In the presence of the rat liver microsomal fraction, the benzylic hydroxylation of 1 was highly product stereoselective favoring 1'R stereochemistry at the new asymmetric center in racemic 1 and in both enantiomers of 1.Determination of the stereochemistry of 2 will facilitate study of this polymorphically controlled metabolic process.
