- Comparative study on degradation of propranolol and formation of oxidation products by UV/H2O2 and UV/persulfate (PDS)
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The frequent detection of propranolol, a widely used β-blocker, in wastewater effluents and surface waters has raised serious concern, due to its adverse effects on organisms. UV/hydrogen peroxide (UV/H2O2) and UV/persulfate (UV/PDS) processes are efficient in eliminating propranolol in various waters, but the formation of oxidation products in these processes, as well as the assessment of their toxicity, has not been systematically addressed. In this study, we identified and compared transformation products of propranolol produced by hydroxyl radical (?OH) and sulfate radical (SO4?-). The electrostatic attraction enhances the reaction between SO4?- and the protonated form of propranolol, while ?OH shows non-selectivity toward both protonated and neutral propranolol species. The hydroxylation of propranolol by ?OH occurs at either amine moiety or naphthalene group while SO4?- favors the oxidation of the electron-rich naphthalene group. Further oxidation by ?OH and SO4?- results in ring-opening products. Bicarbonate and chloride exert no effect on propranolol degradation. The generation of CO3?- and Cl-containing radicals is favorable to oxidizing naphthalene group. The acute toxicity assay of Vibrio fischeri suggests that SO4?- generates more toxic products than ?OH, while CO3?- and Cl-containing radicals produce similar toxicity as SO4?-. High concentrations of bicarbonate in UV/H2O2 increase the toxicity of treated solution.
- Yang, Yi,Cao, Ying,Jiang, Jin,Lu, Xinglin,Ma, Jun,Pang, Suyan,Li, Juan,Liu, Yongze,Zhou, Yang,Guan, Chaoting
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- Removal of metoprolol by means of photo-oxidation processes
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In this study, β-blocker metoprolol was degraded by photocatalysis and photo-Fenton catalyzed by doped TiO2. The effect of two main variables was elucidated, content and type of doping cation (Fe or Cu). The catalysts were synthesized by Evaporation-Induced Self-Assembly (EISA) method and their performance was compared with typical Degussa P25. All synthesized materials were found to be mesoporous with a specific surface in the range of 121–242 m2/g, they all exhibited anatase phase, and crystallites in the range of 6–10 nm. The use of X-ray photoelectron spectroscopy (XPS) allowed to establish not only the presence of the expected Ti4+ but also Ti3+ species. Cu2+ and Fe3+ species were also identified in the doped catalysts. It was found that the addition of Cu and Fe diminished the energy band gap of synthesized TiO2, from 3.20 eV to 2.58 and 2.64, respectively. The content of Cu is directly correlated with this effect. In photocatalysis, the doping of TiO2 did not have an effect of metoprolol degradation rate. This was improved, however, approximately 60% by the synthesized TiO2 compared to Degussa P25. On the other hand, the photo-Fenton-like process catalyzed by Cu-TiO2 exhibited the highest degradation (total removal) and mineralization extent (90%), being faster than the photocatalytic process and the UV-H2O2 system. Another difference between both methods, was the amount and type of intermediates generated. These were identified by LC-MS. Photo-Fenton catalyzed by Cu/TiO2 can be considered as an effective process with high oxidative power in the metoprolol degradation.
- Avilés-García, Osmín,Brewer, Sharon,Donkor, Kingsley,Espino-Valencia, Jaime,Mendoza-Zepeda, Arisbeht,Natividad, Reyna,Romero, Rubi
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- ARYL LACTAM KINASE INHIBITORS
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The present disclosure is generally directed to compounds which can inhibit AAK1 (adaptor associated kinase 1), compositions comprising such compounds, and methods for inhibiting AAK1.
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Page/Page column 308
(2015/11/02)
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- Influence of electron acceptors on the kinetics of metoprolol photocatalytic degradation in TiO2 suspension. A combined experimental and theoretical study
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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.
- Armakovi?,Armakovi?,Fin?ur,?ibul,Vione,?etraj?i?,Abramovi?
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p. 54589 - 54604
(2015/06/30)
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- propanolamines. 1. Novel β-Blockers with Ultrashort Duration of Action
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Novel propanolamines were synthesized and investigated as potential ultrashort-acting β-adrenergic receptor blockers.Many of these analogues exhibited good potency and short duration.The N-ureidoalkyl analogue 85 (ACC-9089) has a potency equal to propranolol and a duration of action of about 21 min in the dog.It has been selected as a candidate for further clinical study.Structure-activity relationships and structure-duration relationships for these new β-blockers are also discussed.
- Kam, Sheung-Tsam,Matier, William L.,Mai, Khuong X.,Barcelon-Yang, Cynthia,Borgman, Robert J.,et al.
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p. 1007 - 1016
(2007/10/02)
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- β1-Selective adrenoceptor antagonists: Examples of the 2-[4-[3-(substituted-amino)-2-hydroxypropoxy]phenyl]imidazole class
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A series of 2-[4-[3-(substituted-amino)-2-hydroxypropoxy]phenyl]imidazoles is described. The compounds were investigated in vitro for β-adrenoceptor antagonism, and several examples were found to be selective for the β1-adrenoceptor. The structure-activity relationship exhibited by this series of compounds is discussed. (S)-2-[p-[3-[[2-(3,4-dimethoxyphenyl)ethyl]amino]-2-hydroxypropoxy]phenyl] -4-(2-thienyl)imidazole [(S)-13] was over 100 times more selective than atenolol for the β1-adrenergic receptor and has been selected for in-depth studies.
- Baldwin,Denny,Hirschmann,Freedman,Ponticello,Gross,Sweet
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p. 950 - 957
(2007/10/02)
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- Method for treating glaucoma by the topical administration of selectively metabolized beta-blocking agents
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A method for the treatment of glaucoma or lowering intraocular pressure in a mammal, involving topically administering to the eye of such mammal a selectively metabolized beta-blocking compound of the formula STR1 wherein R may be lower alkyl, lower hydroxyalkyl, lower alkynyl, aralkyl, or an ester-containing group and Ar may be substituted or unsubstituted aromatic; or a pharmaceutically acceptable salt thereof. Because of a relatively long duration of action of such compounds in ocular fluids and a relatively short duration of action in the systemic circulation, such compounds are useful for the treatment of excessive intraocular pressure without substantial systemic effects.
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- METHOD FOR TREATMENT OR PROPHYLAXIS OF CARDIAC DISORDERS
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A method for the treatment or prophylaxis of cardiac disorders in a mammal, comprising administering to such mammal a short-acting β-blocking compound of the formula: STR1 wherein X is an ester-containing group; R may be lower alkyl, aralkyl or an ester-containing group; R 1 may be lower alkyl; and Ar may be substituted or unsubstituted aromatic; or a pharmaceutically acceptable salt thereof. Novel compounds possessing short acting β-adrenergic blocking activity are also disclosed.
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- Synthesis and β-Adrenergic Blocking Activity of New Aliphatic Oxime Ethers
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New β-adrenergic blocking agents, most of which do not contain an aromatic nucleus, were synthesized.They were derived either from alkylamino-aliphatic oxime ethers, or alkylamino-aliphatic ethers.Most active among these are O-acetoxime (8; trachea pA2=7.65) and 1-isobutoxy-3-(tert-butylamino)-2-propanol (15, trachea pA2=7.49), both of which displayed bronchoselectivity (β2/β1 ratio ca. 15).The role and importance of the aromatic nucleus in this class of compounds are discussed
- Leclerc, Gerard,Bieth, Nicole,Schwartz, Jean
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p. 620 - 624
(2007/10/02)
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