ABSTRACT
Monoaryl of benzylphosphonic acid have been synthesized and studied as the inhibitors of penicillin acylase. These compounds were found to be effective and selective irreversible inhibitors of the enzyme. The kinetic parameters of enzyme inactivation are determined, and possible mechanism of the inhibition is discussed. These phosphonates should be useful as both penicillin acylase active site titrants and the tools for the enzyme function study. Benzylchloromethyl keton has been also prepared and it is an irreversible inhibitor of penicillin acylase.
Subject(s)
Benzyl Compounds/pharmacology , Enzyme Inhibitors/pharmacology , Escherichia coli/enzymology , Organophosphonates/pharmacology , Penicillin Amidase/antagonists & inhibitors , Phosphorus/analysis , Benzyl Compounds/chemistry , Enzyme Inhibitors/chemistry , Esters , Hydrocarbons, Chlorinated/pharmacology , Kinetics , Molecular Structure , Structure-Activity RelationshipABSTRACT
The chromatographic behaviour of some alpha-trifluoromethyl-alpha-aminoacids on L-proline- and L-hydroxyproline sorbents was studied. The retention and selectivity parameters of the separation of amino acid enantiomers on the sorbents were determined. The introduction of a CF3 [corrected] group led to an increased selectivity in the separation of amino acid enantiomers on a proline sorbent and to a decreased selectivity on a hydroxyproline sorbent.
Subject(s)
Amino Acids/isolation & purification , Adsorption , Chromatography, High Pressure Liquid , Chromatography, Ion Exchange , Copper , Copper Sulfate , Hydroxyproline/isolation & purification , Kinetics , Ligands , Proline/isolation & purificationABSTRACT
The chromatographic behaviour of some natural and modified pyrimidine bases and nucleosides on an octadecyl stationary phase was studied. The retention and selectivity parameters of the separation of the compounds studied were derived on the basis of solvophobic theory. The mechanism of base and nucleoside interactions with the surface of the hydrocarbonaceous stationary phase is discussed. The best separation is observed at pH 3.5 for the bases and at pH 4.8-5.2 for the nucleosides. An increase in the solute surface tension results in an increased selectivity of separation. When the surface tension and the ionic strength of the mobile phase are not kept constant, there are considerable deviations in retention from that predicted by solvophobic theory.
Subject(s)
Pyrimidine Nucleosides/isolation & purification , Pyrimidines/isolation & purification , Chromatography, High Pressure Liquid/methods , Hydrogen-Ion Concentration , Models, Theoretical , Solvents , Structure-Activity RelationshipABSTRACT
Pharmacokinetics of 6-azacytidine, an antitumour drug, is studied by ion-pair reversed-phase highly effective liquid chromatography. The survey of the drug elimination from blood is of a two-phase character: the first phase--with a biological half-life of 5.5 min (for rats) and 6.5 min (for rabbits); the second phase--1.2 and 2.5 h, respectively. For a 24 h period 75% of the drug is excreted unchanged in the urine.
