The role of hydrophobic and electronic effects on the kinetic constants kcat and Km for the papain hydrolysis of a series of 22 substituted N-benzoylglycine pyridyl esters was investigated. The series studied comprises a wide variety of substituents on the N-benzoyl ring, with about a 300 000-fo...

The initial focus on characterizing novel pyrazolo[1,5-a]pyrimidin-7(4H)-one derivatives as DPP-4 inhibitors, led to a potent and selective inhibitor compound b2. This ligand exhibits potent in vitro DPP-4 inhibitory activity (IC50: 80 nM), while maintaining other key cellular parameters such as...

Various aromatic acids have been investigated as putative ligands of excitatory amino acid receptors. 3-Hydroxy-2-quinoxalinecarboxylic acid (HQC), at 1 mM, was found to antagonize the 22Na+ efflux produced in 22Na+-preloaded brain slices by N-methyl-D-aspartate and kainate. The response to glut...

The 6,7-dichloro derivative of 3-hydroxy-2-quinoxalinecarboxylic acid (diCl-HQC) is a relatively potent antagonist at the two excitatory amino acid receptor subtypes activated by N-methyl-d-aspartate (NMDA) and kainic acid. It antagonizes NMDA-induced excitation in the frog spinal cord (pA2 5.8)...

The [RuH(CO)(hqxc)(PPh3)2] complex, where hqxc is 3-hydroxy-2-quinoxalinecarboxylate, exhibits strong phosphorescence (quantum yield F = 0.0078) in the solid state giving rise to a significantly Stokes-shifted spectrum (excitation at 484 nm and emission at 687 nm); the lifetime of 6.5 μs is ver...

With the motivation of searching for highly selective ion sorbents, two new supramolecular complexes, [Zn(qc)2(H2O)2]·H2O·CH3OH (1) and [Zn(qc)2(4,4′-bpy)]n (2) have been synthesized and structurally characterized by assembly of 3-hydroxy-2-quinoxalinecarboxylic acid (Hqc) with Zn(II) at ambi...

The mid-IR and Raman spectra of 3-hydroxy-2-quinoxalinecarboxylic acid (3HQC) were recorded. These spectra were interpreted with the help of B3LYP/6-311++G(d,p) calculations and potential energy distribution (PED) analysis. As a result of the calculations, seven tautomers were determined among m...

Publisher SummaryNitrogen mustards were among the earliest drugs to be used for systemic cancer treatment. An enormous amount of information has become available on their chemistry and their mechanisms of interaction with DNA and on the spectrum of their biological activities in living systems. ...

l-para-Tyrosine was linked to ortho-hydroxyaniline, meta-hydroxyaniline and para-hydroxyaniline giving three distinct tyrosinamide molecules. The new extended amino acid derivatives were constructed to imitate, in part, the estradiol (E2, the natural female sex hormone) nucleus. The resulting ty...

The rates of hydrolysis of a series of aromatic nitrogen mustards, in aqueous solution at physiological temperature and pH, have been determined. Identical rates were observed when the hydrolysis reaction was followed either by titration of acid released or by estimation of residual alkylating a...

The enzymes involved in the activation of the O-phosphate of p-hydroxyaniline mustard in cells in culture have been studied. The results are consistent with the view that the cytotoxic action of the drug against HeLa cells is dependent on the activity of alkaline phosphatase, of the carcinoplace...

The O-phosphate, O-sulphate and O-glucuronide of p-hydroxyaniline mustard were synthesised with the objective that they might be selective anti-tumour agents for tumours with high levels of phosphatase, sulphatase and glucuronidase respectively. This paper shows that the O-phosphate and O-glucur...

The esters of Hecogenin and aza-homo-Hecogenin with N,N-bis(2-chloroethyl)aminocinnamic acid isomers have been prepared and their cytogenetic studies of structure–biological activity relationship were evaluated. The cytogenetic effects (sister chromatid exchages (SCEs) induction and proliferati...

3-Chloro-2-phenyl-isoindole-1-carbaldehyde has been prepared from N-phenylisoindolinone under Vilsmeier–Hack conditions. This electrophilic isoindole proved to be stable under the basic conditions used in the final treatment (KOH/MeOH), and for weeks under air in the solid state. Nevertheless, ...

The separation of isopropyl acetate/methyl methacrylate and methanol azeotropes is very important for recycling resources and protecting the environment. Ionic liquids (ILs) as excellent solvent are widely studied in recent years. This work investigates the feasibility for separating the isoprop...

Vapor-liquid equilibrium (VLE) data of isopropyl acetate + isopropanol, isopropyl acetate + isopropanol + 1-hexyl-3-methylimidazolium acetate ([HMIM][Ac]), isopropyl acetate + isopropanol + 1-octyl-3-methylimidazolium acetate ([OMIM][Ac]), isopropyl acetate + isopropanol +1-decyl-3-methylimidazo...

3E-1-(6-Chloro-2-methyl-4-phenylquinolin-3-yl)-3-arylprop-2-en-1-ones were synthesized and characterized by FTIR, 1H NMR, 13C NMR, HSQC, DEPT-135. In addition the compound 3E-1-(6-chloro-2-methyl-4-phenylquinolin-3-yl)-3-(2,5-dimethoxyphenyl)prop-2-en-1-one was subjected to the single crystal X-...

A method was developed to simultaneously ascertain 96 h LC50 values for seven freshwater species in a single flow through test with measured concentrations. It allows interspecific comparisons, easy determination of the most sensitive species, and cuts cost of labour, materials and chemical anal...

The indole alkaloid cyclopiazonic acid (CPA) is one of the few known nanomolar inhibitors of sarco(endo)plasmic reticulum Ca2+-ATPase (SERCA) besides the anticancer drug thapsigargin and the antiplasmoidal terpenoid artemisinin. Due to its less complex structure CPA represents an attractive lead...

A collection of 3-substituted indole derivatives was prepared using nucleophilic addition of indoles to nitrones. The compounds were then tested for their antibacterial activity against almost thirty bacterial strains representative of common human pathogens. Two types of indolic molecules inhib...