The analytical potential of tri-n-butyl phosphate (TBP) as impregnant in the thin-layer chromatographic separation of mixtures of amines, phenols, or metal ions has been investigated. Silica gel impregnated with 0.001 M TBP as stationary phase and an aqueous micellar solution (0.01 M) of CTAB, a cationic surfactant, as mobile phase was found to be the best chromatographic system for achieving i...

The mechanism of reduction of p-nitrosophenol (pNSP) catalyzed by horse liver alcohol dehydrogenase (HADH) and human a-alcohol dehydrogenase (a-ADH) has been compared in transient and steady-state experiments. Our results indicate that pNSP reduction catalyzed by these two ADH proceeds by different mechanisms. In one mechanism, shown by Equation 1, pNSP is reduced to p-aminophenol (PAP) via tw...

Neuromelanin (NM) is produced in dopaminergic neurons of the substantia nigra (SN) and in noradrenergic neurons of the locus coeruleus (LC). The synthesis of NM in those neurons is a component of brain aging and there is the evidence that this pigment can be involved in the pathogenesis of neurodegenerative diseases such as Parkinson's disease. NM is believed to derive from the oxidative polyme...

This study focused on the development of a sensitive enzymatic biosensor for the determination of pirimicarb pesticide based on the immobilization of laccase on composite carbon paste electrodes. Multi-walled carbon nanotubes (MWCNTs) paste electrode modified by dispersion of laccase (3%, w/w) within the optimum composite matrix (60:40%, w/w, MWCNTs and paraffin binder) showed the best performa...

In this study, various concentrations of caffeic acid (CA) were used to synthesize gold nanoparticles (CA-AuNPs) in order to evaluate their catalytic activity in the 4-nitrophenol reduction reaction. To facilitate catalytic activity, caffeic acid was removed by centrifugation after synthesizing CA-AuNPs. The catalytic activity of CA-AuNPs was compared with that of centrifuged CA-AuNPs (cf-CA-Au...

The biological action ofN-acetyl-p-aminophenol - paracetamol (acetaminophen) has been demonstrated to involve different mechanisms and is still not clear. Hydrogen sulfide (H2S) has been shown to play an important role in many physiological and pathological processes including nociception. The interaction between acetaminophen and endogenous H2S is unknown. Twenty four female CBA strain mice we...

Hydrolysis of paracetamol in acidic media was studied using electrochemical technique in different reaction temperatures. Based on the fact that both paracetamol (PAR) and its hydrolyzed product, p-aminophenol (PAP) are both electroactive and their voltammetric peaks do not overlap, differential pulse voltammetry was used for the determination of the remained PAR concentration in the reaction v...