Xenobiotica 

About: Xenobiotica is an academic journal published by Informa. The journal publishes majorly in the area(s): Metabolite & Pharmacokinetics. It has an ISSN identifier of 0049-8254. Over the lifetime, 5338 publications have been published receiving 120145 citations.

'metabonomics': understanding the metabolic responses of living systems to pathophysiological stimuli via multivariate statistical analysis of biological nmr spectroscopic data

Abstract: (1999). 'Metabonomics': understanding the metabolic responses of living systems to pathophysiological stimuli via multivariate statistical analysis of biological NMR spectroscopic data. Xenobiotica: Vol. 29, No. 11, pp. 1181-1189.

Mammalian epoxide hydrases: inducible enzymes catalysing the inactivation of carcinogenic and cytotoxic metabolites derived from aromatic and olefinic compounds.

Abstract: 1. Several aromatic and olefinic compounds are converted to intermediate arene and alkene oxides by mammalian mono-oxygenases. Intermediate arene oxides rearrange non-enzymically to phenols. Arene and alkene oxides are converted by epoxide hydrases to vicinal diols and by glutathione S-epoxide conjugases to glutathione conjugates. Due to their high electrophilic reactivity, such oxiranes also bind to proteins, RNA and DNA. Mutagenic, carcinogenic and cytotoxic effects of several aromatic and olefinic compounds appear to be due to the formation of intermediate epoxides and their reaction with tissue constituents. Whether a given aromatic or olefinic compound produces such an effect would thus depend on a variety of factors, such as the relative rate of formation and degradation of the intermediate oxirane, on its stability with respect to spontaneous isomerization to the corresponding phenol and on its chemical electrophilic reactivity.2. Epoxide hydrases, which convert such intermediate oxiranes t...

Structure, function and regulation of P-glycoprotein and its clinical relevance in drug disposition

Abstract: 1. P-glycoprotein (P-gp/MDR1), one of the most clinically important transmembrane transporters in humans, is encoded by the ABCB1/MDR1 gene. Recent insights into the structural features of P-gp/MDR...

Antioxidant and pro-oxidant properties of active rosemary constituents: carnosol and carnosic acid

Abstract: 1. Carnosol and carnosic acid have been suggested to account for over 90% of the antioxidant properties of rosemary extract.2. Purified carnosol and carnosic acid are powerful inhibitors of lipid peroxidation in microsomal and liposomal systems, more effective than propyl gallate.3. Carnosol and carnosic acid are good scavengers of peroxyl radicals (CCl3O2) generated by pulse radiolysis, with calculated rate constants of 1–3 × 106M-1 S-1 and 2.7 × 107M-1 S-1 respectively.4. Carnosic acid reacted with HOCl in such a way as to protect the protein α1-antiproteinase against inactivation.5. Both carnosol and carnosic acid stimulated DNA damage in the bleomycin assay but they scavenged hydroxyl radicals in the deoxyribose assay. The calculated rate constants for reaction with ·OH in the deoxyribose system for carnosol and carnosic acid were 8.7 × 1010M-1 and 5.9 × 1010M-1 S-1 respectively.6. Carnosic acid appears to scavenge H2O2, but it could also act as a substrate for the peroxidase system.7. Carnosic acid a...

Interaction of a series of nitriles with the alcohol-inducible isoform of P450: Computer analysis of structure—activity relationships

Abstract: 1. Structural studies are reported on a series of 20 nitriles of varying rates of P4502E-mediated oxidative metabolism.2. Parameters of molecular and electronic structure have been calculated for the generation of quantitative structure—activity relationships (QSARs) with the rates of oxidative metabolism of the nitriles, and with their acute toxicity.3. Correlations between molecular polarizability, excitation energy and biological activity are presented as a result of QSAR analysis.