Mass spectrometry plays a key role in drug metabolite identification, an integral part of drug discovery and development. The development of high-resolution (HR) MS instrumentation with improved accuracy and stability, along with new data processing techniques, has improved the quality and productivity of metabolite identification processes. In this minireview, HR-MS-based targeted and non-targ...

a chemiluminescence (cl) method has been developed for the determination of hydroxyzine (hyd) and its metabolite cetirizine (cet). the method is based on sensitizing effect of cet and hyd on the weak cl reaction between ru(phen)32+ and acidic ce(iv). a mechanism for the cl reaction has been proposed on the basis of uv-vis, fluorescent and cl spectra. by using the recommended procedure, the cali...

Living organisms produce metabolites of many types via metabolic reactions. Especially, flavonoids, a type of secondary metabolite, of plant species are interesting examples. Since plant species are believed to have specific flavonoids that were formed response to diverse environments, elucidation of the design principles of metabolite distributions across plant species is important for underst...

Clopidogrel (SR25990C, PLAVIX) is a potent antiplatelet drug, which has been recently launched and is indicated for the prevention of vascular thrombotic events in patients at risk. Clopidogrel is inactive in vitro, and a hepatic biotransformation is necessary to express the full antiaggregating activity of the drug. Moreover, 2-oxo-clopidogrel has been previously suggested to be the essential ...

Robust spectral analysis of magnetic resonance spectroscopy data frequently uses a spectral model with prior metabolite signal information within a nonlinear least squares optimization algorithm. Starting values for the spectral model greatly influence the final results. Short echo time magnetic resonance spectroscopy contains broad signals that overlap with metabolite signals, complicating the...

A colorimetric method for detection and assay of mustard gas in urine after addition of thymolphthalein is reported. The detection limit was 80 ng/ml of llrine. Mustard gas could also be detected in urine after extraction with gas chromatography using FID detector. The detection limit was 10 ng/ml. In addition, thiodiglycol, a metabolite of mustard gas, could be converted to mustard with ...

We describe a simple, reproducible liquid-chromatographic method for determination of esmolol (a short-acting beta blocker) and its major metabolite in human urine. Esmolol is extracted from urine at a pH of 8.4 into methylene chloride; the more polar metabolite remains in the aqueous phase. We then measure esmolol with a muBondapak C18 column and measure ultraviolet absorbance at 229 nm; the m...

K E Y W O R D S Convergence chromatography, UPC, tandem quadrupole MS, triple quadrupole MS, liquid-liquid extraction, LLE, clopidogrel A P P L I C AT IO N B E N E F I T S Direct injection of bioanalytical liquid-liquid extracts (LLE) onto UPC2®/MS instrumentation without the need for evaporation and reconstitution. IN T RO DU C T IO N Clopidogrel, shown in Figure 1, is a thienopyridine derivat...

Recent analyses demonstrated that metabolites are unlikely to contribute significantly to clinical inhibition of cytochrome P450 (P450)-mediated drug metabolism, and that only ∼2% of this type of drug interaction could not be predicted from the parent drug alone. Due to generally increased polarity and decreased permeability, metabolites are less likely to interact with P450s, but their disposi...