Oxidative metabolism of 5-o-caffeoylquinic acid (chlorogenic acid), a bioactive natural product, by metalloporphyrin and rat liver mitochondria.

Synthetic metalloporphyrins, in the presence of monooxygen donors, are known to mimic the various reactions of cytochrome P450 enzymes systems in the oxidation and oxygenation of various drugs and biologically active compounds. This paper reports an HPLC-MS-MS investigation of chlorogenic acid (CGA) oxidation by iodosylbenzene using iron(III) tetraphenylporphyrin chloride as catalyst. The oxidation products have been detected by sequential MS analyses.

Enantioselective analysis of primaquine and its metabolite carboxyprimaquine by capillary electrophoresis.

An enantioselective capillary electrophoresis method for the simultaneous determination of primaquine (PQ) and carboxyprimaquine (CPQ) in rat liver mitochondrial fraction, suitable for in vitro metabolism studies is presented. The drug and metabolite were extracted by liquid-liquid extraction using ethyl ether. The enantiomers were resolved in a fused-silica capillary, 50 microm inside diameter (ID) and 24 cm of effective length, using an electrolyte solution consisting of a 20 mmol/L sodium phosphate solution, pH 3.

Enantioselective analysis of disopyramide and mono-N-dealkyldisopyramide in plasma and urine by high-performance liquid chromatography on an amylose-derived chiral stationary phase.

An enantioselective high-performance liquid chromatography method was developed for the simultaneous determination of disopyramide (DP) and mono-N-dealkyldisopyramide (MND) enantiomers in plasma and urine. The drugs were extracted from plasma samples by liquid-liquid extraction with dichloromethane after protein precipitation with trichloroacetic acid; the urine samples were processed by liquid-liquid extraction with dichloromethane. The enantiomers were resolved on a Chiralpak AD column using hexane-ethanol (91:9, v/v) plus 0.