High-performance liquid chromatography metabolite profile

Ni et al. [143] investigated the profile of the major metabolites of primaquine produced by in vitro liver microsomal metabolism, with silica gel thin-layer and high performance liquid chromatography analysis. Results indicated that the liver microsomal metabolism could simultaneously produce both 5-hydroxyprimaquine (quinoline ring oxidation product) and carboxyprimaquine (side-chain oxidative deamination product). However, the quantitative comparative study of microsomal metabolism showed that the production of 5-hydroxyprimaquine was far much higher than that of carboxyprimaquine. 

Ni et al. [144] also investigated the profiles of major metabolites of primaquine produced from liver microsomal and mitochondrial metabolism, in vitro by silica gel thin-layer and reversed-phase high performance liquid chromatography. The results... 

Superior sensitivity, efficiency, and specificity have made high-performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS), the predominant analytical technique for characterization and quantitative analysis of metabolites (Kostiainen et al., 2003 Ma et al., 2006 Prakash et al., 2007). Ion trap, triple-quadrupole, and quadmpole time-of-flight (Q-TOF) mass spectrometers are routinely used to profile and characterize metabolites in plasma and excreta (Ma et al., 2006). The combination of scan types and features available on mass spectrometers of different design (product ion, MS", neutral loss, precursor ion scans, accurate mass measurements) allows identification and characterization of putative and unexpected metabolites with or without little prior knowledge of biotransformation pathways of a given dmg molecule. 

Nutritional and nutritional status markedly influence xenobiotic metabolism in laboratory animals. Microsomes were prepared from the livers of rats which had been fed chow or modified AIN-76 diets with or without oxidized or unoxidized sulfur amino acids for 7 days. The pattern of benzo(a)pyrene (BaP) metabolites formed by each microsomal preparation in the presence of a NADPH-generating system was determined using high performance liquid chromatography (HPLC). The results indicate that oxidized sulfur amino acids induce different forms of cytochromes P-450 in rat liver Which are reflected by different BaP metabolic profiles. 

The requirement of this study is to demonstrate that the toxicity test animal has been exposed to all of the major metabolites seen in the food animal. If a major food animal metabolite is not detected in the excreta of the test animal, residues in organs such as the liver and kidney of those animals are then profiled. If major metabolites from the food animal are still not found, then the sponsor must examine the metabolite profiles of the other laboratory species until all of the major food animal metabolites have been accounted for. If a majw metabolite from the food producing species is not detected in the test species, then separate feeding studies of the untest major metabolite must be undertaken unless its toxicity can be evaluated by some other means. Chromatographic techniques such as high performance liquid chromatography are often used for proHling metabolites. This type of metabolic evaluation is commonly found in the literature (6),... 

The first set of information generated from the ADME studies are the overall plasma profiles of total radioactivity (TRA) versus time which is compared to the plasma profile of parent versus time measured by a validated LC/MS/MS assay. For those drugs where the parent is the major component at all time points in plasma, the total radioactivity profile usually parallels the profile of the parent. Metabolie profiles of plasma samples generated at different time points by high-performance liquid chromatography (HPLC) analysis followed by radioactivity and mass spectrometric detection provide exposure-related information for parent and metabolites in humans and animal species. In addition, this profile provides information about metabolites that humans are exposed to and how this compares to exposures in animal species. 

Hosoda K, Furuta T, Yokokawa A, Ogura K, Hiratsuka A, Ishii K. Plasma profiling of intact isoflavone metabolites by high-performance liquid chromatography and mass spectrometric identification of flavone glycosides daidzin and genistin in human plasma after administration of kinako. Drug Metab Dispos 2008 36 1485-1495. 

The principal feature which distinguishes the metabolism of allopurinol in leishmania is the rapid formation of allopurinol ribonucleoside monophosphate (HPPR-MP). This can be demonstrated by grow hjL donovani in the presence of (6- C)-allopurinol and analyzing the perchloric acid-soluble extracts by high performance liquid chromatography (HPLC). It is the predominant radioactive material in the elution profile. The chromatogram reveals three other radio-labeled compounds. The first radioactive metabolite, which appears ahead of HPPR-MP, is 4-aminopyrazolopyrimidine ribonucleoside monophosphate (APPR-MP). The second is between ADP and GDP and the third between ATP and GTP. These are 4-aminopyrazolopyrimidine ribonucleoside diphosphate (APPR-DP) and triphosphate (APPR-TP), respectively. When the RNA from these cells is analyzed, 4-aminopyrazolopyrimidine (APP) can be found in the RNA. ... 

---