BACKGROUND Ginsenosides such as Rb1, Rg3 and Rh2 are major bioactive components of Panax ginseng. This in vivo study investigates the metabolic pathways of ginsenosides Rb1, Rg3 and Rh2 orally administered to rats. METHODS High performance liquid chromatography-mass spectrometry (LC-MS) and tandem mass spectrometry (MS-MS) techniques, particularly liquid chromatography electrospray ionization...

BACKGROUND The tobacco-specific nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) and its reduction product in the body, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL), are potent pulmonary carcinogens. We have measured total NNAL in the U.S. population of tobacco users and nonsmokers exposed to secondhand smoke. METHODS We measured total urinary NNAL (free NNAL plus its ...

In forensic analysis of explosives, analytical methods are required that combine good separation characteristics with highly specific and sensitive detection. Two novel techniques, liquid chromatography/mass spectrometry (LC/MS) and tandem mass spectrometry (MS/MS) have such specifications. These are now well-established analytical techniques for separation and identification of mixtures and fo...

Traditional analysis of liquid chromatography-mass spectrometry (LC-MS) data, typically performed by reviewing chromatograms and the corresponding mass spectra, is both time-consuming and difficult. Detailed data analysis is therefore often omitted in proteomics applications. When analysing multiple proteomics samples, it is usually only the final list of identified proteins that is reviewed. T...

A method using liquid chromatography/tandem mass spectrometry (LC/MS/MS) was developed for the determination of 17alpha-ethynylestradiol in fish liver; a second method using LC/MS was developed for the determination of carbamazepine, diazepam, simvastatin, and oxybenzone in fish liver. The fish liver samples were extracted and cleaned up by using liquid-liquid extraction and solid-phase extract...

The reversible phosphorylation of proteins is a dynamic process that plays a major role in many vital physiological processes by transmitting signals within cellular pathways and networks. Proteomic measurements using mass spectrometry are capable of characterizing the sites of protein phosphorylation and to quantify their change in abundance. However, the low stoichiometry of protein phosphory...

This is a review of analytical methods, such as spectrophotometry, derivative spectrophotometry and various chromatographic (gas chromatography-GC, high-performance liquid chromatography-HPLC, thin-layer chromatography-TLC, high-performance thin-layer chromatography-HPTLC, liquid chromatography-tandem mass spectrometry-LC-MS, microchip electrophoresis-MCE, capillary electrophoresis-CE) and elec...

This open-label, single-period study in healthy subjects estimated evacetrapib absolute bioavailability following simultaneous administration of a 130-mg evacetrapib oral dose and 4-h intravenous (IV) infusion of 175 µg [(13) C8 ]-evacetrapib as a tracer. Plasma samples collected through 168 h were analyzed for evacetrapib and [(13) C8 ]-evacetrapib using high-performance liquid chromatography/...

BACKGROUND Lenvatinib is an oral, multitargeted, tyrosine kinase inhibitor under clinical investigation in solid tumors. In vitro evidence indicates that lenvatinib metabolism may be modulated by ketoconazole, an inhibitor of CYP3A4 and p-glycoprotein. METHODS In this Phase I, single-center, randomized, open-label, two-period, crossover study, healthy adults (18-55 years; N = 18) were randomi...

ownloade kground: The tobacco-specific nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) and uction product in the body, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL), are potent pulmoarcinogens. We have measured total NNAL in the U.S. population of tobacco users and nonsmokers d to secondhand smoke. thods: We measured total urinary NNAL (free NNAL plus its glucuronides fo...