Integrated, nontargeted ultrahigh performance liquid chromatography/electrospray ionization tandem mass spectrometry platform for the identification and relative quantification of the small-molecule complement of biological systems.

To address the challenges associated with metabolomics analyses, such as identification of chemical structures and elimination of experimental artifacts, we developed a platform that integrated the chemical analysis, including identification and relative quantification, data reduction, and quality assurance components of the process. The analytical platform incorporated two separate ultrahigh performance liquid chromatography/tandem mass spectrometry (UHPLC/MS/MS(2)) injections; one injection was optimized for basic species, and the other was optimized for acidic species. This approach permitted the detection of 339 small molecules, a total instrument analysis time of 24 min (two injections at 12 min each), while maintaining a median process variability of 9%.

Analysis of the adult human plasma metabolome.

Objective: It is well established that disease states are associated with biochemical changes (e.g., diabetes/glucose, cardiovascular disease/cholesterol), as are responses to chemical agents (e.

High-throughput bioassay-guided fractionation: a technique for rapidly assigning observed activity to individual components of combinatorial libraries, screened in HTS bioassays.

In this paper, we describe an automated, high-throughput analytical tool for the unambiguous characterization of the active component(s) of a combinatorially derived reaction mixture. We call this technique high-throughput bioassay-guided fractionation (BGF). The novel aspects of this communication are the systematization of the BGF concept, the application of BGF to combinatorial chemistry, and the high-throughput nature of the identification technique.

Effect of testosterone suppression on the pharmacokinetics of a potent gnRH receptor antagonist.

Purpose: The expression of cytochrome P450 enzymes (CYPs) in animals and humans is under complex hormonal regulation. Chronic treatment with drugs that alter sex hormone levels such as GnRH receptor agonists or antagonists may affect the expression of hormone-dependent CYPs, and as a result the pharmacokinetics of drugs metabolized by them.

Methods: Enzyme kinetic parameters were obtained by incubating AG-045572 (0.