title: Rapid detection and characterization of minor reactive metabolites using stable-isotope trapping in combination with tandem mass spectrometry.
abstract: Stable-isotope trapping combined with mass spectrometry (MS) neutral loss scanning has recently been developed as a high-throughput method for the in vitro screening of major reactive metabolites. In fact, detection and identification of minor reactive metabolites are equally important since the minor metabolites, even though at low levels, may be highly reactive and also play an important role in drug-induced adverse reactions. In this study, 2-acetylthiophene, clozapine, troglitazone and 7-methylindole were selected as model compounds to further validate the advantages of this method for rapid detection and structural characterization of minor glutathione (GSH) adducts derived from reactive metabolites. The utility of the current method was clearly demonstrated by successful identification of novel reactive metabolites at low levels and also minor ones either masked by non-specific responses or co-eluted with other conjugates. In comparison with existing methods, this method is sensitive, efficient, and suitable for rapid screening and more complete profiling of reactive metabolites.
authors.affiliation: Division of Drug Discovery, Johnson & Johnson Pharmaceutical Research & Development, LLC, Spring House, PA 19477, USA. zyan@prdus.jnj.com
authors.forename: Zhengyin
authors.initials: Z
authors.lastname: Yan
authors.forename: Noureddine
authors.initials: N
authors.lastname: Maher
authors.forename: Rhoda
authors.initials: R
authors.lastname: Torres
authors.forename: Gary W
authors.initials: GW
authors.lastname: Caldwell
authors.forename: Norman
authors.initials: N
authors.lastname: Huebert
mesh_terms: D002839:Chromans / Q000378:metabolism; D003024:Clozapine / Q000378:metabolism; D005978:Glutathione / Q000737:chemistry; D006801:Humans; D007211:Indoles / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism*; D007553:Isotope Labeling; D007554:Isotopes; D013058:Mass Spectrometry / Q000379:methods*; D008862:Microsomes, Liver / Q000378:metabolism; D015394:Molecular Structure; D009281:Naphthalenes / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism*; D004364:Pharmaceutical Preparations / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism*; D012680:Sensitivity and Specificity; D013329:Structure-Activity Relationship; D013844:Thiazoles / Q000378:metabolism; D045162:Thiazolidinediones / Q000378:metabolism; D013997:Time Factors; D000077288:Troglitazone
chemical_list: D002839:Chromans; D007211:Indoles; D007554:Isotopes; D009281:Naphthalenes; D004364:Pharmaceutical Preparations; D013844:Thiazoles; D045162:Thiazolidinediones; C503376:2-acetylnaphthalene; C508418:7-methylindole; C041430:2-acetylthiophene-2-thiazolylhydrazone; D005978:Glutathione; D000077288:Troglitazone; D003024:Clozapine