# US 2014/0193847 A1 · Glutathione alkylester isotopologue and method for detecting reactive metabolite > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0193847 A1 - Document ID: US20140193847A1 - Status: Published application - Kind: A1 - Application number: 14/117,169 - Filed: 2012-05-21 - Published: 2014-07-10 - Earliest claimed: 2011-05-20 - Assignees: Kyorin Pharmaceutical Co., Ltd. - Inventors: Toshikazu Yamaoka - Web page: https://patentgrep.com/patent/US20140193847A1 ## CPC - G01N 33/4833: {of solid biological material, e.g. tissue samples, cell cultures (tissue in vivo A61B5/00; cell suspensions G01N33/48735)} - C07B 59/00: Introduction of isotopes of elements into organic compounds {; Labelled organic compounds per se} - C07K 5/0215: {containing natural amino acids, forming a peptide bond via their side chain functional group, e.g. epsilon-Lys, gamma-Glu} - G01N 33/94: involving narcotics {or drugs or pharmaceuticals, neurotransmitters or associated receptors} - H01J 49/0027: {Methods for using particle spectrometers} - G01N 2458/15: Non-radioactive isotope labels, e.g. for detection by mass spectrometry - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) - C07B: GENERAL METHODS OF ORGANIC CHEMISTRY; APPARATUS THEREFOR (preparation of carboxylic acid esters by telomerisation C07C67/47; telomerisation C08F) - C07K: PEPTIDES (peptides in foodstuffs A23; obtaining protein compositions for foodstuffs, working-up proteins for foodstuffs A23J; preparations for medicinal purposes A61K; peptides containing beta-lactam rings C07D; cyclic dipeptides not having in their molecule any other peptide link than those which form their ring, e.g. piperazine-2,5-diones, C07D; ergot alkaloids of the cyclic peptide type C07D519/02; macromolecular compounds having statistically distributed amino acid units in their molecules, i.e. when the preparation does not provide for a specific; but for a random sequence of the amino acid units, homopolyamides and block copolyamides derived from amino acids C08G69/00; macromolecular products derived from proteins C08H1/00; preparation of glue or gelatine C09H; single cell proteins, enzymes C12N; genetic engineering processes for obtaining peptides C12N15/00; compositions for measuring or testing processes involving enzymes C12Q; investigation or analysis of biological material G01N33/00) - H01J: ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS (spark-gaps H01T; electric arc lamps H05B31/00; particle accelerators H05H) ## Abstract [Problem] To provide a novel isotope-labeled compound that can be used as a trapping agent and that is useful for picking out drug-candidate compounds that produce reactive metabolites. [Solution] Provided is a glutathione alkylester isotopologue represented by general formula (1). In formula (1), R1 represents a linear or branched alkoxy group in which at least one of carbon, oxygen, and hydrogen atoms contained therein is isotope-labeled and which has 1 to 8 carbon atoms or a cycloalkoxy group in which at least one of carbon, oxygen, and hydrogen atoms contained therein is isotope-labeled and which has 3 to 8 carbon atoms. ## Claims ### Claim 1 A glutathione alkyl ester isotopologue represented by general formula (1). In the formula (1), R1 represents a linear or branched alkoxy group in which at least one of carbon, oxygen, and hydrogen atoms contained therein is isotope-labeled and which has 1 to 8 carbon atoms or a cycloalkoxy group in which at least one of carbon, oxygen, and hydrogen atoms contained therein is isotope-labeled and which has 3 to 8 carbon atoms. ### Claim 2 (depends on 1) The glutathione alkyl ester isotopologue according to claim 1, wherein the glutathione alkyl ester isotopologue is represented by general formula (2), and at least one of carbon, oxygen, and hydrogen atoms marked with an asterisk is isotope-labeled. ### Claim 3 (depends on 1) The glutathione alkyl ester isotopologue according to claim 1, wherein the glutathione alkyl ester isotopologue is represented by general formula (3). In the formula (3), D represents deuterium (2H). ### Claim 4 (depends on 1) A method for detecting a reactive metabolite comprising using the glutathione alkyl ester isotopologue according to claim 1. ### Claim 5 (depends on 4) The method for detecting a reactive metabolite according to claim 4, comprising: incubating a reaction sample containing the glutathione alkyl ester isotopologue, an auxiliary detection compound which is a compound obtained by substituting at least one atom contained in the glutathione alkyl ester isotopologue with an atom having a mass number different from a mass number of the at least one atom, and a drug candidate compound in the presence of a drug metabolic enzyme to thereby form a product containing a glutathione alkyl ester isotopologue-reactive metabolite adduct and an auxiliary detection compound-reactive metabolite adduct; and detecting a mass peak of the formed glutathione alkyl ester isotopologue-reactive metabolite adduct and a mass peak of the formed auxiliary detection compound-reactive metabolite adduct through analysis using a liquid chromatography-mass spectrometer (LC-MS). ### Claim 6 (depends on 5) The method for detecting a reactive metabolite according to claim 5, wherein a molar ratio of the glutathione alkyl ester isotopologue to the auxiliary detection compound in the reaction sample is 2:1 to 1:2. ### Claim 7 (depends on 5) The method for detecting a reactive metabolite according to claim 5, the method further comprising: adding dithiothreitol, 2-mercaptoethanol, or tris(2-carboxyethyl)phosphine to the product obtained by incubation; and then performing the analysis using the liquid chromatography-mass spectrometer (LC-MS). ### Claim 8 (depends on 5) The method for detecting a reactive metabolite according to claim 5, wherein a neutral loss scan method or a full scan method is performed in the analysis using the liquid chromatography-mass spectrometer (LC-MS). ### Claim 9 (depends on 5) The method for detecting a reactive metabolite according to claim 5, wherein the auxiliary detection compound is a non-labeled compound of the glutathione alkyl ester isotopologue contained in the reaction sample. ### Claim 10 (depends on 1) A method for producing the glutathione alkyl ester isotopologue according to claim 1, comprising reacting glutathione with a deuterated alcohol. ### Claim 11 (depends on 10) The method for producing the glutathione alkyl ester isotopologue substitution product according to claim 10, wherein the deuterated alcohol is ethanol-d6. ### Claim 12 (depends on 2) A method for detecting a reactive metabolite comprising using the glutathione alkyl ester isotopologue according to claim 2. ### Claim 13 (depends on 3) A method for detecting a reactive metabolite comprising using the glutathione alkyl ester isotopologue according to claim 3. ### Claim 14 (depends on 12) The method for detecting a reactive metabolite according to claim 12, comprising: incubating a reaction sample containing the glutathione alkyl ester isotopologue, an auxiliary detection compound which is a compound obtained by substituting at least one atom contained in the glutathione alkyl ester isotopologue with an atom having a mass number different from a mass number of the at least one atom, and a drug candidate compound in the presence of a drug metabolic enzyme to thereby form a product containing a glutathione alkyl ester isotopologue-reactive metabolite adduct and an auxiliary detection compound-reactive metabolite adduct; and detecting a mass peak of the formed glutathione alkyl ester isotopologue-reactive metabolite adduct and a mass peak of the formed auxiliary detection compound-reactive metabolite adduct through analysis using a liquid chromatography-mass spectrometer (LC-MS). ### Claim 15 (depends on 13) The method for detecting a reactive metabolite according to claim 13, comprising: incubating a reaction sample containing the glutathione alkyl ester isotopologue, an auxiliary detection compound which is a compound obtained by substituting at least one atom contained in the glutathione alkyl ester isotopologue with an atom having a mass number different from a mass number of the at least one atom, and a drug candidate compound in the presence of a drug metabolic enzyme to thereby form a product containing a glutathione alkyl ester isotopologue-reactive metabolite adduct and an auxiliary detection compound-reactive metabolite adduct; and detecting a mass peak of the formed glutathione alkyl ester isotopologue-reactive metabolite adduct and a mass peak of the formed auxiliary detection compound-reactive metabolite adduct through analysis using a liquid chromatography-mass spectrometer (LC-MS). ### Claim 16 (depends on 14) The method for detecting a reactive metabolite according to claim 14, wherein a molar ratio of the glutathione alkyl ester isotopologue to the auxiliary detection compound in the reaction sample is 2:1 to 1:2. ### Claim 17 (depends on 15) The method for detecting a reactive metabolite according to claim 15, wherein a molar ratio of the glutathione alkyl ester isotopologue to the auxiliary detection compound in the reaction sample is 2:1 to 1:2. ### Claim 18 (depends on 14) The method for detecting a reactive metabolite according to claim 14, wherein the auxiliary detection compound is a non-labeled compound of the glutathione alkyl ester isotopologue contained in the reaction sample. ### Claim 19 (depends on 15) The method for detecting a reactive metabolite according to claim 15, wherein the auxiliary detection compound is a non-labeled compound of the glutathione alkyl ester isotopologue contained in the reaction sample.