title: Reversed-phase high-performance liquid chromatographic approach to determine total lymphocyte concentrations of 6-thioguanine, methylmercaptopurine and methylthioguanine in humans.
abstract: A reversed-phase high-performance liquid chromatographic (HPLC) procedure was developed to quantify intracellular lymphocyte 6-thioguanine, methylmercaptopurine and methylthioguanine. The free base of each metabolite was obtained by acid hydrolysis, which allowed for a total determination of thiopurine metabolites. 6-Thioguanine was analyzed on an octadecylsilane column using acetonitrile-10 mM sodium phosphate (11:89), pH 7, containing 0.06% tetrabutylammonium chloride. 6-Thioguanine was oxidized with potassium permanganate, and fluorescence was measured at 330 nm excitation and 410 nm emission. Methylmercaptopurine and methylthioguanine were separated on a cyanopropylsilane column using methanol-40 mM sodium phosphate (22:78), pH 2.7, and detected by ultraviolet absorbance at 314 and 290 nm, respectively.
authors.affiliation: Department of Pharmacy Practice, College of Pharmacy, University of Minnesota, Minneapolis 55455.
authors.forename: G R
authors.initials: GR
authors.lastname: Erdmann
authors.forename: J C
authors.initials: JC
authors.lastname: Steury
authors.forename: B C
authors.initials: BC
authors.lastname: Carleton
authors.forename: R J
authors.initials: RJ
authors.lastname: Stafford
authors.forename: B C
authors.initials: BC
authors.lastname: Bostrom
authors.forename: D M
authors.initials: DM
authors.lastname: Canafax
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D005453:Fluorescence; D006801:Humans; D008214:Lymphocytes / Q000737:chemistry*; D015122:Mercaptopurine / Q000031:analogs & derivatives* / Q000097:blood; D013866:Thioguanine / Q000031:analogs & derivatives* / Q000097:blood*
chemical_list: C035366:6-methylthioguanine; C010240:6-methylthiopurine; D015122:Mercaptopurine; D013866:Thioguanine