title: Development and validation of a ultra performance LC-ESI/MS method for analysis of metabolic phenotypes of healthy men in day and night urine samples.
abstract: Ultra-performance LC coupled to quadrupole TOF/MS (UPLC-QTOF/MS) in positive and negative ESI was developed and validated to analyze metabolite profiles for urine from healthy men during the day and at night. Data analysis using principal components analysis (PCA) revealed differences between metabolic phenotypes of urine in healthy men during the day and at night. Positive ions with mass-to-charge ratio (m/z) 310.24 (5.35 min), 286.24 (4.74 min) and 310.24 (5.63 min) were elevated in the urine from healthy men at night compared to that during the day. Negative ions elevated in day urine samples of healthy men included m/z 167.02 (0.66 min), 263.12 (2.55 min) and 191.03 (0.73 min), whilst ions m/z 212.01 (4.77 min) were at a lower concentration in urine of healthy men during the day compared to that at night. The ions m/z 212.01 (4.77 min), 191.03 (0.73 min) and 310.24 (5.35 min) preliminarily correspond to indoxyl sulfate, citric acid and N-acetylneuraminic acid, providing further support for an involvement of phenotypic difference in urine of healthy men in day and night samples, which may be associated with notably different activities of gut microbiota, velocity of tricarboxylic acid cycle and activity of sialic acid biosynthesis in healthy men as regulated by circadian rhythm of the mammalian bioclock.
authors.affiliation: Department of Pharmacognosy, Heilongjiang University of Chinese Medicine, Harbin, China. wxj@hljucm.net
authors.forename: Xijun
authors.initials: X
authors.lastname: Wang
authors.forename: Haitao
authors.initials: H
authors.lastname: Lv
authors.forename: Guangmei
authors.initials: G
authors.lastname: Zhang
authors.forename: Wenjun
authors.initials: W
authors.lastname: Sun
authors.forename: Dixin
authors.initials: D
authors.lastname: Zhou
authors.forename: Guozheng
authors.initials: G
authors.lastname: Jiao
authors.forename: Yang
authors.initials: Y
authors.lastname: Yu
mesh_terms: D000328:Adult; D002853:Chromatography, Liquid / Q000295:instrumentation / Q000379:methods; D002940:Circadian Rhythm; D019343:Citric Acid / Q000378:metabolism / Q000652:urine*; D002952:Citric Acid Cycle; D006801:Humans; D007200:Indican / Q000378:metabolism / Q000652:urine*; D008297:Male; D019158:N-Acetylneuraminic Acid / Q000378:metabolism / Q000652:urine*; D010641:Phenotype; D012016:Reference Values; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D021241:Spectrometry, Mass, Electrospray Ionization / Q000295:instrumentation / Q000379:methods
chemical_list: D019343:Citric Acid; D019158:N-Acetylneuraminic Acid; D007200:Indican