Isotope Enhanced Approaches in Metabolomics

  • G. A. Nagana GowdaEmail author
  • Narasimhamurthy Shanaiah
  • Daniel Raftery
Part of the Advances in Experimental Medicine and Biology book series (AEMB, volume 992)


The rapidly growing area of “metabolomics,” in which a large number of metabolites from body fluids, cells or tissue are detected quantitatively, in a single step, promises immense potential for a number of disciplines including early disease diagnosis, therapy monitoring, systems biology, drug discovery and nutritional science. Because of its ability to detect a large number of metabolites in intact biological samples reproducibly and quantitatively, nuclear magnetic resonance (NMR) spectroscopy has emerged as one of the most powerful analytical techniques in metabolomics. NMR spectroscopy of biological samples with isotope labeling of metabolites using nuclei such as 2H, 13C, 15N and 31P, either in vivo or ex vivo, has dramatically improved our ability to identify low concentrated metabolites and trace important metabolic pathways. Considering the somewhat limited sensitivity and high complexity of NMR spectra of biological samples, efforts have been made to increase sensitivity and selectivity through isotope labeling methods, which pave novel avenues to unravel biological complexity and understand cellular functions in health and various disease conditions. This chapter describes current developments in isotope labeling of metabolites in vivo as well as ex vivo, and their potential metabolomics applications.


Nuclear Magnetic Resonance Nuclear Magnetic Resonance Spectrum Nuclear Magnetic Resonance Spectroscopy Nuclear Magnetic Resonance Experiment Heteronuclear Single Quantum Coherence 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


  1. 1.
    Nicholson JK, Lindon JC, Holmes E (1999) ‘Metabonomics’: understanding the metabolic responses of living systems to pathophysiological stimuli via multivariate statistical analysis of biological NMR spectroscopic data. Xenobiotica 29:1181–1189PubMedGoogle Scholar
  2. 2.
    Fiehn O (2002) Metabolomics-the link between genotype and phenotype. Plant Mol Biol 48:155–171PubMedGoogle Scholar
  3. 3.
    Saghatelian A, Cravatt BF (2005) Global strategies to integrate the proteome and metabolome. Curr Opin Chem Biol 9:62–68PubMedGoogle Scholar
  4. 4.
    Assfalg M, Bertini I, Colangiuli D et al (2008) Evidence of different metabolic phenotypes in humans. Proc Natl Acad Sci USA 105:1420–1424PubMedGoogle Scholar
  5. 5.
    Nicholson JK, Lindon JC (2008) Systems biology: metabonomics. Nature 455:1054–1056PubMedGoogle Scholar
  6. 6.
    van der Greef J, Smilde AK (2005) Symbiosis of chemometrics and metabolomics: past, present, and future. J Chemom 19:376–386Google Scholar
  7. 7.
    Nagana Gowda GA, Zhang S, Gu H et al (2008) Metabolomics based methods for early disease diagnostics: a review. Exp Rev Mol Diagn 8:627–633Google Scholar
  8. 8.
    NaganaGowda GA, Ijare OB, Shanaiah N et al (2009) Combining NMR spectroscopy and mass spectrometry in biomarker discovery. Biomark Med 3:307–322Google Scholar
  9. 9.
    Holmes E, Wilson ID, Nicholson JK (2008) Metabolic phenotyping in health and disease. Cell 134:714–717PubMedGoogle Scholar
  10. 10.
    Weljie AM, Newton J, Mercier P et al (2006) Targeted profiling: quantitative analysis of 1H NMR metabolomics data. Anal Chem 78:4430–4442PubMedGoogle Scholar
  11. 11.
    Lewis IA, Schommer SC, Hodis B et al (2007) Method for determining molar concentrations of metabolites in complex solutions from two-dimensional 1H-13C NMR spectra. Anal Chem 79:9385–9390PubMedGoogle Scholar
  12. 12.
    Robinette SL, Zhang F, Brüschweiler-Li L et al (2008) Web server based complex mixture analysis by NMR. Anal Chem 80:3606–3611PubMedGoogle Scholar
  13. 13.
    Chikayama E, Sekiyama Y, Okamoto M et al (2010) Statistical indices for simultaneous large-scale metabolite detections for a single NMR spectrum. Anal Chem 82:1653–1658PubMedGoogle Scholar
  14. 14.
    Keun HC (2006) Metabonomic modeling of drug toxicity. Pharmacol Ther 109:92–106PubMedGoogle Scholar
  15. 15.
    Coen M, Holmes E, Lindon JC et al (2008) NMR-based metabolic profiling and metabonomic approaches to problems in molecular toxicology. Chem Res Toxicol 2:9–27Google Scholar
  16. 16.
    Bollard ME, Stanley EG, Lindon JC et al (2005) NMR-based metabonomic approaches for evaluating physiological influences on biofluid composition. NMR Biomed 18:143–162PubMedGoogle Scholar
  17. 17.
    Nagana Gowda GA, Ijare OB, Somashekar BS et al (2006) Single-step analysis of individual conjugated bile acids in human bile using 1H NMR spectroscopy. Lipids 41:591–603Google Scholar
  18. 18.
    Nagana Gowda GA (2010) Human bile as a rich source of biomarkers for hepatopancreatobiliary cancers. Biomark Med 4:299–314Google Scholar
  19. 19.
    Nagana Gowda GA (2011) NMR spectroscopy for discovery and quantitation of biomarkers of disease in human bile. Bioanalysis 3:1877–1890Google Scholar
  20. 20.
    Bala L, Ghoshal UC, Ghoshal U et al (2006) Malabsorption syndrome with and without small intestinal bacterial overgrowth: a study on upper-gut aspirate using 1H NMR spectroscopy. Magn Reson Med 56:738–744PubMedGoogle Scholar
  21. 21.
    Griffin JL, Kauppinen RA (2007) Tumour metabolomics in animal models of human cancer. J Proteome Res 6:498–505PubMedGoogle Scholar
  22. 22.
    Villas-Boas SG, Hojer-Pedersen J, Akesson M et al (2005) Global metabolite analysis of yeast: evaluation of sample preparation methods. Yeast 22:1155–1169PubMedGoogle Scholar
  23. 23.
    Bollard ME, Xu JS, Purcell W et al (2002) Metabolic profiling of the effects of D-galactosamine in liver spheroids using 1H NMR and MAS-NMR spectroscopy. Chem Res Toxicol 15:1351–1359PubMedGoogle Scholar
  24. 24.
    Boroujerdi AF, Vizcaino MI, Meyers A et al (2009) NMR-based microbial metabolomics and the temperature-dependent coral pathogen Vibrio coralliilyticus. Environ Sci Technol 43:7658–7664PubMedGoogle Scholar
  25. 25.
    Lyng H, Sitter B, Bathen TF et al (2007) Metabolic mapping by use of high-resolution magic angle spinning 1H MR spectroscopy for assessment of apoptosis in cervical carcinomas. BMC Cancer 7:11PubMedGoogle Scholar
  26. 26.
    Sitter B, Bathen T, Hagen B et al (2004) Cervical cancer tissue characterized by high-resolution magic angle spinning MR spectroscopy. Magn Reson Mater Phys Biol Med 16:174–181Google Scholar
  27. 27.
    Schenetti L, Mucci A, Parenti F et al (2006) HR-MAS NMR spectroscopy in the characterization of human tissues: application to healthy gastric mucosa. Concepts Magn Reson A 28A:430–443Google Scholar
  28. 28.
    Beckonert O, Keun HC, Ebbels TMD et al (2007) Metabolic profiling, metabolomic and metabonomic procedures for NMR spectroscopy of urine, plasma, serum and tissue extracts. Nat Protoc 2:2692–2703PubMedGoogle Scholar
  29. 29.
    Beckonert O, Coen M, Keun HC et al (2010) High-resolution magic-angle-spinning NMR spectroscopy for metabolic profiling of intact tissues. Nat Protoc 5:1019–1032PubMedGoogle Scholar
  30. 30.
    Nicholson JK, Foxall PJD, Spraul M et al (1995) 750 MHz 1H and 1H-13C NMR spectroscopy of human blood-plasma. Anal Chem 67:793–811PubMedGoogle Scholar
  31. 31.
    Balayssac S, DelsucM-A GV et al (2009) Two-dimensional DOSY experiment with Excitation Sculpting water suppression for the analysis of natural and biological media. J Magn Reson 196:78–83PubMedGoogle Scholar
  32. 32.
    Van Lokeren L, Kerssebaum R, Willem R et al (2008) ERETIC implemented in diffusion-ordered NMR as a diffusion reference. Magn Reson Chem 46:S63–S71PubMedGoogle Scholar
  33. 33.
    Smith LM, Maher AD, Cloarec O et al (2007) Statistical correlation and projection methods for improved information recovery from diffusion-edited NMR spectra of biological samples. Anal Chem 79:5682–5689PubMedGoogle Scholar
  34. 34.
    Simpson AJ, Brown SA (2005) Purge NMR: effective and easy solvent suppression. J Magn Reson 175:340–346PubMedGoogle Scholar
  35. 35.
    Ogg RJ, Kingsley PB, Taylor JS (1994) Wet, a T-1-insensitive and B-1-insensitive water-suppression method for in-vivo localized 1H NMR spectroscopy. J Magn Reson B 104:1–10PubMedGoogle Scholar
  36. 36.
    Mo H, Raftery D (2008) Improved residual water suppression: WET180. J Biomol NMR 41:105–111PubMedGoogle Scholar
  37. 37.
    Hoult DI (1976) Solvent peak saturation with single-phase and quadrature fourier transformation. J Magn Reson 21:337–347Google Scholar
  38. 38.
    Sandusky P, Raftery D (2005) Use of selective TOCSY NMR experiments for quantifying minor components in complex mixtures: application to the metabonomics of amino acids in honey. Anal Chem 77:2455–2463PubMedGoogle Scholar
  39. 39.
    Sandusky P, Raftery D (2005) Use of semiselective TOCSY and the pearson correlation for the metabonomic analysis of biofluid mixtures: application to urine. Anal Chem 77:7717–7723PubMedGoogle Scholar
  40. 40.
    Sandusky P, Appiah-Amponsah E, Raftery D (2011) Use of optimized 1D TOCSY NMR for improved quantitation and metabolomic analysis of biofluids. J Biomol NMR 49:281–290PubMedGoogle Scholar
  41. 41.
    Dumas ME, Canlet C, André F et al (2002) Metabonomic assessment of physiological disruptions using 1H-13C HMBC-NMR spectroscopy combined with pattern recognition procedures performed on filtered variables. Anal Chem 74:2261–2273PubMedGoogle Scholar
  42. 42.
    Tang HR, Wang Y, Nicholson JK et al (2004) Use of relaxation-edited one-dimensional and two dimensional nuclear magnetic resonance spectroscopy to improve detection of small metabolites in blood plasma. Anal Biochem 325:260–272PubMedGoogle Scholar
  43. 43.
    Xi Y, de Ropp JS, Viant MR et al (2006) Automated screening for metabolites in complex mixtures using 2D COSY NMR spectroscopy. Metabolomics 2:221–233Google Scholar
  44. 44.
    Chikayama E, Suto M, Nishihara T et al (2008) Systematic NMR analysis of stable isotope labeled metabolite mixtures in plant and animal systems: coarse grained views of metabolic pathways. PLoS One 3:e3805PubMedGoogle Scholar
  45. 45.
    Fan TWM, Bandura LL, Higashi RM et al (2005) Metabolomics-edited transcriptomics analysis of Se anticancer action in human lung cancer cells. Metabolomics 1:325–339Google Scholar
  46. 46.
    Ludwig C, Viant MR (2010) Two-dimensional J-resolved NMR spectroscopy: review of a key methodology in the metabolomics toolbox. Phytochem Anal 21:22–32PubMedGoogle Scholar
  47. 47.
    Parsons HM, Ludwig C, Gunther UL et al (2007) Improved classification accuracy in 1-and 2-dimensional NMR metabolomics data using the variance stabilising generalised logarithm transformation. BMC Bioinform 8:234Google Scholar
  48. 48.
    Hyberts SG, Heffron GJ, Tarragona NG et al (2007) Ultrahigh-resolution 1H-13C HSQC spectra of metabolite mixtures using nonlinear sampling and forward maximum entropy reconstruction. J Am Chem Soc 129:5108–5116PubMedGoogle Scholar
  49. 49.
    Viant MR (2003) Improved methods for the acquisition and interpretation of NMR metabolomic data. Biochem Biophys Res Commun 310:943–948PubMedGoogle Scholar
  50. 50.
    Lindon JC, Holmes E, Nicholson JK (2006) Metabonomics techniques and applications to pharmaceutical research & development. Pharm Res 23:1075–1088PubMedGoogle Scholar
  51. 51.
    Kind T, Tolstikov V, Fiehn O et al (2007) A comprehensive urinary metabolomic approach for identifying kidney cancer. Anal Biochem 363:185–195PubMedGoogle Scholar
  52. 52.
    Wilson ID, Nicholson JK, Castro-Perez J et al (2005) High resolution “ultra performance” liquid chromatography coupled to a-TOF mass spectrometry as a tool for differential metabolic pathway profiling in functional genomic studies. J Proteome Res 4:591–598PubMedGoogle Scholar
  53. 53.
    Spraul M, Freund AS, Nast RE et al (2003) Advancing NMR sensitivity for LC-NMR-MS using a cryo-flow probe: application to the analysis of acetaminophen metabolites in urine. Anal Chem 75:1536–1541PubMedGoogle Scholar
  54. 54.
    Lacey ME, Subramanian R, Olson DL et al (1999) High-resolution NMR spectroscopy of sample volumes from 1 nL to 10 μL. Chem Rev 99:3133–3152PubMedGoogle Scholar
  55. 55.
    Olson DL, Peck TL, Webb AG et al (1995) High-resolution microcoil 1H-NMR for mass-limited, nanoliter-volume samples. Science 270:1967–1970Google Scholar
  56. 56.
    Webb AG (2005) Microcoil nuclear magnetic resonance spectroscopy. J Pharm Biomed Anal 38:892–903PubMedGoogle Scholar
  57. 57.
    Kc R, Henry ID, Park GHJ et al (2009) Design and construction of a versatile dual volume heteronuclear double resonance microcoil NMR probe. J Magn Reson 197:186–192PubMedGoogle Scholar
  58. 58.
    Henry D, Park GHJ, Kc R et al (2008) Design and construction of a microcoil NMR probe for the routine analysis of 20-mu L samples. Concepts Magn Reson B Magn Reson Eng 33B:1–8Google Scholar
  59. 59.
    Bergeron SJ, Henry ID, Santini RE et al (2008) Saturation transfer double-difference NMR spectroscopy using a dual solenoid microcoil difference probe. Magn Reson Chem 46:925–929PubMedGoogle Scholar
  60. 60.
    Kc R, Gowda YN, Djukovic D et al (2010) Susceptibility-matched plugs for microcoil NMR probes. J Magn Reson 205:63–68PubMedGoogle Scholar
  61. 61.
    Guo K, Bamforth F, Li L (2011) Qualitative metabolome analysis of human cerebrospinal fluid by 13C-/12C-isotope dansylation labeling combined with liquid chromatography fourier transform ion cyclotron resonance mass spectrometry. J Am Soc Mass Spectrom 22:339–347PubMedGoogle Scholar
  62. 62.
    Huang X, Regnier FE (2008) Differential metabolomics using stable isotope labeling and two-dimensional gas chromatography with time-of-flight mass spectrometry. Anal Chem 80:107–114PubMedGoogle Scholar
  63. 63.
    Yang WC, Adamec J, Regnier FE (2007) Enhancement of the LC/MS analysis of fatty acids through derivatization and stable isotope coding. Anal Chem 79:5150–5157PubMedGoogle Scholar
  64. 64.
    Yang WC, Regnier FE, Sliva D et al (2008) Stable isotope-coded quaternization for comparative quantification of estrogen metabolites by high-performance liquid chromatography-electrospray ionization mass spectrometry. J Chromatogr B Anal Technol Biomed Life Sci 870:233–240Google Scholar
  65. 65.
    Lane AN, Fan TWM, Bousamra M II et al (2011) Stable isotope-resolved metabolomics (SIRM) in cancer research with clinical application to nonsmall cell lung cancer. OMICS A J Integr Biol 15:173–182Google Scholar
  66. 66.
    Fan TW, Lane AN, Higashi RM et al (2011) Stable isotope resolved metabolomics of lung cancer in a SCID mouse model. Metabolomics 7:257–269PubMedGoogle Scholar
  67. 67.
    Fan TW, Lane AN, Higashi RM et al (2009) Altered regulation of metabolic pathways in human lung cancer discerned by (13)C stable isotope-resolved metabolomics (SIRM). Mol Cancer 8:41PubMedGoogle Scholar
  68. 68.
    Locasale JW, Grassian AR, Melman T et al (2011) Phosphoglycerate dehydrogenase diverts glycolytic flux and contributes to oncogenesis. Nat Genet 43:869–874PubMedGoogle Scholar
  69. 69.
    Fan TW, Lane AN (2011) NMR-based stable isotope resolved metabolomics in systems biochemistry. J Biomol NMR 49:267–280PubMedGoogle Scholar
  70. 70.
    Petch D, Butler M (1994) Profile of energy metabolism in a murine hybridoma: glucose and glutamine utilization. J Cell Physiol 161:71–76PubMedGoogle Scholar
  71. 71.
    Portais JC, Voisin P, Merle M et al (1996) Glucose and glutamine metabolism in C6 glioma cells studied by carbon-13 NMR. Biochimie 78:155–164PubMedGoogle Scholar
  72. 72.
    Mazurek S, Grimm H, Oehmke M et al (2000) Tumor M2-PK and glutaminolytic enzymes in the metabolic shift of tumor cells. Anticancer Res 20(6D):5151–5154PubMedGoogle Scholar
  73. 73.
    DeBerardinis RJ, Mancuso A, Daikhin E et al (2007) Beyond aerobic glycolysis: transformed cells can engage in glutamine metabolism that exceeds the requirement for protein and nucleotide synthesis. Proc Natl Acad Sci USA 104:19345–19350PubMedGoogle Scholar
  74. 74.
    Lane AN, Fan TW, Higashi RM et al (2009) Prospects for clinical cancer metabolomics using stable isotope tracers. Exp Mol Pathol 86:165–173PubMedGoogle Scholar
  75. 75.
    Lloyd SG, Zeng H, Wang P et al (2004) Lactate isotopomer analysis by 1H NMR spectroscopy: consideration of long-range nuclear spin-spin interactions. Magn Reson Med 51:1279–1282PubMedGoogle Scholar
  76. 76.
    Lane AN, Fan TW (2007) Quantification and identification of isotopomer distributions of metabolites in crude cell extracts using 1H TOCSY. Metabolomics 3:79–86Google Scholar
  77. 77.
    Burgess SC, Babcock EE, Jeffrey FM et al (2001) NMR indirect detection of glutamate to measure citric acid cycle flux in the isolated perfused mouse heart. FEBS Lett 505:163–167PubMedGoogle Scholar
  78. 78.
    Perdigoto R, Furtado AL, Porto A et al (2003) Sources of glucose production in cirrhosis by 2H2O ingestion and 2H NMR analysis of plasma glucose. Biochim Biophys Acta 1637:156–163PubMedGoogle Scholar
  79. 79.
    Kikuchi J, Shinozaki K, Hirayama T (2004) Stable isotope labeling of Arabidopsis thaliana for an NMR-based metabolomics approach. Plant Cell Physiol 45:1099–1104PubMedGoogle Scholar
  80. 80.
    Lane AN, Fan TW, Higashi RM (2008) Isotopomer based metabolic analysis by NMR and mass spectrometry. Biophys Tools Biol 84:541–588Google Scholar
  81. 81.
    Lane AN, Fan TW, Xie Z et al (2009) Isotopomer analysis of lipid biosynthesis by high resolution mass spectrometry and NMR. Anal Chim Acta 651:201–208PubMedGoogle Scholar
  82. 82.
    Coles NW, Johnstone RM (1962) Glutamine metabolism in Ehrlich ascites-carcinoma cells. Biochem J J83:284–291Google Scholar
  83. 83.
    Eagle H (1955) Nutrition needs of mammalian cells in tissue culture. Science 122:501–514PubMedGoogle Scholar
  84. 84.
    Wise DR, DeBerardinis RJ, Mancuso A et al (2008) Myc regulates a transcriptional program that stimulates mitochondrial glutaminolysis and leads to glutamine addiction. Proc Natl Acad Sci USA 105:18782–18787PubMedGoogle Scholar
  85. 85.
    Weis BC, Margolis D, Burgess SC et al (2004) Glucose production pathways by 2H and 13C NMR in patients with HIV-associated lipoatrophy. Magn Reson Med 51:649–654PubMedGoogle Scholar
  86. 86.
    Jones JG, Solomon MA, Cole SM et al (2001) An integrated (2)H and (13)C NMR study of gluconeogenesis and TCA cycle flux in humans. Am J Physiol Endocrinol Metab 281:E848–E856PubMedGoogle Scholar
  87. 87.
    Hausler N, Browning J, Merritt M et al (2006) Effects of insulin and cytosolic redox state on glucose production pathways in the isolated perfused mouse liver measured by integrated 2H and 13C NMR. Biochem J 394(Pt 2):465–473, Erratum in: Biochem J 2006; 395:663PubMedGoogle Scholar
  88. 88.
    Perdigoto R, Rodrigues TB, Furtado AL et al (2003) Integration of [U-13C]glucose and 2H2O for quantification of hepatic glucose production and gluconeogenesis. NMR Biomed 16:189–198PubMedGoogle Scholar
  89. 89.
    Jin ES, Jones JG, Merritt M et al (2004) Glucose production, gluconeogenesis, and hepatic tricarboxylic acid cycle fluxes measured by nuclear magnetic resonance analysis of a single glucose derivative. Anal Biochem 327:149–155PubMedGoogle Scholar
  90. 90.
    Burgess SC, Weis B, Jones JG et al (2003) Noninvasive evaluation of liver metabolism by 2H and 13C NMR isotopomer analysis of human urine. Anal Biochem 312:228–234PubMedGoogle Scholar
  91. 91.
    Merritt ME, Harrison C, Sherry AD et al (2011) Flux through hepatic pyruvate carboxylase and phosphoenolpyruvatecarboxykinase detected by hyperpolarized 13C magnetic resonance. Proc Natl Acad Sci USA 108:19084–19089PubMedGoogle Scholar
  92. 92.
    Schroeder MA, Atherton HJ, Ball DR et al (2009) Real-time assessment of Krebs cycle metabolism using hyperpolarized 13C magnetic resonance spectroscopy. FASEB J 23:2529–2538PubMedGoogle Scholar
  93. 93.
    Lewis IA, Karsten RH, Norton ME et al (2010) NMR method for measuring carbon-13 isotopic enrichment of metabolites in complex solutions. Anal Chem 82:4558–4563PubMedGoogle Scholar
  94. 94.
    Fernie AR, Trethewey RN, Krotzky AJ et al (2004) Metabolite profiling: from diagnostics to systems biology. Nat Rev Mol Cell Biol 5:763–769PubMedGoogle Scholar
  95. 95.
    Shanaiah N, Desilva A, Nagana Gowda GA et al (2007) Metabolite class selection of amino acids in biofluids using chemical derivatization and their enhanced 13C NMR. Proc Natl Acad Sci USA 104:11540–11544PubMedGoogle Scholar
  96. 96.
    Ye T, Mo H, Shanaiah N et al (2009) Chemoselective 15N tag for sensitive and high-resolution nuclear magnetic resonance profiling of the carboxyl-containing metabolome. Anal Chem 81:4882–4888PubMedGoogle Scholar
  97. 97.
    Ye T, Zhang S, Mo H et al (2010) 13C-formylation for improved NMR profiling of amino metabolites in biofluids. Anal Chem 82:2303–2309PubMedGoogle Scholar
  98. 98.
    DeSilva MA, Shanaiah N, Nagana Gowda GA et al (2009) Application of 31P NMR spectroscopy and chemical derivatization for metabolite profiling of lipophilic compounds in human serum. Magn Reson Chem 47:S74–S80PubMedGoogle Scholar
  99. 99.
    NaganaGowda GA, Tayyari F, Ye T et al (2010) Quantitative analysis of blood plasma metabolites using isotope enhanced NMR methods. Anal Chem 82:8983–8990Google Scholar
  100. 100.
    Fan TW (1996) Metabolite profiling by one- and two-dimensional NMR analysis of complex mixtures. Prog NMR Spectrosc 28:161–219Google Scholar
  101. 101.
    Hu K, Ellinger JJ, Chylla RA et al (2011) Measurement of absolute concentrations of individual compounds in metabolite mixtures by gradient-selective time-zero (1)H-(13)C HSQC with two concentration references and fast maximum likelihood reconstruction analysis. Anal Chem 83:9352–9360PubMedGoogle Scholar
  102. 102.
    Hu K, Wyche TP, Bugni TS et al (2011) Selective quantification by 2D HSQC(0) spectroscopy of thiocoraline in an extract from a sponge-derived Verrucosispora sp. J Nat Prod 74:2295–2298PubMedGoogle Scholar
  103. 103.
    Berg JM, Tymoczko JL, Stryer L (2002) Biochemistry. W. H. Freeman & Co, New YorkGoogle Scholar
  104. 104.
    Sakami W, Harrington H (1963) Amino acid metabolism. Annu Rev Biochem 32:355–398PubMedGoogle Scholar
  105. 105.
    Brosnan JT (2000) Glutamate, at the interface between amino acid and carbohydrate metabolism. J Nutr 130:988S–990SPubMedGoogle Scholar
  106. 106.
    Young VR, Ajami AM (2001) Glutamine: the emperor or his clothes? J Nutr 131:2449S–2459SPubMedGoogle Scholar

Copyright information

© Springer Science+Business Media Dordrecht 2012

Authors and Affiliations

  • G. A. Nagana Gowda
    • 1
    Email author
  • Narasimhamurthy Shanaiah
    • 1
  • Daniel Raftery
    • 1
  1. 1.Department of Anesthesiology and Pain Medicine, Mitochondria and Metabolism CenterUniversity of WashingtonSeattleUSA

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