Identification of new derivatives of sinigrin and glucotropaeolin produced by the human digestive microflora using 1H NMR spectroscopy analysis of in vitro incubations.

One- and two-dimensional (1)H NMR spectroscopy were used to study the biotransformation of two dietary glucosinolates, sinigrin (SIN), and glucotropaeolin (GTL) by the human digestive microflora in vitro. The molecular structures of the new metabolites issued from the aglycone moiety of the glucosinolate were identified, and the modulation of carbon metabolism was studied by quantifying bacterial metabolites issued from the xenobiotic incubation in the presence or absence of a source of free glucose. Unambiguously and for the first time, it was shown that SIN and GTL were transformed quantitatively into allylamine and benzylamine, respectively. The comparison of the kinetics of transformation of SIN and GTL with and without glucose clearly showed that the presence of glucose did not modify either the nature of the metabolites or the rate of transformation of the glucosinolates (complete degradation within 30 h). The main end products of the glucose moiety of glucosinolates were characteristic of anaerobic carbon metabolism in the digestive tract (acetate, lactate, ethanol, propionate, formate, and butyrate) and similar to those released from free glucose. This work represents the first application of (1)H NMR spectroscopy to the study of xenobiotic metabolism by the human digestive microflora, demonstrating allyl- and benzylamine production from glucosinolates. Whether these amines are produced in vivo from dietary glucosinolates remains to be established. This would reduce the availability of other glucosinolate metabolites, notably cancer-protective isothiocyanates.

[1]  S. Rabot,et al.  Formation of allyl isothiocyanate from sinigrin in the digestive tract of rats monoassociated with a human colonic strain of Bacteroides thetaiotaomicron. , 2001, FEMS microbiology letters.

[2]  J. Otte,et al.  Absorption and Degradation of Individual Intact Glucosinolates in the Digestive Tract of Rodents , 1994 .

[3]  M. Sancelme,et al.  Degradation of morpholine and thiomorpholine by an environmental Mycobacterium involves a cytochrome P450. Direct evidence of intermediates by in situ NMR , 1998 .

[4]  M. Sancelme,et al.  Morpholine Degradation Pathway of Mycobacterium aurumMO1: Direct Evidence of Intermediates by In Situ 1H Nuclear Magnetic Resonance , 1998, Applied and Environmental Microbiology.

[5]  A. Delort,et al.  Re-investigation of glucose metabolism in Fibrobacter succinogenes, using NMR spectroscopy and enzymatic assays. Evidence for pentose phosphates phosphoketolase and pyruvate formate lyase activities. , 1997, Biochimica et biophysica acta.

[6]  T. Miller,et al.  NMR detection of 13CH313COOH from 3-13C-glucose: a signature for Bifidobacterium fermentation in the intestinal tract. , 1998, The Journal of nutrition.

[7]  A. Delort,et al.  13C and 1H Nuclear Magnetic Resonance Study of Glycogen Futile Cycling in Strains of the Genus Fibrobacter , 1998, Applied and Environmental Microbiology.

[8]  S. Rabot,et al.  Glucosinolates and Glucosinolate Derivatives: Implications for Protection Against Chemical Carcinogenesis , 1994, Nutrition Research Reviews.

[9]  D. W. Ribbons,et al.  Biotransformations monitored in situ by proton nuclear magnetic resonance spectroscopy. , 2000, Trends in biotechnology.

[10]  T. Fan.  Metabolite profiling by one- and two-dimensional NMR analysis of complex mixtures , 1996 .

[11]  William S. Price,et al.  Water Signal Suppression in NMR Spectroscopy , 1999 .

[12]  I. Wilson,et al.  1H and 2H NMR spectroscopic studies on the metabolism and biochemical effects of 2-bromoethanamine in the rat. , 1995, Biochemical pharmacology.

[13]  H. Frank,et al.  Bacterial degradation of benzyl isothiocyanate. , 1972, Applied microbiology.

[14]  H. Fukui,et al.  Theory and calculation of nuclear shielding constants , 1997 .

[15]  R. Heaney,et al.  Glucosinolates and their breakdown products in food and food plants. , 1983, Critical reviews in food science and nutrition.

[16]  F. Chung,et al.  Conversion of glucosinolates to isothiocyanates in humans after ingestion of cooked watercress. , 1999, Cancer epidemiology, biomarkers & prevention : a publication of the American Association for Cancer Research, cosponsored by the American Society of Preventive Oncology.

[17]  I. Wilson,et al.  1H and 19F-nmr spectroscopic studies on the metabolism and urinary excretion of mono- and disubstituted phenols in the rat. , 1996, Xenobiotica; the fate of foreign compounds in biological systems.

[18]  Assignment of overlapping (1)H NMR signals in carp seminal plasma by proton-detected 2D C,H correlation spectroscopy. , 2000, Biochemical and biophysical research communications.

[19]  Rudi H. Vos,et al.  The effect of processing conditions on glucosinolates in cruciferous vegetables , 1988, Zeitschrift fur Lebensmittel-Untersuchung und -Forschung.

[20]  E. Neidle,et al.  Novel nuclear magnetic resonance spectroscopy methods demonstrate preferential carbon source utilization by Acinetobacter calcoaceticus , 1996, Journal of bacteriology.

[21]  T. Miller,et al.  Changes of Fermentation Pathways of Fecal Microbial Communities Associated with a Drug Treatment That Increases Dietary Starch in the Human Colon , 1999, Applied and Environmental Microbiology.

[22]  D. A. Cooper,et al.  1H nuclear magnetic resonance of heroin's D ring. , 1985, Journal of forensic sciences.

[23]  M. Sancelme,et al.  Common Degradative Pathways of Morpholine, Thiomorpholine, and Piperidine by Mycobacterium aurum MO1: Evidence from1H-Nuclear Magnetic Resonance and Ionspray Mass Spectrometry Performed Directly on the Incubation Medium , 2000, Applied and Environmental Microbiology.

[24]  J C Lindon,et al.  Application of pattern recognition methods to the analysis and classification of toxicological data derived from proton nuclear magnetic resonance spectroscopy of urine. , 1991, Molecular pharmacology.

[25]  T. Shapiro,et al.  Human metabolism and excretion of cancer chemoprotective glucosinolates and isothiocyanates of cruciferous vegetables. , 1998, Cancer epidemiology, biomarkers & prevention : a publication of the American Association for Cancer Research, cosponsored by the American Society of Preventive Oncology.

[26]  M. Sancelme,et al.  Degradation of Morpholine by an EnvironmentalMycobacterium Strain Involves a Cytochrome P-450 , 1998, Applied and Environmental Microbiology.

[27]  R A Goldbohm,et al.  A review of mechanisms underlying anticarcinogenicity by brassica vegetables. , 1997, Chemico-biological interactions.

[28]  Ian D. Wilson,et al.  HIGH RESOLUTION PROTON MAGNETIC RESONANCE SPECTROSCOPY OF BIOLOGICAL FLUIDS , 1989 .

[29]  G. Macfarlane,et al.  Carbohydrate Fermentation, Energy Transduction and Gas Metabolism in the Human Large Intestine , 1997 .

[30]  W. Jongen.  Glucosinolates in Brassica: Occurrence and significance as cancer-modulating agents , 1996, Proceedings of the Nutrition Society.

[31]  I. Wilson,et al.  Nuclear magnetic resonance and high-performance liquid chromatography-nuclear magnetic resonance studies on the toxicity and metabolism of ifosfamide. , 1996, Therapeutic drug monitoring.

[32]  H. Weber,et al.  Online NMR for monitoring biocatalysed reactions. , 2000, Current opinion in biotechnology.

[33]  I. Johnson,et al.  Allyl isothiocyanate is selectively toxic to transformed cells of the human colorectal tumour line HT29. , 1993, Carcinogenesis.

[34]  S. Rabot,et al.  Rape-seed meal toxicity in gnotobiotic rats: influence of a whole human faecal flora or single human strains of Escherichia coli and Bacteroides vulgatus , 1993, British Journal of Nutrition.