Structural identification of nonvolatile dimerization products of glucosamine by gas chromatography-mass spectrometry, liquid chromatography-mass spectrometry, and nuclear magnetic resonance analysis

Mira Jun, Yu Shao, Chi-Tang Ho, Uwe Koetter, Stanley Lech

Research output: Contribution to journalArticle

27 Scopus citations

Abstract

The degradation profile of glucosamine bulk form stressed at 100 °C for 2 h in an aqueous solution was studied. Column chromatography of acetylated product mixture led to isolation of two pure compounds (1 b and 2b) and a mixture of at least three isomers (3b). 1 a and 2a were identified as 5-(hydroxymethyl)-2-furaldehyde (5-HMF) and 2-(tetrahydroxybutyl)-5-(3′ ,4′-dihydroxy-1′-trans-butenyl)-pyrazine, respectively, by utilizing a variety of analytical techniques, such as GC-MS, LC-MS, on-line UV spectrum, 1H and 13C NMR, and DEPT, as well as 1H-1H COSY. 3a was identified as 2-(tetrahydroxybutyl)-5-(2′,3′,4′-trihydroxybutyl)pyrazine, commonly known as deoxyfructosazine. In addition, glucosamine solid dosage form was exposed to 40 °C/75% relative humility for 10 weeks. Methanol extract of glucosamine solid dosage form was analyzed after acetylation by LC-MS, resulting in degradants 3b and 4b. 3a and 4a were, therefore, determined as deoxyfructosazine and 2,5-bis-(tetrahydroxybutyl)pyrazine (fructosazine), respectively. Furthermore, the mechanisms of formation of identified degradation products are proposed and briefly discussed.

Original languageEnglish (US)
Pages (from-to)6340-6346
Number of pages7
JournalJournal of Agricultural and Food Chemistry
Volume51
Issue number21
DOIs
StatePublished - Oct 8 2003

All Science Journal Classification (ASJC) codes

  • Chemistry(all)
  • Agricultural and Biological Sciences(all)

Keywords

  • 2-amino-2-deoxy-D-glucose
  • Degradation
  • GC-MS
  • Glucosamine
  • LC-MS
  • NMR
  • Solid dosage form

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