title: Development of an Analytic Method for Sulfur Compounds in Aged Garlic Extract with the Use of a Postcolumn High Performance Liquid Chromatography Method with Sulfur-Specific Detection.
abstract: BACKGROUND
  Garlic and its processed preparations contain numerous sulfur compounds that are difficult to analyze in a single run using HPLC.
  
  
  OBJECTIVE
  The aim of this study was to develop a rapid and convenient sulfur-specific HPLC method to analyze sulfur compounds in aged garlic extract (AGE).
  
  
  METHODS
  We modified a conventional postcolumn HPLC method by employing a hexaiodoplatinate reagent. Identification and structural analysis of sulfur compounds were conducted by LC-mass spectrometry (LC-MS) and nuclear magnetic resonance. The production mechanisms of cis-S-1-propenylcysteine (cis-S1PC) and S-allylmercaptocysteine (SAMC) were examined by model reactions.
  
  
  RESULTS
  Our method has the following advantages: less interference from nonsulfur compounds, high sensitivity, good correlation coefficients (r > 0.98), and high resolution that can separate >20 sulfur compounds, including several isomers, in garlic preparations in a single run. This method was adapted for LC-MS analysis. We identified cis-S1PC and γ-glutamyl-S-allyl-mercaptocysteine in AGE. The results of model reactions suggest that cis-S1PC is produced from trans-S1PC through an isomerization reaction and that SAMC is produced by a reaction involving S-allylcysteine/S1PC and diallyldisulfide during the aging period.
  
  
  CONCLUSIONS
  We developed a rapid postcolumn HPLC method for both qualitative and quantitative analyses of sulfur compounds, and this method helped elucidate a potential mechanism of cis-S1PC and SAMC action in AGE.
authors.affiliation: Drug Discovery Laboratory, Wakunaga Pharmaceutical Co., Ltd., Akitakata, Japan.
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Matsutomo
authors.affiliation: Drug Discovery Laboratory, Wakunaga Pharmaceutical Co., Ltd., Akitakata, Japan kodera_y@wakunaga.co.jp.
authors.forename: Yukihiro
authors.initials: Y
authors.lastname: Kodera
mesh_terms: D000498:Allyl Compounds / Q000032:analysis; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D003545:Cysteine / Q000031:analogs & derivatives / Q000032:analysis; D004220:Disulfides / Q000032:analysis; D005737:Garlic / Q000737:chemistry*; D006801:Humans; D007536:Isomerism; D013058:Mass Spectrometry / Q000379:methods; D010936:Plant Extracts / Q000737:chemistry*; D013455:Sulfur / Q000032:analysis*; D013457:Sulfur Compounds / Q000032:analysis*
chemical_list: D000498:Allyl Compounds; D004220:Disulfides; D010936:Plant Extracts; C086300:S-allylmercaptocysteine; D013457:Sulfur Compounds; C028009:diallyl disulfide; D013455:Sulfur; C065299:S-allylcysteine; D003545:Cysteine
keywords: S-1-propenylcysteine; S-allylmercaptocysteine; aged garlic extract; garlic; hexaiodoplatinate reagent; postcolumn HPLC; sulfur compound