title: In vitro metabolic conversion of the organic breakdown products of glucosinolate to goitrogenic thiocyanate anion.
abstract: BACKGROUND
  Glucosinolates are abundant in Brassicaceae vegetables, and they are degraded into various organic breakdown products (BPs) (R-CN, -NCS and -SCN) by myrosinase when plant tissues are damaged. This study was designed to investigate whether these BPs could be broken further into goitrogenic thiocyanate anions (SCN(-) ) metabolically and/or spontaneously. Ten glucosinolates were chosen for this study based on the various structures of their side chains. SCN(-) and cyanide anions (CN(-) ) liberated from the BPs of these glucosinolates were quantified after incubation with human liver S9 and rhodanese.
  
  
  RESULTS
  Upon treatment with metabolic enzymes, CN(-) was produced from all organic thiocyanates, aliphatic and benzyl nitriles, then a substantial amount of produced CN(-) was further metabolized to SCN(-) by rhodanese. All organic thiocyanates and allyl isothiocyanate were metabolized to produce SCN(-), without involving CN(-) production. Spontaneous degradation to SCN(-) in an aqueous environment was observed only in 4-(methylthio)butyl thiocyanate, though the enzymatic reaction rate exceeded the spontaneous one. Among these BPs, the major source of SCN(-) was organic thiocyanates.
  
  
  CONCLUSIONS
  The results show that some organic nitriles, organic thiocyanates and allyl isothiocyanate may be regarded as potential sources of SCN(-) through metabolism when people ingest glucosinolate-containing vegetables.
authors.affiliation: Department of Food and Nutrition, Seoul National University, Seoul, 151-742, Korea.
authors.forename: Juyoung
authors.initials: J
authors.lastname: Lee
authors.affiliation: Department of Food and Nutrition, Seoul National University, Seoul, 151-742, Korea.|Research Institute of Human Ecology, Seoul National University, Seoul, 151-742, Korea.
authors.forename: Hoonjeong
authors.initials: H
authors.lastname: Kwon
mesh_terms: D000838:Anions / Q000378:metabolism*; D013956:Antithyroid Agents / Q000378:metabolism*; D019607:Brassicaceae / Q000737:chemistry*; D005961:Glucosinolates / Q000378:metabolism*; D006026:Glycoside Hydrolases / Q000378:metabolism; D006801:Humans; D006868:Hydrolysis; D066298:In Vitro Techniques; D017879:Isothiocyanates / Q000378:metabolism*; D008099:Liver / Q000378:metabolism*; D009570:Nitriles / Q000378:metabolism; D010940:Plant Proteins / Q000378:metabolism; D013861:Thiocyanates / Q000378:metabolism*; D013884:Thiosulfate Sulfurtransferase / Q000378:metabolism
chemical_list: D000838:Anions; D013956:Antithyroid Agents; D005961:Glucosinolates; D017879:Isothiocyanates; D009570:Nitriles; D010940:Plant Proteins; D013861:Thiocyanates; C004471:allyl isothiocyanate; D013884:Thiosulfate Sulfurtransferase; D006026:Glycoside Hydrolases; C022739:thioglucosidase; C031760:thiocyanate
keywords: breakdown products; cyanide anion; glucosinolate; goitrogen; in vitro metabolism; thiocyanate anion