title: Alkyl pyrazine synthesis via an open heated bath with variable sugars, ammonia, and various amino acids.
abstract: BACKGROUND
  Semi-quantitative characteristics of headspace volatile pyrazines which constituted around 1% by weight of the final product have been previously described. The influence of reactant concentration, reaction temperature, and reaction time on both the yield of total alkyl pyrazines and the distribution pattern of specific identified pyrazines has not been reported.
  
  
  RESULTS
  The optimum synthetic conditions were 5 mol L-1NH4OH, 2 mol L-1rhamnose, 0.5 mol L-1leucine at 110°C for 2 h. The greatest total amount of pyrazines obtained was 17 280 µg of extracted product which translated into 31% 2,6-dimethyl pyrazine, 17% 2-methyl pyrazine, 15% 2-ethyl-6-methyl pyrazine, and 16% 2-isoamyl-6-methyl pyrazine.
  
  
  CONCLUSIONS
  The yield of synthesized pyrazines increased at higher temperatures. Quantitative total and specific pyrazine results as opposed to analysis of only headspace volatiles are more representative of pyrazine synthesis. © 2016 Society of Chemical Industry.
authors.affiliation: Department of Chemistry, Virginia Tech, Blacksburg, VA, 24061-0212, USA.
authors.forename: Katayoun Mahdavi
authors.initials: KM
authors.lastname: Ara
authors.affiliation: Department of Chemistry, Virginia Tech, Blacksburg, VA, 24061-0212, USA.
authors.forename: Larry T
authors.initials: LT
authors.lastname: Taylor
authors.affiliation: Department of Chemistry, Virginia Tech, Blacksburg, VA, 24061-0212, USA.
authors.forename: Mehdi
authors.initials: M
authors.lastname: Ashraf-Khorassani
authors.affiliation: iii Consulting, LLC, 210 Jessamine St, Conway, SC, 29626, USA.
authors.forename: William M
authors.initials: WM
authors.lastname: Coleman
mesh_terms: D000596:Amino Acids / Q000737:chemistry*; D000641:Ammonia / Q000737:chemistry*; D008401:Gas Chromatography-Mass Spectrometry; D006358:Hot Temperature; D015416:Maillard Reaction; D011719:Pyrazines / Q000138:chemical synthesis / Q000737:chemistry*; D012210:Rhamnose / Q000737:chemistry*
chemical_list: D000596:Amino Acids; D011719:Pyrazines; D000641:Ammonia; D012210:Rhamnose
keywords: GC-MS; alkyl pyrazines; amino acids; open heated bath; rhamnose