32706-29-9

Upstream product

• 87-72-9 D-Xylose 
• 95-54-5 1,2-diamino-benzene 
• 53106-52-8 DL-xylose 
• 302-72-7 rac-Ala-OH 
• 6401-81-6 maltotriose 
• 42015-35-0 2-hydroxymethyl-3-(2',3'-dihydroxypropyl)quinoxaline 

Relevant academic research and scientific papers

Formation of α-dicarbonyl compounds in beer during storage of pilsner

With the aim of determining the formation of α-dicarbonyl intermediates during beer aging on the shelf, α-dicarbonyls were identified and quantified after derivatization with 1,2-diaminobenze to generate quinoxalines. The sensory effects of α-dicarbonyls

3-Deoxypentosulose: An α-dicarbonyl compound predominating in nonenzymatic browning of oligosaccharides in aqueous solution

The thermal degradation of D-glucose, maltose, and maltotriose in aqueous solution was investigated under caramelization (no glycine) and Maillard (with glycine) conditions. Degradation of the sugar and α-dicarbonyls product was monitored. Under both caramelization and Maillard reaction conditions, 3-deoxypentosulose was the predominating α-dicarbonyl compound formed from maltose and maltotriose. In the absence of an amino compound, however, 3-deoxypentosulose is formed in much lower concentration. It was concluded that 3-deoxypentosulose is formed by a pathway specific for oligo- and polysaccharides since this α-dicarbonyl is formed from the α-1→4 glucans such as maltose and maltotriose but not from glucose. For its formation, a retro Claisen reaction of an enolization product of 1-amino-1,4-dideoxyhexosulose is proposed as the route to its formation. 1-Amino-1,4-dideoxyhexosulose could be formed by vinylogous α-elimination from the 2,3-enediol structure after Amadori rearrangement, favored by planar alignment of the bonds between C1 and C4. Subsequent rearrangement by keto - enoltautomerization leads to a 1-imino-3-keto structure. In this structure, attack of a hydroxyl anion, provided by water at neutral pH, could cause a splitting off of the C1. This reaction gives rise to formic acid or formamide and a pentose derivative, which reacts further to give 3-deoxypentosulose.

Structural Changes of Quinoxaline Derivatives, with Special Reference to 2-(2',3'-Dihydroxypropyl)-3-hydroxymethylquinoxaline in Alakaline and Acidic Solutions

Conversion products of 2-(2',3'-dihydroxypropyl)-3-hydroxymethylquinoxaline under alkaline and acidic refluxed conditions were characterized using GLC, GC-MS, HPLC, and NMR measurements.In an alkaline solution (pH 10, carbonate buffer), 2-(2',3'-dihydroxypropyl)-3-methylquinoxaline (GA-1) and 2-(2',3'-dihydroxypropyl)quinoxaline were produced in yields of 16percent and 19percent, respectively, whereas in an acidic solution (MeOH-AcOH-H2O=4:5:2), a large amount (65percent) of 3,4-dihydro-1H-pyranoquinoxalin-3-yl methanol and a small amount (5percent) of GA-1 were obtained.These results suggest that the C-C linkage of the side chain in the quinoxaline readily splits in alkaline solutions, whereas in acidic solutions no such splitting can be observed, but condensation or dehydration occurs between hydroxyl groups of the side chains, or the hydroxymethyl group is reduced to a methyl group.

Quinoxalines Derived from D-Xylose and o-Phenylendiamine under Acidic Refluxed Conditions

Quinoxalines derived from D-xylose and o-phenylenediamine (OPD) in an acidic medium under reflux were studied, using GLC, GC-MS and NMR measurements.Three quinoxaline derivatives (XA-I, XA-II and G-2) were separated from the reaction mixture of D-xylose with OPD (0.2 mol, each) in a 46percent total yield.Their approximate molar ratio was 3:3:2.Two newly isolated XA-I and XA-II derivatives were identified as 2-methyl-3(2'-hydroxyethyl)quinoxaline and 2-(1',2',3'-trihydroxypropyl)quinoxaline, respectively.The other was G-2 , which has previously been obtained from D-glucose or D-xylose in an alkaline solution.XA-I may be regarded as a partially reduced form of G-2 at the side chain of the quinoxaline, with XA-II as an oxidized form.A possible mechanism for quinoxaline formation is discussed.