13074-08-3Relevant articles and documents
Efficient enzymatic synthesis of l-rhamnulose and l-fuculose
Wen, Liuqing,Zang, Lanlan,Huang, Kenneth,Li, Shanshan,Wang, Runling,Wang, Peng George
, p. 969 - 972 (2016)
l-Rhamnulose (6-deoxy-l-arabino-2-hexulose) and l-fuculose (6-deoxy-l-lyxo-2-hexulose) were prepared from l-rhamnose and l-fucose by a two-step strategy. In the first reaction step, isomerization of l-rhamnose to l-rhamnulose, or l-fucose to l-fuculose was combined with a targeted phosphorylation reaction catalyzed by l-rhamnulose kinase (RhaB). The by-products (ATP and ADP) were selectively removed by silver nitrate precipitation method. In the second step, the phosphate group was hydrolyzed to produce l-rhamnulose or l-fuculose with purity exceeding 99% in more than 80% yield (gram scale).
Molecular characterization of a thermostable l-fucose isomerase from Dictyoglomus turgidum that isomerizes l-fucose and d-arabinose
Hong, Seung-Hye,Lim, Yu-Ri,Kim, Yeong-Su,Oh, Deok-Kun
experimental part, p. 1926 - 1934 (2012/09/22)
A recombinant thermostable l-fucose isomerase from Dictyoglomus turgidum was purified with a specific activity of 93 U/mg by heat treatment and His-trap affinity chromatography. The native enzyme existed as a 410 kDa hexamer. The maximum activity for l-fucose isomerization was observed at pH 7.0 and 80 °C with a half-life of 5 h in the presence of 1 mM Mn2+ that was present one molecular per monomer. The isomerization activity of the enzyme with aldose substrates was highest for l-fucose (with a kcat of 15,500 min-1 and a Km of 72 mM), followed by d-arabinose, d-altrose, and l-galactose. The 15 putative active-site residues within 5 A of the substrate l-fucose in the homology model were individually replaced with other amino acids. The analysis of metal-binding capacities of these alanine-substituted variants revealed that Glu349, Asp373, and His539 were metal-binding residues, and His539 was the most influential residue for metal binding. The activities of all variants at 349 and 373 positions except for a dramatically decreased kcat of D373A were completely abolished, suggesting that Glu349 and Asp373 were catalytic residues. Alanine substitutions at Val131, Met197, Ile199, Gln314, Ser405, Tyr451, and Asn538 resulted in substantial increases in Km, suggesting that these amino acids are substrate-binding residues. Alanine substitutions at Arg30, Trp102, Asn404, Phe452, and Trp510 resulted in decreases in kcat, but had little effect on Km.
Conversion of l-rhamnose into ten of the sixteen 1- and 6-deoxyketohexoses in water with three reagents: d-tagatose-3-epimerase equilibrates C3 epimers of deoxyketoses
Gullapalli, Pushpakiran,Yoshihara, Akihide,Morimoto, Kenji,Rao, Devendar,Akimitsu, Kazuya,Jenkinson, Sarah F.,Fleet, George W.J.,Izumori, Ken
supporting information; experimental part, p. 895 - 898 (2010/05/03)
The efficient isomerization of l-rhamnose [the only cheaply available deoxy hexose] to 1-deoxy-l-psicose, 1-deoxy-d-psicose, 1-deoxy-l-fructose, 1-deoxy-d-fructose, 1-deoxy-l-tagatose, 6-deoxy-l-psicose, 6-deoxy-d-psicose, 6-deoxy-l-fructose, 6-deoxy-d-fructose, and 6-deoxy-l-tagatose is described. The conversion of rhamnose to ten of the sixteen 1- and 6-deoxyketohexoses is accomplished in water in three steps. The range of substrates for d-tagatose-3-epimerase (DTE) is extended to 1- and 6-deoxyketoses. An authentic sample of 6-deoxy-d-psicose is prepared from d-psicose.
