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Polysaccharides
Published in Stanislaw Penczek, H. R. Kricheldorf, A. Le Borgne, N. Spassky, T. Uryu, P. Klosinski, Models of Biopolymers by Ring-Opening Polymerization, 2018
An anhydro-ribose has been known for a long time,60 and Hughes and Speakman examined in detail the preparation of 1,5-anhydro 2,3-O-isopropylidene-d-ribofuranose by reaction of d-ribose and acetone.54 By reaction of d-ribose, benzaldehyde, and an acid catalyst, 1,5-anhydro-2,3-O-benzylidene-β-d-ribofuranose is also prepared in a low yield.60,125 Since d-ribose has two hydroxyls in cis position, it readily forms an anhydro ring as well as the alkylidene group between these hydroxyls. Köll and co-workers synthesized the corresponding 1,5-anhydro-pentofuranoses by vacuum pyrolysis of ribose, xylose, lyxose, and arabinose in low yields of 2 to 5%.63
Biochemistry
Published in W. M. Haynes, David R. Lide, Thomas J. Bruno, CRC Handbook of Chemistry and Physics, 2016
W. M. Haynes, David R. Lide, Thomas J. Bruno
Panose Paratose Primeverose Psicose Quinovose Common name Symbol Systematic name - -Glucopyranosyl-(16)-- -glucopyranosyl-(14)- -glucose 3,6-Dideoxy- -ribo-hexose - -Xylopyranosyl-(16)- -glucose ribo-Hex-2-ulose 6-Deoxyglucose - -Fructofuranosyl-- -galactopyranosyl-(16)-- glucopyranoside 6-Deoxymannose 2,3,6-Trideoxy- -threo-hexose ribo-Pentose erythro-Pent-2-ulose - -Rhamnopyranosyl-(16)- -glucose 2,6-Dideoxy-3-O-methyl- -xylo-hexose -altro-Hept-2-ulose xylo-Hex-2-ulose 5-Deoxy-3-C-formyl- -lyxose - -Fructofuranosyl-- -glucopyranoside lyxo-Hex-2-ulose talo-Hexose - -Glucopyranosyl-(13)- -fructose 3,6-Dideoxy- -arabino-hexose xylo-Pentose threo-Pent-2-ulose
Cloning, expression, and characterization of an arabitol dehydrogenase and coupled with NADH oxidase for effective production of L-xylulose
Published in Preparative Biochemistry & Biotechnology, 2022
Chen-Yuan Zhu, Yi-Hao Zhu, Hua-Ping Zhou, Yuan-Yuan Xu, Jian Gao, Ye-Wang Zhang
There are two methods for the production of L-xylulose: chemical and biological routes. In the chemical process, the L-xylulose synthesis could be practiced through refluxing in dry pyridine using L-ribulose as a raw material[9] or from D-sorbitol via cascade oxidations.[10] However, the chemical synthetic method has the disadvantages of complex production route, low product yield, high environmental pollution, and difficult to be separated from other isomers.[12] The approaches of biotransformation for L-xylulose production could be achieved using pentose isomerases for isomerizing L-xylose or L-lyxose.[13] One of these pentose isomerases, L-arabinitol 4-dehydrogenase (LAD) was cloned from Trichoderma reesei and expressed in Saccharomyces cerevisiae by Richard et al.[14] Although it is possible to produce L-xylulose by conversion using L-arabinitol, the biotransformation with LAD is not of high applicability due to L-lyxose and L-arabinitol are difficult to obtain owing to their extremely small quantities in nature. Another key enzyme, xylitol dehydrogenase (XDH) has been cloned from B. pallidus[15] or P. ananatis[16] and overexpressed to produce L-xylulose, in which the substrate xylitol was available and affordable. However, the thermodynamic equilibrium of XDH catalyzed reaction is not favorable for L-xylulose production due to nicotinamide adenine dinucleotide (NADH) inhibition.[17] Whereas, it has not been characterized as a limiting factor for Arabitol dehydrogenase (ArDH), which is also considered as a biocatalyst to produce the L-xylulose.[18] ArDH, which belongs to short-chain dehydrogenases, can catalyze the biotransformation to produce L-xylulose from xylitol.[19,20] Most dehydrogenases for the L-xylulose production require nicotinamide adenine dinucleotide (NAD+), an expensive nicotinamide cofactor, and this is also a bottleneck for the application potential of ArDH.