Related Research on D-(+)-Cellobiose

Introduction

D-(+)-Cellobiose (Figure 1), a β-1,4-linked D-glucose disaccharide with a positive specific rotation, is a key intermediate in cellulose hydrolysis and a vital substrate for biomass biorefinery research. D-(+)-Cellobiose , which is the D-glucose dimer was chosen as a model compound for the initial phase of studies, as cellulose is insoluble in all common solvents and it is difficult to study the direct interactions of cellulose with acids in a heterogeneous phase.[1] 

Interactions of  D-(+)-Cellobiose with p-toluenesulfonic acid in aqueous solution

The effects of adding D₂SO₄, and p-toluenesulfonic acid-d to  D-(+)-Cellobiose dissolved in D₂O were investigated at 23°C by plotting (13)C NMR chemical shift changes (Δδ) against the acid to  D-(+)-Cellobiose molar ratio. (13)C Chemical shifts of all 18 carbon signals from α and β anomers of  D-(+)-Cellobiose showed gradual decreases due to increasing acidity in aqueous D₂SO₄ medium. The C-1 of the α anomer showed a slightly higher response to increasing D(+) concentration in the surrounding. In the aqueous p-toluenesulfonic acid-d medium, C-6' and C-4' carbons of both α, and β anomeric forms of  D-(+)-Cellobiose are significantly affected by increasing the sulfonic acid concentrations, and this may be due to a 1:1 interaction of p-toluenesulfonic acid-d with the C-6', C-4' region of the cellobiose molecule.[1]

Interactions of  D-(+)-Cellobiose with selected chloride salts

The interactions of cellulose model compound  D-(+)-Cellobiose with chloride salts of Zn²⁺, Ca²⁺, Li⁺, Sn²⁺, La³⁺, Mg²⁺, K⁺ and NH₄⁺ were evaluated by measuring the 13C NMR chemical shift changes (Δδ) of the disaccharide due to the addition of salts in D₂O. The KCl and NH₄Cl showed similar Δδ changes due to interactions only with the Cl^- anion. Whereas other chloride salts showed interactions with both cation and anion. Among these salts the total interactions are in the order: Zn²⁺>Sn²⁺>Li⁺>Ca²⁺~La³⁺>Mg²⁺. The FT-IR spectra of  D-(+)-Cellobiose-chloride salt 1:2 mixtures also indicate that KCl and NH₄Cl interacts similarly with  D-(+)-Cellobiose in the solid state.[2]

Effect of  D-(+)-Cellobiose on oral bioavailability of gentiopicroside

In this study，the effect of  D-(+)-Cellobiose on oral bioavailability of gentiopicroside ( GPS) was investigate. The influence of  D-(+)-Cellobiose on GPS was achieved by calculating the residual GPS after being degraded with β-glucosidase or intestinal flora，and the data demonstrated  D-(+)-Cellobiose could inhibit the degradation of GPS in intestines; in bioavailability experiment， D-(+)-Cellobiose could significantly improve the oral bioavailability ( P＜0. 05) of GPS at the mass ratio of 1∶ 5，1∶ 10 ( GPS- D-(+)-Cellobiose) .  D-(+)-Cellobiose applied in this study may improve the oral bioavailability of GPS through delaying the degradation in intestines.[3]

Recombinant Corynebacterium glutamicum under oxygen-deprived conditions

Corynebacterium glutamicum R was metabolically engineered to broaden its sugar utilization range to D-xylose and  D-(+)-Cellobiose contained in lignocellulose hydrolysates. The resultant recombinants expressed Escherichia coli xylA and xylB genes, encoding D-xylose isomerase and xylulokinase, respectively, for D-xylose utilization and expressed C. glutamicum R bglF317A and bglA genes, encoding phosphoenolpyruvate:carbohydrate phosphotransferase system (PTS) beta-glucoside-specific enzyme IIBCA component and phospho-beta-glucosidase, respectively, for  D-(+)-Cellobiose utilization. The genes were fused to the non-essential genomic regions distributed around the C. glutamicum R chromosome and were under the control of their respective constitutive promoter trc and tac that permitted their expression even in the presence of D-glucose. The enzyme activities of resulting recombinants increased with the increase in the number of respective integrated genes. Maximal sugar utilization was realized with strain X5C1 harboring five xylA-xylB clusters and one bglF317A-bglA cluster. In both  D-(+)-Cellobiose and D-xylose utilization, the sugar consumption rates by genomic DNA-integrated strain were faster than those by plasmid-bearing strain, respectively. In mineral medium containing 40 g l^-1 D-glucose, 20 g l^-1 D-xylose, and 10 g l^-1 D-(+)-Cellobiose, strain X5C1 simultaneously and completely consumed these sugars within 12 h and produced predominantly lactic and succinic acids under growth-arrested conditions.[4]

Hydrolysis and interactions of  D-(+)-Cellobiose with polycarboxylic acids

The hydrolysis of cellulose model compound  D-(+)-Cellobiose was studied with a series of eight common polycarboxylic acids and two monocarboxylic acids in aqueous medium using 0.500 mmol -COOH/L at 170 °C. The maleic acid showed the highest catalytic activity with turnover frequency (TOF) of 29.5 h -1. The interaction of carboxylic acids with  D-(+)-Cellobiose in DMSO-d 6 was studied by determination of the pseudo first-order rate constant k H of anomeric -OH exchange rate in cellobiose using 1H NMR spectroscopy. The maleic, oxalic and citric acids showed infinitely large k H values indicating very strong interactions with  D-(+)-Cellobiose. The next highest interactions were found with phthalic acid (kH = 248.8 Hz). The FT-IR studies showed significant carboxylic acid C=O stretching frequency shifts (ΔνC=O) of 12, 13 and 10 cm-1 for maleic, oxalic and acetic acids respectively in mixtures with  D-(+)-Cellobiose.[5]

References

[1] Amarasekara AS, Owereh OS, Ezeh B. Interactions of D-cellobiose with p-toluenesulfonic acid in aqueous solution: a (13)C NMR study. Carbohydr Res. 2011;346(17):2820-2822. doi:10.1016/j.carres.2011.09.032

[2] Amarasekara AS, Wiredu B. Interactions of D-cellobiose with selected chloride salts: A ¹³C NMR and FT-IR study. Spectrochim Acta A Mol Biomol Spectrosc. 2016;159:113-116. doi:10.1016/j.saa.2016.01.048

[3] Dai YH,et al.Effect of D-cellobiose on oral bioavailability of gentiopicroside[J].China Journal of Chinese Materia Medica,2016,41(10):1855-1859.

[4] Sasaki M, Jojima T, Inui M, Yukawa H. Simultaneous utilization of D-cellobiose, D-glucose, and D-xylose by recombinant Corynebacterium glutamicum under oxygen-deprived conditions. Appl Microbiol Biotechnol. 2008;81(4):691-699. doi:10.1007/s00253-008-1703-z

[5] Amarasekara AS, Wiredu B, Lawrence YM. Hydrolysis and interactions of d-cellobiose with polycarboxylic acids. Carbohydr Res. 2019;475:34-38. doi:10.1016/j.carres.2019.02.002

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