CHEMISTRY-A EUROPEAN JOURNAL
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2024
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IF 3.9
Limin Ren,Yuxuan Xiao,Rameswar Bhattacharjee,Jingjing Wu,Pengyi Tang,Stavros Caratzoulas,Changgong Meng,Qiang Guo,Michael Tsapatsis
Graphical Bifunctional Ti-B-Beta zeolite is demonstrated to be an efficient catalyst for sorbose production via glucose isomerization. Ethanol directs the conformation of glucose, facilitating its selective isomerization to sorbose and enables this isomerization to surpass the thermodynamic equilibrium limit by engaging in reactions with the resultant sorbose. D-Glucose-to-L-sorbose isomerization on Lewis acidic zeolite is a highly attractive avenue for sorbose production. But the L-sorbose yield is limited by the competing D-glucose-to-D-fructose isomerization and reaction equilibrium. In this work, it is suggested that ethanol directs the glucose conformation for selective D-glucose-to-L-sorbose isomerization. It also reacts with the produced L-sorbose to form ethyl-sorboside, which allows the D-glucose-to-L-sorbose isomerization to proceed beyond the thermodynamic equilibrium limit. It is shown that a bifunctional zeolite Beta containing framework titanium (Ti) and boron (B) is a selective catalyst for this tandem reaction: Lewis acidic framework Ti catalyzes the D-glucose-to-L-sorbose isomerization via an intramolecular 5,1-hydride shift process as confirmed by isotopic tracing experiments followed by 13 C-NMR, while weak Brønsted acid framework B selectively promotes the sorbose ketalization with ethanol. A remarkably high yield of L-sorbose with a high fraction of sugar (>95 %: 27 % unreacted glucose, 11.4 % fructose, 57 % sorbose) was obtained after the mixture produced in ethanol was hydrolyzed.
研究领域:
化学工程
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催化科学
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DOI
高影响因子
RSC Advances
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2016
·Vol. 6
·期 106
·104193-104200
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IF 3.289
Lili Lv,Lijuan Wang,Yanan Zou,Rui Chen,Jiaojiao Yu
A chiral nonaqueous capillary electrophoresis (NACE) method using L-sorbose–boric acid complexes as the chiral ion-pair selectors was developed for enantioseparation of nineteen chiral analytes including eight β-blockers, seven β-agonists, two phenothiazines antihistamines, and two fluoroquinolone antibiotics. The effects of L-sorbose and boric acid concentrations, triethylamine concentration, applied voltage, and capillary temperature on the enantioseparation were systematically investigated. Under the optimized conditions, thirteen pairs of enantiomers were baseline resolved and five pairs of enantiomers were partially enantioseparated. Salbutamol showed a sign of separation with a shoulder peak. A reversal of propranolol enantiomer migration orders took place in the case when different concentrations of triethylamine were added into the NACE running buffers. The mass spectrometry (MS) results confirmed that triethylamine could promote the formation of negatively charged L-sorbose–boric acid complex chiral counter ions with different complex ratios. The enantioseparation results were compared with the previous work. Calibration curves showed excellent linearity with square of correlation coefficients (r2) greater than 0.9994 over concentration ranges of 5.0–500.0 μg mL−1 for each enantiomer of clenbuterol and esmolol, and 12.5–500.0 μg mL−1 for that of metoprolol. The limits of detection (LODs) and limits of quantitation (LOQs) for each enantiomer were 0.4–1.25 μg mL−1 and 1.5–4.0 μg mL−1, respectively. The relative standard deviations (RSDs) of intra-day and inter-day precisions of migration times were ≤1.64% (n = 6), and ≤6.54% (n = 15), respectively. The peak areas were ≤4.03% (n = 6), and ≤3.92% (n = 15), respectively. This method can likely be applied to the determination of each enantiomer in pharmaceutical formulations.
研究领域:
分析化学
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药物分析
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DOI
高影响因子
BIOORGANIC CHEMISTRY
·
2024
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IF 4.5
Muhammad Waheed Iqbal,Xinrui Tang,Tahreem Riaz,Shahid Mahmood,Yufei Zhang,Mei Zhao,Junhua Yun,Jia Li,Xianghui Qi
6-Deoxy- l -sorbose (6-DLS) is an imperative rare sugar employed in food, agriculture, pharmaceutical and cosmetic industeries. However, it is a synthetic and very expensive rare sugars, previously synthesized by chemo-enzymatic methods through a long chain of chemical processes. Recently, enzymatic synthesis of rare sugars has attracted a lot of attention due to its advantages over synthetic methods. In this work, a promising approach for the synthesis of 6-DLS from an inexpensive sugar l -fucose was identified. The genes for l -fucose isomerase from Paenibacillus rhizosphaerae (Pr-LFI) and genes for d -tagatose-3-epimerase from Caballeronia fortuita (Cf-DTE) have been used for cloning and co-expression in Escherichia coli , developed a recombinant plasmid harboring pANY1-Pr-LFI/Cf-DTE vector. The recombinant co-expression system exhibited an optimum activity at 50 °C of temperature and pH 6.5 in the presence of Co 2+ metal ion which inflated the catalytic activity by 6.8 folds as compared to control group with no metal ions. The recombinant co-expressed system was stable up to more than 50 % relative activity after 12 h and revealed a melting temperature (T m ) of 63.38 °C exhibiting half-life of 13.17 h at 50 °C. The co-expression system exhibited, 4.93, 11.41 and 16.21 g/L of 6-DLS production from initial l -fucose concentration of 30, 70 and 100 g/L, which equates to conversion yield of 16.44 %, 16.30 % and 16.21 % respectively. Generally, this study offers a promising strategy for the biological production of 6-DLS from an inexpensive substrate l -fucose in slightly acidic conditions with the aid of co-expression system harboring Pr-LFI and CF-DTE genes.
研究领域:
生物技术
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酶学
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生化工程
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食品科学
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产品关联
DOI
PubMed
高影响因子
Biomass Conversion and Biorefinery
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2019
·Vol. 10
·期 2
·277-287
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IF 2.326
Shi Ning,Liu Qiying,Cen Hu,Ju Rongmei,He Xiong,Ma Longlong
Humins are undesired solids formed during the hydrothermal degradation of carbohydrates. In order to reveal the mechanism of formation of humins, we studied the degradation behavior of 11 model compounds including carbohydrates and furfural derivatives, within water and various pure organic solvents as reaction media. All the studied carbohydrates could generate solid humins in both water and studied organic solvents except ethanol, while the furfural derivatives could generate solid humins in only water. The results could be explained by regarding the formed α-carbonyl aldehydes and α,β-unsaturated aldehydes as primary precursors for formation of humins. Furfural derivatives could generate chain α-carbonyl aldehydes (for example, 6-hydroxy-2,5-dioxohexanal from 5-hydroxymethylfurfural and 2-oxopentanedial from furfural) through hydrolytic ring opening reaction; thus, water is essential for these furfural derivatives to generate humins. As for carbohydrates, they could generate α-carbonyl aldehydes and α,β-unsaturated aldehydes through simple step of β-elimination in all solvents; thus, they could form humins in both water and studied organic solvents except ethanol. Ethanol could react with α-carbonyl aldehydes by acetalization; thus, the condensation between α-carbonyl aldehydes was suppressed in ethanol, leading to few humins formation from carbohydrates. Based on the above analysis, we proposed that the formed α-carbonyl aldehydes and α,β-unsaturated aldehydes should be the primary precursor of humins.
研究领域:
生物化学
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能源化学
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DOI
高影响因子
ACS Sustainable Chemistry & Engineering
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2020
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IF 7.632
Xia Hua,GenLai Du,Jian Han,Yong Xu
A basic scheme of using 2,4-dinitrophenol (2,4-DNP) as an uncoupler between electron transport chain and oxidative phosphorylation for the biochemical regulation of Gluconobacter oxydans (G. oxydans) is raised. Under the weakly acidic environment, the lipophilic 2,4-DNP as an uncoupling agent destroys the electrochemical proton (H+) gradient in mitochondria, which leads to a loss of the driving force for adenosine triphosphate (ATP) synthesis. Based on the main enzyme system of G. oxydans, four typical substrates were studied for exploring the biochemical effects of uncoupling on the cells. As a result, it was found that under uncoupling conditions, cells receive a feedback signal of ATP deficiency, which promotes the utilization of catabolized substrates such as sorbitol and glucose through the substrate level phosphorylation pathway in order to make up for the deficiency of ATP. The proposal of strategy has a further understanding of the basic biochemical knowledge of G. oxydans and lays a theoretical foundation for the directional regulation of G. oxydans.
研究领域:
生化工程
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微生物生物技术
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代谢工程
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产品关联
DOI
高影响因子
FOOD CHEMISTRY
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2017
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IF 4.529
Yao Huang,Fang Feng,Zhi-Gang Chen,Tao Wu,Zi-Han Wang
Natural deep eutectic solvents (NADESs) constitute a novel class of biodegradable and inexpensive solvents. In this study, twenty choline chloride- and glycerol-based NADESs were prepared and investigated as washing agents in the removal of cadmium (Cd) from rice flour for the first time. Choline chloride-based NADESs demonstrated good Cd removal (51%–96%). A natural, biodegradable surfactant, saponin, was mixed with the NADESs to enhance their efficiency. No increase in Cd removal was observed when glycerol-based NADESs were combined with 1% saponin; however, synergistic effects between saponin and choline chloride-based NADESs were observed during the washing process and >99% Cd was removed using NADES-saponin mixtures. Moreover, NADESs washing process did not affect the main chemical components or structure of rice flour. The mechanism of Cd removal by NADESs and regeneration of Cd-contaminated NADESs were also explored. The study presents a green and efficient way of removing Cd from contaminated rice.
研究领域:
环境科学
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食品科学
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化学
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毒理学
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产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）