JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2017
·
IF 2.323
Tiantian Ye,Haibin Qu,Xingchu Gong
The liquid–liquid equilibrium (LLE) data of ternary systems of water + d-fructose + 1-butanol, water + d-glucose + 1-butanol, and water + d-galactose + 1-butanol were determined at three temperatures (288.2, 303.2, and 318.2 K) and atmospheric condition. The distribution coefficients of the monosaccharides were lower than 0.05. For all the three saccharides, their content in the organic-rich phase increased as their content in the aqueous phase increased. The experimental tie-line data were fitted using the Othmer–Tobias equation. The saccharide universal quasichemical functional-group activity coefficient (S-UNIFAC) model was used to predict the LLE data with all the average absolute deviations (AAD) values higher than 0.013. The modified universal quasichemical model was then used to correlate the LLE data. The correlation results agreed better with experimental data than the prediction results obtained with S-UNIFAC. In the production of traditional Chinese medicines, 1-butanol is a promising extractant used to separate active compounds and saccharides in aqueous herbal extracts.
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JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
·
2026
·Vol. 74
·期 29
·22965-22974
·
IF 6.7
Li Mengyu,Fu Chenchen,Zhuang Wei,Zhang Keke,Xu Jingliang,Wang Zhenfu
D-Amino acid oxidase (DAAO) catalyzes the oxidation of
D-phosphinothricin
(D-PPT) to produce optically pure L-PPT, but low catalytic efficiency
limits its industrial application. Here, a synergistic strategy combining
geometric remodeling and charge engineering was applied to enhance
the oxidation activity of our previously developed stable variant
TIF-DAAO (S18T/V7I/Y132F) toward D-PPT. Systematic analysis of the
active pocket-guided alanine and neutral hydrophilic (Ser/Thr/Tyr)
scanning mutagenesis revealed position-specific steric constraints.
Subsequent Arg/His scanning tailored the positively charged microenvironment
around D-PPT, leading to a triple mutant ATR (F58A/Q335T/P221R) with
improved electrostatic complementarity and spatial fit. ATR showed
a 10.7-fold increase in catalytic activity, a 35-fold improvement
in substrate affinity, and a 380-fold higher catalytic efficiency
( k cat / K M )
toward D-PPT. Molecular dynamics simulations provided mechanistic
insight. Our results demonstrate that the synergistic optimization
of substrate tunnel geometry and the electrostatic microenvironment
effectively boosts DAAO activity, offering a rational strategy for
engineering industrial biocatalysts.
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AMB Express
·
2019
·Vol. 9
·期 1
·1-11
·
IF 2.226
Guo Zongren,Long Liangkun,Ding Shaojun
d -Mannose and l -ribose are two important monosaccharides, which have attracted public attention recently because of their great application potentials in food, cosmetic and pharmaceutical industries. Sugar isomerases catalyze the sugar isomerization and therefore can be used as the biocatalysts for production of the high-value sugars from inexpensive sugars. l -arabinose isomerase catalyzes the conversion of l -arabinose to l -ribulose, while d -lyxose isomerase catalyzes l -ribulose and d -fructose to l -ribose and d -mannose, respectively. In this paper, a putative d -LI from Bacillus velezensis (BvLI) was identified, characterized and used to produce d -mannose and l -ribose from d -fructose and l -arabinose, respectively. The recombinant BvLI exhibited a maximum activity at 55 °C and pH 6.5, in the presence of 0.1 mM Co 2+ . Approximately 110.75 g/L d -mannose was obtained from 500 g/L d -fructose in 6 h by the recombinant BvLI, and approximately 105 g/L l -ribose was obtained from 500 g/L l -arabinose in 8 h by the successive biocatalysis of l -arabinose isomerase from Bacillus licheniformis (BlAI) and BvLI.
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ANALYTICAL BIOCHEMISTRY
·
2015
·
IF 2.219
Fang Wang,Wencheng Gong,Lili Wang,Zilin Chen
Selective recognition of d -tryptophan ( d -Trp) in the presence of Cu(II) was investigated at poly- l -lysine (p-l-Lys) film using electrochemical impedance spectroscopy (EIS) and differential pulse voltammetry (DPV). p-l-Lys film was immobilized on a glassy carbon electrode (GCE) by cyclic voltammetry between 0.0 and 1.9 V in 20 mM phosphate buffer solution (pH 8.6). After the p-l-Lys/GCE electrode was incubated with d -Trp solution containing Cu(II) ions, obvious enhancement of electron transfer resistance and decrease of voltammetric current could be observed. If d -Trp was replaced by l -tryptophan (l-Trp), there was no apparent resistance and current changes. Moreover, no resistance and current changes could be found in the absence of Cu(II). It may be due to the formation of Cu complex with l -lysine and d -tryptophan. Finally, this method was successfully applied to monitoring enantiomeric composition of the d -Trp and l-Trp mixtures.
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INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2024
·
IF 7.7
Huayang Tang,Yian Chen,Dexun Fan,Fengguang Zhao,Shuangyan Han
D-allulose, a low-calorie rare sugar catalyzed by D-allulose 3-epimerase (DAE), is highly sought after for its potential health benefits. However, poor reusability and stability of DAE limited its popularization in industrial applications. Although metal-organic frameworks (MOFs) offer a promising enzyme platform for enzyme immobilization, developing customized strategies for MOF immobilization of enzymes remains challenging. In this study, we introduce a designable strategy involving the construction of bimetal-organic frameworks (ZnCo-MOF) based on metal ions compatibility. The DAE@MOFs materials were prepared and characterized, and the immobilization of DAE and the enzymatic characteristics of the MOF-immobilized DAE were subsequently evaluated. Remarkably, DAE@ZnCo-MOF exhibited superior recyclability which could maintain 95 % relative activity after 8 consecutive cycles. The storage stability is significantly improved compared to the free form, with a relative activity of 116 % remaining after 30 days. Molecular docking was also employed to investigate the interaction between DAE and the components of MOFs synthesis. The results demonstrate that the DAE@ZnCo-MOF exhibited enhanced catalytic efficiency and increased stability. This study introduces a viable and adaptable MOF-based immobilization strategy for enzymes, which holds the potential to expand the implementation of enzyme biocatalysts in a multitude of disciplines.
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BIOTECHNOLOGY AND BIOENGINEERING
·
2024
·
IF 3.5
Feng Cheng,Ke-Xiang Sun,Xiao-Xiao Gong,Wei Peng,Hua-Yue Zhang,Xi-Hang Liang,Ya-Ping Xue,Yu-Guo Zheng
D-amino acid oxidase (DAAO)-catalyzed selective oxidative deamination is a very promising process for synthesizing l -amino acids including l -phosphinothricin ( l -PPT, a high-efficiency and broad-spectrum herbicide). However, the wild-type DAAO's low activity toward unnatural substrates like d -phosphinothricin ( d -PPT) hampers its application. Herein, a DAAO from Caenorhabditis elegans ( Ce DAAO) was screened and engineered to improve the catalytic potential on d -PPT. First, we designed a novel growth selection system, taking into account the intricate relationship between the growth of Escherichia coli ( E. coli ) and the catalytic mechanism of DAAO. The developed system was used for high-throughput screening of gene libraries, resulting in the discovery of a variant (M6) with significantly increased catalytic activity against d -PPT. The variant displays different catalytic properties on substrates with varying hydrophobicity and hydrophilicity. Analysis using Alphafold2 modeling and molecular dynamic simulations showed that the reason for the enhanced activity was the substrate-binding pocket with enlarged size and suitable charge distribution. Further QM/MM calculations revealed that the crucial factor for enhancing activity lies in reducing the initial energy barrier of the reductive half reaction. Finally, a comprehensive binding-model index to predict the enhanced activity of DAAO toward d -PPT, and an enzymatic deracemization approach was developed, enabling the efficient synthesis of l -PPT with remarkable efficiency.
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FOOD CHEMISTRY
·
2020
·
IF 6.306
Yu Xu,Ziyi Liu,Zhaoye Liu,Zhihui Feng,Liang Zhang,Xiaochun Wan,Xiaogen Yang
During manufacturing processes and in the storage period of tea, amino acids may undergo enantiomeric isomerization, converting their l - to d -forms. To examine the hypothesis, a method was developed for the analysis of the enantiomers in tea leaves. After enriched by ion-exchange solid-phase extraction, the enantiomeric pairs were separated by a chiral high performance liquid chromatography (HPLC) and subsequently detected and identified by using a high resolution quadrupole time-of-flight mass spectrometry (QTOF MS). Only l -forms of amino acids were found in fresh tea leaves. A total of 11 d -amino acids were found in 19 tea samples, ranging from trace amount to 43 µg/g. The results indicated that the enantioisomerization of amino acids occurred in post-harvest tea leaves, and affected by process conditions and storage time.
研究领域:
食品科学
·
分析化学
·
农业化学
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JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
·
2022
·
IF 5.895
Fang Fu,Yulin Fan,Langqiu Chen,Jing Zhang,Jiping Li,Jingyi Liao,Guochao Zhang
A series of nonionic disaccharide-based surfactants alkyldi(oxyethylene) β-d-maltosides (4a–4h, n = 6–16) were synthesized, and their physicochemical properties were further investigated. Six β-D-maltosides (4c–4h, n = 8–16) exhibited a fan-shaped texture feature, whereas hexyldi(oxyethylene) β-D-maltoside (4a) had the strongest hygroscopicity. Owing to the incorporation of the hydrophilic dioxyethyl spacer (−(OCH2CH2)2−), the related water solubility improved significantly. Tetradecyldi(oxyethylene) β-D-maltoside (4g) had good water solubility, whereas hexadecyldi(oxyethylene) β-D-maltoside (4h) had weak water solubility. Meanwhile, the surface tension of β-D-maltosides (4a–4g, n = 6–14) had a decreasing tendency with increasing the alkyl chain length, whereas 4g had the best surface activity. Furthermore, decyldi(oxyethylene) β-D-maltoside (4e) had the best foaming ability and foam stability. Dodecyldi(oxyethylene) β-D-maltoside (4f) had the best emulsifying property in the rapeseed oil/water system. In contrast, both ammonium dodecyl sulfate (NH4DS)/4f and cetyltrimethylammonium chloride (CTAC)/4f binary surfactant systems showed a synergistic effect in surface activity because the CCMC/CMCidmix was <1. NaCl impacted the surface activity of the aqueous 4f solution through salt–surfactant synergistic effects. The results showed that such surfactants should have potential applications in the related field in the future.
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JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
·
2020
·
IF 4.192
Yulin Fan,Fang Fu,Langqiu Chen,Jiping Li,Jing Zhang
Dioxyethene fragment (−(OCH2CH2)2−) was introduced into traditional alkyl β-d-glucopyranosides to ameliorate the water solubility, and eight nonionic surfactants, that is, alkoxy ethoxyethyl β-d-glucopyranosides with alkyl chain lengths (n = 6–16), were synthesized and characterized. Their hydrophilic and lipophilic balance number, water solubility, critical micelle concentration (cmc), γcmc, Γmax, and hygroscopic rate decreased with an increase in the alkyl chain length. Hexadecoxy ethoxyethyl β-d-glucopyranoside had no water solubility at 25 °C. Decoxy ethoxyethyl β-d-glucopyranoside had the best emulsifying property in the toluene/water and n-octane/water systems and the strongest foaming property, whereas dodecoxy ethoxyethyl β-d-glucopyranoside had the best emulsifying property in the rapeseed oil/water system. Such β-d-glucopyranosides (n = 6–12) exhibited excellent surface activity. In addition, for the binary mixture of alkoxy ethoxyethyl β-d-glucopyranosides (n = 8, 10, 12) and sodium dodecyl sulfate or cetyl trimethyl ammonium chloride, their cmc values were lower than the pure β-d-glucopyranosides, indicating that they had synergistic interactions. The fan focal conic textures of alkoxy ethoxyethyl β-d-glucopyranosides (n = 7–16) were observed during the cooling process under a polarizing optical microscope. Alkoxy ethoxyethyl β-d-glucopyranosides (n = 14, 16) had the related melting points and the clear points with differential scanning calorimetry. With β-d-glucopyranosides (n = 6–16) and n-butanol as the surfactant and cosurfactant, respectively, and with cyclohexane as the oil phase, the related microemulsion areas in their pseudoternary phase diagram system were investigated with the visual observation at 25 °C. Along with the slashing requirements of petroleum consumption, environmental protection, and green and sustainable development, nonionic sugar-based alkoxy ethoxyethyl β-d-glucopyranosides should be expected to have their potential practical application because of their strengthened hydrophilicity, improved water solubility, and enhanced surface activity.
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MOLECULES
·
2018
·Vol. 23
·期 5
·1185
·
IF 3.098
Huiping Chen,Xuewen Li,Yongli Xu,Kakei Lo,Huizhen Zheng,Haiyan Hu,Jun Wang,Yongcheng Lin
The polar extract of theDendrobiumspecies orF. fimbriata(a substitute ofDendrobium), between the fat-soluble extract and polysaccharide has barely been researched. This report worked on the qualitative and quantitative studies of polar extracts fromD. nobile,D. officinale,D. loddigesii, andF. fimbriata. Eight water-soluble metabolites containing a new diglucoside, flifimdioside A (1), and a rare imidazolium-type alkaloid, anosmine (4), were identified using chromatography as well as spectroscopic techniques. Their contents in the four herbs were high, approximately 0.9–3.7 mg/g based on the analysis of quantitative nuclear magnetic resonance (qNMR) spectroscopy. Biological activity evaluation showed that the polar extract ofF. fimbriataor its pure component had good antioxidant and neuroprotective activity; compounds1‒4and shihunine (8) showed weak α-glucosidase inhibitory activity;4and8had weak anti-inflammatory activity. Under trial conditions, all samples had no cytotoxic activity.Keywords:Dendrobium;Flickingeria fimbriata;qNMR;α-glucosidase inhibition;antioxygenation;neuroprotection
研究领域:
植物化学
·
药理学
·
代谢组学
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BIORESOURCE TECHNOLOGY
·
2022
·
IF 11.889
Guoyan Zhang,Hossain M. Zabed,Yingfeng An,Junhua Yun,Jiaqi Huang,Yufei Zhang,Xiaolan Li,Jiangfei Wang,Yuvaraj Ravikumar,Xianghui Qi
Dairy industry waste has been explored as a cheap and attractive raw material to produce various commercially important rare sugars. In this study, a lactose-rich dairy byproduct, namely cheese whey powder (CWP), was microbially converted into three low caloric sweeteners using whole-cell and fermentation technologies. Firstly, the simultaneous lactose hydrolysis and isomerization of lactose-derived D-galactose into D-tagatose was performed by an engineered Escherichia coli strain co-expressing β-galactosidase and L-arabinose isomerase, which eventually produced 68.35 g/L D-tagatose during sequential feeding of CWP. Subsequently, the mixed syrup containing lactose-derived D-glucose and residual D-galactose was subjected to fermentation by Metschnikowia pulcherrima E1, which produced 60.12 g/L D-arabitol and 28.26 g/L galactitol. The net titer of the three rare sugars was 156.73 g/L from 300 g/L lactose (equivalent to 428.57 g/L CWP), which was equivalent to 1.12 mol product/mol lactose and 52.24% conversion efficiency in terms of lactose.
研究领域:
生物技术
·
食品科学
·
微生物学
·
生物化学工程
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Molecular Catalysis
·
2026
·
IF 4.3
Jiarong Zhang,Christian Marcus Pedersen,Shuwei Chen,Yingxiong Wang,Yan Qiao
A green epimerization system using only water and CaCl 2 . • NMR identifies products, by-products, and reveals the mechanism. • Isotope labeling and DFT confirm the epimerization pathway. • A direct route to ManNAc from a biomass monomer. N -acetyl- d -mannosamine (ManNAc) is a valuable precursor in the pharmaceutical and biotechnology industries. Enzymatic epimerization of N -acetyl- d -glucosamine (GlcNAc) offers mild and green conditions for ManNAc production, while its productivity is limited by poor enzyme stability and high costs. Although efficient chemical methods have been developed, they often require strict control of reaction conditions to avoid by-product formation, and their reaction mechanisms remain unclear. This study presents a green and efficient strategy for ManNAc synthesis through calcium chloride (CaCl 2 )-promoted epimerization of GlcNAc in aqueous solution. ManNAc production reached a yield of 27% under optimized conditions. The reaction mechanism was elucidated through a combination of nuclear magnetic resonance (NMR) spectroscopy and density functional theory (DFT) calculations. Using deuterium oxide (D 2 O) as the reaction medium revealed hydrogen-deuterium exchange at the C2 position of GlcNAc, providing direct experimental evidence for a reaction pathway involving an enol intermediate. This finding was further supported by subsequent 13 C isotopic labeling experiments. DFT calculations further revealed that water molecules play a critical role in mediating proton transfers, significantly reducing the energy barriers of the key steps of enol intermediate formation. CaCl 2 enhanced the yield by promoting the formation of the enol intermediate. Additionally, a preliminary investigation was conducted on the purification of ManNAc from the reaction mixture containing its structural epimers. This work not only provides a green system for ManNAc synthesis but also offers profound insights into the reaction mechanism, paving the way for developing more efficient biomass utilization strategies. Download: Download high-res image (515KB) Download: Download full-size image
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危险品化学品经营许可证（带存储）