Systems Microbiology and Biomanufacturing
·
2023
·
IF 0
Sun Tingting,Liu Di,Zhang Linmeng,Fan Taiping,Cai Yujie
(2R,3R)-BDO is an important bio-based four-carbon platform compound and widely used in chemical, food, pharmaceutical, fuel and aerospace fields . Serratia marcescens has been shown to be an effective strain for producing BDO. However, there have been few reports on the metabolic engineering of this strain to efficiently produce (2R,3R)-BDO using xylose. In this study, the endogenous strong promoter was screened and modified, and combined with the screened RBS. (2R,3R)-BDO was successfully produced by combining the selected promoters and RBS with the overexpressed key enzymes (ALS, ALSD, BDH, GLF) of (2R,3R)-BDO production. The optimum fermentation temperature and pH were 37 ℃ and 6.0, respectively, and the optimized yield reached 6.0 g/L. After batch fermentation, the (2R,3R)-BDO yield reached 36.6 g/L. This provided a good idea for efficient production of (2R,3R)-BDO from xylose.
研究领域:
生物工程
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微生物学
·
生物化学
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DOI
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
·
2023
·Vol. 24
·期 18
·14220
·
IF 5.6
Yaping Xu,Zhengwen Li,Yue Wang,Chujie Li,Ming Zhang,Haiming Chen,Wenxue Chen,Qiuping Zhong,Jianfei Pei,Weijun Chen,Guido R. M. M. Haenen,Mohamed Moalin
It has been reported that in an oxidative environment, the flavonoid2R,3R-dihydroquercetin (2R,3R-DHQ) oxidizes into a product that rearranges to form quercetin. As quercetin is a very potent antioxidant, much better than2R,3R-DHQ, this would be an intriguing form of targeting the antioxidant quercetin. The aim of the present study is to further elaborate on this targeting. We can confirm the previous observation that2R,3R-DHQ is oxidized by horseradish peroxidase (HRP), with H2O2as the oxidant. However, HPLC analysis revealed that no quercetin was formed, but instead an unstable oxidation product. The inclusion of glutathione (GSH) during the oxidation process resulted in the formation of a2R,3R-DHQ-GSH adduct, as was identified using HPLC with IT-TOF/MS detection. GSH adducts appeared on the B-ring of the2R,3R-DHQ quinone, indicating that during oxidation, the B-ring is oxidized from a catechol to form a quinone group. Ascorbate could reduce the quinone back to2R,3R-DHQ. No2S,3R-DHQ was detected after the reduction by ascorbate, indicating that a possible epimerization of2R,3R-DHQ quinone to2S,3R-DHQ quinone does not occur. The fact that no epimerization of the oxidized product of2R,3R-DHQ is observed, and that GSH adducts the oxidized product of2R,3R-DHQ on the B-ring, led us to conclude that the redox-modulating activity of2R,3R-DHQ quinone resides in its B-ring. This could be confirmed by chemical calculation. Apparently, the administration of2R,3R-DHQ in an oxidative environment does not result in ‘biotargeting’ quercetin.Keywords:2R,3R-dihydroquercetin;redox modulation;quercetin;quinone;epimerization
研究领域:
生物化学
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药理学
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产品关联
DOI
PubMed
高影响因子
ORGANIC & BIOMOLECULAR CHEMISTRY
·
2022
·Vol. 20
·期 14
·2909-2921
·
IF 3.89
Haidi Yang,Jinyao Liu,Pan Hu,Liang Gao,Zedu Huang,Fener Chen
A new and highly stereoselective synthesis of chiral diol (S)-14, the common synthetic intermediate to (+)-(2R,4′R,8′R)-α-tocopherol (1), was accomplished in seven steps with 13.8% overall yield. This developed route featured a lipase-catalyzed desymmetric hydrolysis of prochiral diester 39a, which was prepared through a challenging Heck coupling, to chiral quaternary carbon-containing monoester (R)-37a of the correct configuration in 81% yield and 96.7% ee, to the best of our knowledge, leading to the most efficient enzymatic desymmetric synthesis of the chiral chroman skeleton of vitamin E members reported to date. Coupled with the modified preparation of the phytol-derived side chain, the chemoenzymatic total synthesis of 1 was completed in 15 longest linear steps with 3.1% overall yield.
研究领域:
有机化学
·
合成化学
·
酶学
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DOI
PubMed
高影响因子
Biochar
·
2022
·Vol. 4
·期 1
·1-13
·
IF 11.452
Hua Li,Cheng Taozhi,Liang Zhiyong,Wei Ting
The mechanism of oxidation and degradation effect of phytate-modified biochar catalyzed persulfate on Ponceau 2R was investigated. Chemical-structural properties of phytate-modified biochar, such as surface morphology and surface oxygen-containing functional groups were characterized. The results suggest that modified biochar has better oxidation performance than unmodified biochar, and the modified biochar generated at 500 ℃ pyrolysis temperature can catalyze peroxymonosulfate (PMS) system with high efficiency, in large pH and temperature scope. And the degradation mechanism of Ponceau 2R by biochar-catalyzed PMS generation (BC-PMS) system was researched. It revealed that PBC300 (phytate-modified biochar pyrolyzed at 300 °C), PBC500 (phytate-modified biochar pyrolyzed at 500 °C), and PBC700 (phytate-modified biochar pyrolyzed at 700 °C) may have metaphosphoric acid linked to oxygen atoms and metaphosphoric acid linked in a bridging manner on the surface of biochar, catalyzing the production of hydroxyl radicals by PMS. PBC700 catalyzes the production of singlet oxygen by PMS through its structural defects, and singlet oxygen is the main catalytic product of PBC700.
研究领域:
环境科学
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化学工程
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材料科学
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产品关联
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2025
·
IF 5.6
Youchi Chen,Shuzhou Xing,Jie Jiang,Ruopeng Li,Yaqiang Li,Xin Li,Mingjie Li,Maozhong An,Jinqiu Zhang,Jiang Qin,Peixia Yang
With the rapid development of 5G communication, artificial intelligence, and new energy vehicles, the metallization of through-holes (THs) in printed circuit boards (PCBs) has imposed stringent requirements on the uniformity and interconnection reliability of copper layers. In this study, a novel azo-based additive Chromotrope 2R (BSS2R) was developed, and combined with pulse electroplating to synergistically regulate the conformal filling of PCB THs and the microstructure of copper. Electrochemical tests showed that BSS2R could reduce cathodic polarization and accelerate Cu²⁺ reduction. Surface and crystallographic characterization confirmed that BSS2R could induce the formation of Cu(111) preferred orientation in the copper layer and increase grain size, and its concentration should be controlled within 20 mg/L to suppress the high-frequency skin effect. Density functional theory (DFT) calculations revealed that the sulfonic acid groups of BSS2R could form strong ionic coordination with Cu²⁺ and preferentially adsorb on Cu(111) crystal planes, driving the oriented growth of copper crystal planes. Pulse electroplating experiments verified the "adsorption pumping effect" of BSS2R, which could increase the throwing power (TP) of THs from 72.5% to 84.1%. This work provides theoretical support and practical technical solutions for the metallization of high-aspect-ratio THs in advanced PCB manufacturing.
研究领域:
材料科学
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电化学
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微电子制造
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表面工程
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凝聚态物理
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产品关联
DOI
高影响因子
Russian Journal of Physical Chemistry A
·
2019
·Vol. 93
·期 4
·696-702
·
IF 0.581
Huanxin Li,Zhang Haihan,Dou Yonghui,Xu Li,Liu Guoji
Abstract The solubility of (1R,2R)-(+)-1,2-diaminocyclohexane L-tartrate (DHT) in methanol + water, ethanol + water, and 2-propanol + water mixed solvents were measured using a synthetic method with alcohols mass fractions varying from 0.1 to 0.5 over 278.15 to 318.15 K under atmospheric pressure ( P = 0.1 MPa). It was proved that the solubility of DHT in the three binary solvents increased with increasing temperature, while decreased with the mass fraction of alcohols rising. The experimental solubility data were correlated by the modified Apelblat equation and Sun model. The modified Apelblat model showed better agreement with the experimental data than the other model. Furthermore, the thermodynamic parameters including \(\Delta G_{{{\text{sol}}}}^{^\circ }\) , \(\Delta H_{{{\text{sol}}}}^{^\circ }\) , and \(\Delta S_{{{\text{sol}}}}^{^\circ }\) for DHT in the dissolution process were obtained from Van’t Hoff plots.
研究领域:
物理化学
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药物化学
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DOI
高影响因子
Foodborne Pathogens and Disease
·
2023
·Vol. 20
·期 3
·90-99
·
IF 2.8
Wenyi Ran,Yuxi Yue,Feiwu Long,Kai Zhong,Jinrong Bai,Yue Xiao,Qian Bu,Yina Huang,Yanping Wu,Hong Gao
Staphylococcus aureus is a major foodborne pathogen that leads to various diseases due to its biofilm and virulence factors. This study aimed to investigate the inhibitory effect of 2R,3R-dihydromyricetin (DMY), a natural flavonoid compound, on the biofilm formation and virulence of S. aureus, and to explore the mode of action using transcriptomic and proteomic analyses. Microscopic observation revealed that DMY could remarkably inhibit the biofilm formation by S. aureus, leading to a collapse on the biofilm architecture and a decrease in viability of biofilm cell. Moreover, the hemolytic activity of S. aureus was reduced to 32.7% after treatment with subinhibitory concentration of DMY (p < 0.01). Bioinformation analysis based on RNA-sequencing and proteomic profiling revealed that DMY induced 262 differentially expressed genes and 669 differentially expressed proteins (p < 0.05). Many downregulated genes and proteins related to surface proteins were involved in biofilm formation, including clumping factor A (ClfA), iron-regulated surface determinants (IsdA, IsdB, and IsdC), fibrinogen-binding proteins (FnbA, FnbB), and serine protease. Meanwhile, DMY regulated a wide range of genes and proteins enriched in bacterial pathogenesis, cell envelope, amino acid metabolism, purine and pyrimidine metabolism, and pyruvate metabolism. These findings suggest that DMY targets S. aureus through multifarious mechanisms, and especially prompt that interference of surface proteins in cell envelope would lead to attenuation of biofilm and virulence.
研究领域:
微生物学
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分子生物学
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药理学
·
致病细菌
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产品关联
DOI
PubMed
高影响因子
FOOD CHEMISTRY
·
2023
·
IF 8.8
Haolin Zhang,Shiye Lin,Ruiwei Xie,Weizhi Zhong,Hui Wang,Mohamed A. Farag,Hidayat Hussain,Randolph R.J. Arroo,Xiaojia Chen,Jianbo Xiao
In the field of thermal degradation of flavonoids, current studies mainly focused on flavonols. However, the thermal degradation of dihydroflavonols in aqueous solution has received limited attention compared to flavonols. The single C2-C3 bonds of dihydroflavonols, which differs from the C2-C3 double bond in flavonols, may cause different degradation mechanisms. Dihydromyricetin (DMY) is a typical dihydroflavonol with six hydroxyl groups, and possesses various health effects. We explored the thermal degradation of DMY in neutral aqueous solution (pH 7) at 100 ℃. Ultra-performance liquid chromatography combined with photodiode array and electrospray ionization quadrupole-time-of-flight tandem mass spectrometric detection (UPLC-PDA-ESI-QTOF–MS/MS) provided suitable platform for exploring DMY degradation pathways, and negative ion mode was applied. Thermal treatment led to a decline in DMY level with time, accompanied by the appearance of various degradation products of DMY. Degradation mechanisms of DMY included isomerization, oxidation, hydroxylation, dimerization and ring cleavage. The pyrogallol-type ring B of DMY might be initially oxidized into ortho -quinone, which could further attack another DMY to form dimers. In addition, hydroxylation is likely to occur at C-2, C-3 of DMY or DMY dimers, which then further yields ring-cleavage products via breakage of the O1-C2 bond, C2-C3 bond, or C3-C4 bond. The 3-hydroxy-5-(3,3,5,7-tetrahydroxy-4-oxochroman-2-yl) cyclohexa-3,5-diene-1, 2-dione ( m / z 333.0244) and unknown compound m / z 435.0925 were annotated as key intermediates in DMY degradation. Four phenolic acids, including 3,4,5-trihydroxybenzoic acid ( m / z 169.0136, RT 1.4 min), 2,4,6-trihydroxyphenylglyoxylic acid ( m / z 197.0084, RT 1.7 min), 2-oxo-2-(2,4,6-trihydroxyphenyl) acetaldehyde ( m / z 181.0132, RT 2.4 min), and 2,4,6-trihydroxybenzoic acid ( m / z 169.0139, RT 2.5 min) were identified as the major end products of DMY degradation. In addition, 5-((3,5dihydroxyphenoxy) methyl)-3-hydroxycyclohexa-3,5-diene-1,2-dione (m / z 261.0399, RT 11.7 min) and unidentified compound with m / z 329.0507 (RT 1.0 min) were also suggested to be end products of DMY degradation. These results provide novel insights on DMY stability and degradation products. Moreover, the heat treatment of DMY aqueous solution was found to gradually reduce the antioxidant activities of DMY, and even destroy the beneficial effect of DMY on the gut microbiota composition.
研究领域:
药学化学
·
分析化学
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食品科学
·
药理学
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产品关联
DOI
PubMed
高影响因子
Biocatalysis and Agricultural Biotechnology
·
2019
·
IF 0
Feng-Qin Gong,Qi-Shun Liu,Hai-Dong Tan,Tang Li,Cheng-Yu Tan,Heng Yin
Acetoin (3-hydroxy-2-butanone) is an important four-carbon compound widely used in the food industry and other industrial applications. This study aimed to identify a novel butanediol dehydrogenase that can efficiently catalyze the formation of acetoin. A novel butanediol dehydrogenase, Bt BDH, was identified from Bacillus thuringiensis subsp. Kurstaki ACCC 10066, and its enzymatic properties were characterized. The optimum pH and temperature for the oxidation activity of Bt BDH were 10.0 and 50 °C, respectively, and those for the reduction activities were 7.5 and 35 °C, respectively. In addition, it exhibits stability over a wide pH range (6–10) and temperatures up to 70 °C. Bt BDH showed good stability after storage for 3 months at 4 °C. Moreover, ethylenediaminetetracetic acid (EDTA) inhibits the enzymatic activity of Bt BDH, indicating that the enzyme is metal-dependent. This study characterized a novel (2R,3R) −2,3-butanediol dehydrogenase. Its excellent oxidation activity and stability ensure its great industrial application potential in the production of acetoin.
研究领域:
生物化学
·
微生物学
·
酶学
✓ 已验证
产品关联
DOI
MOLECULAR BIOTECHNOLOGY
·
2021
·Vol. 63
·期 6
·491-501
·
IF 2.695
Tang Wanggang,Lian Chaoqun,Si Yu,Chang Jianrong
2,3-Butanediol dehydrogenase (BDH), also known as acetoin/diacetyl reductase, is a pivotal enzyme for the formation of 2,3-butanediol (2,3-BD), a chiral compound with potential roles in the virulence of certain pathogens. Here, a NAD(H)-dependent (2 R ,3 R )-BDH from Neisseria gonorrhoeae FA1090 (NgBDH), the causative agent of gonorrhoea, was functionally characterized. Sequence analysis indicated that it belongs to zinc-containing medium-chain dehydrogenase/reductase family. The recombinant NgBDH migrated as a single band with a size of around 45 kDa on SDS-PAGE and could be confirmed by Western blotting and mass spectrometry. For the oxidation of either (2 R ,3 R )-2,3-BD or meso -2,3-BD, the enzyme exhibited a broad pH optimum between pH 9.5 to 11.5. For the reduction of (3 R /3 S )-acetoin, the pH optimum was around 6.5. The enzyme could catalyze the stereospecific oxidation of (2 R ,3 R )-2,3-BD ( K m = 0.16 mM, k cat / K m = 673 s −1 · mM −1 ) and meso -BD ( K m = 0.72 mM, k cat / K m = 165 s −1 · mM −1 ). Moreover, it could also reduce (3 R /3 S )-acetoin with a K m of 0.14 mM and a k cat / K m of 885 s −1 · mM −1 . The results presented here contribute to understand the 2,3-BD metabolism in N. gonorrhoeae and pave the way for studying the influence of 2,3-BD metabolism on the virulence of this pathogen in the future.
研究领域:
微生物学
·
生物化学
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DOI
PubMed
高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2014
·
IF 2.045
Yongzhao Zhang,Xia Guo,Jianbing Ji
(2R,3S,4S,5S)-6-(Hydroxymethyl)-tetrahydro-2H-pyran-2,3,4,5-tetraol (d-glucose) solubility in 1-dodecanol, 1-decanol, and 1-octanol from 343.15 K to 393.15 K was determined, respectively. The solubility of d-glucose increased with an increase in temperature and decreased with the increase of fatty alcohol chain length. The modified UNIQUAC model, S-UNIFAC model, and mS-UNIFAC model were applied to predict the solubility data; the interaction parameters were determined. Of the three models, the modified UNIQUAC model showed better prediction accuracy.
研究领域:
化学工程
·
生物化学
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产品关联
DOI
高影响因子
JOURNAL OF MOLECULAR STRUCTURE
·
2019
·
IF 2.12
Qiang Fu,Hai-Dong Lu,Yi-Fei Xie,Jia-You Liu,Yang Han,Ning-Bo Gong,Fang Guo
Indomethacin ( Indo ) and naproxen ( Nap ) belong to Biopharmaceutical Classification System (BCS) class II drugs, which permeate membranes well but are poorly soluble. Two pharmaceutical salts hydrate of Indo and Nap with (1R,2R)-1,2-diphenylethylenediamine ( DPEN ) were obtained using solution crystallization. Both salts, (DPEN) 2 ·(Indo) 2 ·(H 2 O) 2 and (DPEN) 1 ·(Nap) 1 ·(H 2 O) 0.5 , were characterised using various solid-state characterisation techniques such as single crystal X-ray diffraction (SCXRD), powder X-ray diffraction (PXRD), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and Raman spectra . The structure analysis shows that DPEN is monocation as only one amine is protonated into ammonium. The Indo , DPEN and water molecules form one-dimensional hydrogen bond chains through extensive N H⋯O, N H⋯N and O H⋯N interactions. The solubility study shows that the two salts are more soluble in pH 1.2, 4.5 and 6.8 buffer mediums compared with pure raw materials. Solubility thermodynamics calculation was carried out to further understand the solubility properties of two salts.
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DOI
高影响因子
危险品化学品经营许可证（带存储）