DALTON TRANSACTIONS
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2026
·
IF 3.3
Cai-Ming Liu,Yi-Quan Zhang,Xiang Hao,Xi-Li Li
It is still a major challenge to construct multifunctional complexes using axial chiral ligands. Herein, the axial chiral ligands (R)/(S)-1,1'-binaphthyl-2,2'-diyl hydrogen phosphate (R-HL/S-HL) was used as a bridging ligand, and together with the Schiff base bridging ligand {H2LSchiff = [2-[(E)-(5-fluoro-2-hydroxyphenyl)methylidene]diazanyl](4-chloropyridin-2-yl)methanone}, two pairs of homochiral Dy2 complexes [Dy2(R-L/S-L)2(LSchiff)2(DMA)2]·3DMA·4H2O (R-1/S-1) and [Dy2(R-L/S-L)2(LSchiff)2(DMF)2]·3DMF (R-2/S-2) were successfully constructed at room temperature in different solvents (DMA vs DMF). Interestingly, although their coordination modes as terminal ligands are very similar, the subtle differences between DMA and DMF molecules cause changes in the space groups: R-1 and S-1 crystallize in the P1 chiral space group whereas R-2 and S-2 in the P212121 chiral space group, which may affect their nonlinear optical properties: R-1 and S-1 exhibits both SHG and THG responses, while R-2 and S-2 only displays a THG response. Notably, R-1/S-1 and R-2/S-2 are ferromagnetic coupling, and behave as single-molecule magnets (SMMs) at 0 Oe, and their magnetic properties were further studied using Ab initio calculations. Moreover, the magneto-optical effects of R-1/S-1 and R-2/S-2 were investigated by their magnetic circular dichroism (MCD) spectra.
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高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2026
·
IF 8.7
Bin Yan,Hongru Zhao,Bingmei Su,Juan Lin
Protein engineering altered the reaction direction of TsRTA for AP. • Adjusting the catalytic center and entrance of TsRTA promoted AP binding. • A 10-site variant of TsRTA enabled biosynthesis of ( R )-1-PEA. • An acetone elimination module increased Mu10 productivity by 57.4%. ( R )-1-Phenylethylamine [( R )-1-PEA] is an important chiral compound widely used in pharmaceuticals, chemical synthesis, and materials science. ω-Transaminases are valuable biocatalysts for the asymmetric amination of ketone substrates under mild conditions and represent an attractive tool for the green synthesis of chiral amines. However, in natural ( R )-selective transaminases, acetophenone (AP) is more commonly produced as the deamination product of ( R )-1-PEA, whereas its amination as an amino acceptor is generally inefficient. In this study, an ( R )-selective ω-transaminase from Thermomyces stellatus (TsRTA), which originally catalyzed only the deamination of ( R )-1-PEA to AP, was selected as the engineering target. Protein engineering was performed to shift its reaction equilibrium, thereby enabling the asymmetric synthesis of ( R )-1-PEA from AP. To overcome the thermodynamic limitation caused by acetone accumulation, an “acetone elimination–cofactor regeneration” coupled module was introduced to improve the whole-cell catalytic efficiency for ( R )-1-PEA synthesis using AP as the substrate. Under optimal reaction conditions (35 °C, pH 10.0, 0.5 mM PLP, an isopropylamine/AP molar ratio of 4:1, 200 mM formate, and 0.2 mM NAD + ), the whole-cell catalytic system produced 67 mM ( R )-1-PEA from 100 mM AP within 8 h. This study lays a foundation for the scalable preparation of ( R )-1-PEA and provides a useful reference for regulating the reaction direction of transaminases. Download: Download high-res image (205KB) Download: Download full-size image
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PHARMACEUTICAL BIOLOGY
·
2022
·
IF 3.889
Bo Lu,Jianhua Li,MingTai Gui,Lei Yao,Mingsong Fan,Xunjie Zhou,Deyu Fu
Context Salvianolic acid B (SalB) can attenuate myocardial ischemia/reperfusion (I/R) injury, but the mechanisms are not entirely known.Objective Our study investigates if SalB protects cardiomyocytes against I/R injury by regulating Tripartite motif (TRIM) protein.Materials and methods AC16 cardiomyocytes were treated with I/R, and then with SalB (10, 25 and 50 μM) for 24 h, while control cells were cultured under normal conditions. Female Sprague-Dawley rats were subjected to I/R injury, and then intravenously injected with 20, 40, or 60 mg/kg SalB or saline, as a control, rats received sham operation and saline injection.Results Upon treatment, apoptotic rate, reactive oxygen species (ROS), and malondialdehyde (MDA) were increased 10-, 3.8-, and 1.3-fold, respectively, while superoxide dismutase (SOD) activity was reduced by 62.1% compared to control cells. I/R treatment elevated the mRNA and protein expression of TRIM8. SalB treatment remarkably abolished the above-mentioned effects of I/R treatment. TRIM8 knock-down could partially alleviate I/R-induced myocardial injury. TRIM8 overexpression promoted cardiomyocyte injury, which was alleviated by SalB. Moreover, TRIM8 negatively regulated protein expression of antioxidant enzyme glutathione peroxidase 1 (GPX1). TRIM8 protein interacted with GPX1 and TRIM8 overexpression promoted GPX1 ubiquitnation. GPX1 knock-down abolished the protective effects of SalB on I/R-injured cardiomyocytes. Our in vivo experiments confirmed the effects of SalB on I/R-induced myocardial injury.Discussion and conclusions SalB protected cardiomyocytes from I/R-induced apoptosis and oxidative stress in vitro and in vivo, which was partly mediated by the TRIM8/GPX1 axis. This suggests that down-regulation of TRIM8 expression may ameliorate I/R-induced myocardial injury.
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Antioxidants
·
2022
·Vol. 11
·期 8
·1530
·
IF 7.675
Qingxiu Liu,Wenxiang Li,Shimeng Huang,Lihong Zhao,Jianyun Zhang,Cheng Ji,Qiugang Ma
The development of single enantiomers with high efficiency and low toxic activity has become a hot spot for the development and application of drugs and active additives. The aim of the present study was to investigate the effectiveness of the application of α-lipoic acid with a different optical rotation to alleviate the inflammation response and oxidative stress induced by oxidized fish oil in laying hens. Sixty-four 124-week-old Peking Red laying hens were randomly allocated to four groups with eight replicates of two birds each. The normal group was fed basal diets supplemented with 1% fresh fish oil (FO), and the oxidative stress model group was constructed with diets supplemented with 1% oxidized fish oil (OFO). The two treatment groups were the S-form of the α-lipoic acid model with 1% oxidized fish oil (OFO + S-LA) and the R-form of the α-lipoic acid model with 1% oxidized fish oil (OFO + R-LA) added at 100 mg/kg, respectively. Herein, these results were evaluated by the breeding performance, immunoglobulin, immune response, estrogen secretion, antioxidant factors of the serum and oviduct, and pathological observation of the uterus part of the oviduct. From the results, diets supplemented with oxidized fish oil can be relatively successful in constructing a model of inflammation and oxidative stress. The OFO group significantly increased the levels of the serum inflammatory factor (TNF-α, IL-1β, IL-6, and IFN-γ) and the oxidative factor MDA and decreased the activity of the antioxidant enzyme (T-AOC, T-SOD, GSH-Px, GSH, and CAT) in the oviduct. The addition of both S-LA and R-LA significantly reduced the levels of serum inflammatory factors (TNF-α, IL-1β, IL-6, and IFN-γ), increased the activity of antioxidant indexes (T-AOC, T-SOD, GSH-Px, GSH, and CAT), and decreased the MDA contents in the serum and oviduct. Meanwhile, the supplementation of S-LA and R-LA also mitigated the negative effects of the OFO on the immunoglobulins (IgA and IgM) and serum hormone levels (P and E2). In addition, it was worth noting that the R-LA was significantly more effective than the S-LA in some inflammatory (IL-1β) and antioxidant indices (T-SOD, GSH, and CAT). Above all, both S-LA and R-LA can alleviate the inflammation and oxidative damage caused by oxidative stress in aged laying hens, and R-LA is more effective than S-LA. Thus, these findings will provide basic data for the potential development of α-lipoic acid as a chiral dietary additive for laying hens.Keywords:S-form of α-lipoic acid;R-form of α-lipoic acid;oxidized fish oil;antioxidant;laying hen
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高影响因子
JOURNAL OF BIOMATERIALS APPLICATIONS
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2022
·
IF 2.712
Zao Cheng,Junfei Gao,Qianqian Liu,Qun Gu
This work describes the relationship between the antibacterial activity and the ester chain length (C1-C8) of (R)-3-Hydroxybutyric ((R)-3-HB) alkyl esters that synthesized from (R)-3-HB acid ((R)-3-HBA) by esterification reaction. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) decrease as the length of the (R)-3-HB alkyl ester chain increases from 1 to 6, but (R)-3-HB-C7 and (R)-3-HB-C8 have their own rules for different microorganisms. Among them, the (R)-3HB-C6 has the relatively best antibacterial and antifungal properties, which MIC were 1.95 mg mL−1 against E. coli and S. aureus; 0.98 mg mL−1 against C. albicans and B. subtilis; 0.49 mg mL−1 against A. niger. Finally, the antimicrobial mechanisms of the (R)-3HB-C6 are revealed, and these include disruption of biofilm and the bacterial wall/membrane, leakage of the intracellular content, and change in the transmembrane potential. These results imply the potential application of (R)-3-HB alkyl ester as new antimicrobial agents; future research can use this as an antibacterial element to synthesize new polymer materials or agents with high-efficiency antibacterial activity.
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高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
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2021
·Vol. 32
·期 7
·9032-9043
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IF 2.478
Liu Yunyi,Pan Yongqi,Bai Xudong,Wang Jinchuan,He Caiwang,Xu Zunping,Chen Yi
A conventional ceramic preparation method was used to fabricate the newly designed ternary (K,Na)NbO 3 -based lead-free ceramics, which have the general formula of (0.97- x )K 0.40 Na 0.60 Nb 0.95 Sb 0.05 O 3 –0.03Bi 0.5 K 0.5 HfO 3 – x SrZrO 3 . An X-ray diffraction analysis, together with dielectric-temperature measurements, was performed for determining their phase structures. The crystal structure was found to transition from a rhombohedral-orthogonal phase coexistence to a three-phase coexistence of rhombohedral-orthogonal-tetragonal phases with the increase in SrZrO 3 concentration, and then to a rhombohedral-tetragonal phase coexistence, and finally to a single rhombohedral phase. Near the three-phase coexistence zone, the ceramics exhibit an obviously enhanced electrical activity, with an electromechanical coupling coefficient k p = 0.364 and a piezoelectric constant d 33 = 280 pC/N. Through a microstructure analysis, a slightly excessive amount of SrZrO 3 was found to result in an inhibition for the grain growth of the studied ceramics. These results show that incorporating SrZrO 3 into ternary (K,Na)NbO 3 -based ceramics is still an effective means of constructing phase boundaries and improving the electromechanical properties.
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MICROCIRCULATION
·
2020
·Vol. 28
·期 4
·e12675
·
IF 2.11
Qingbo Shao,Jing Xia,Pinwen Wu,Jiazhou Ying
Background Dexmedetomidine (Dex) exerts an effective therapeutic role in numerous diseases associated with ischemia/reperfusion (I/R) injury via its anti‑apoptosis properties. Therefore, this study explores the cardioprotective effects of Dex in cardiac microvascular endothelial cells (CMECs) in response to oxygen-glucose deprivation and re-oxygenation (OGD/R) injury and its potential mechanism. Material and methods CMECs were pretreatment with different concentration of Dex, then exposed to OGD/R. Cell viability was measured with CCK-8 assay. Apoptosis was evaluated by flow cytometry, and apoptosis-related protein was determined by Western blot. Autophagy was assessed by transmission electron microscopy and autophagy-related proteins. Besides, the role peroxisome proliferator-activated receptors (PPARδ) in Dex-mediated anti-apoptosis property was validated with agonist and antagonist. Results OGD/R significantly decreased cell viability, increased reactive oxygen species, caused disorder of autophagy, and increased apoptosis in CMECs. Dex enhanced the viability of the OGD/R-treated CMECs and effectively decreased reactive oxygen species production. Autophagy in CMECs was activated by Dex, as evidenced by the increase in the ratio of LC3B-II/I, expression level of Beclin1 and number of autophagosomes in the OGD/R-induced CMECs. The mechanistic investigation indicated that PPARδ antagonist GW501516 aggravated cell damage following OGD/R, while PPARδ agonist GW6471 partly abolished the Dex-mediated protective effects. Conclusions Dex activated the PPARδ-AMPK-PGC-1α pathway-mediated autophagy in CMECs, therefore to inhibit excessive apoptosis induced by OGD/R. Dex may potentially be a therapeutic intervention for myocardial I/R injury.
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Catalysts
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2021
·Vol. 11
·期 9
·1126
·
IF 4.146
Qingman Li,Qihua Jiang,Pengcheng Gu,Lianju Ma,Yiwu Wang
Ni2+-NTA-boosted magnetic porous silica nanoparticles (Ni@MSN) to serve as ideal support for bi-functional enzyme were fabricated for the first time. The versatility of this support was validated by one-step purification and immobilization of bi-functional enzyme MLG consisting of 3-Quinuclidinone reductase and glucose dehydrogenase, which can simultaneously catalyze both carbonyl reduction and cofactor regeneration, to fabricate an artificial bi-functional nanobiocatalyst (namely, MLG-Ni@MSN). The enzyme loading of 71.7 mg/g support and 92.7% immobilization efficiency were obtained. Moreover, the immobilized MLG showed wider pH and temperature tolerance and greater storage stability than free MLG under the same conditions. The nanosystem was employed as biocatalyst to accomplish the 3-quinuclidinone (70 g/L) to (R)-3-quinuclidinol biotransformation in 100% conversion yield with >99% selectivity within 6 h and simultaneous cofactor regeneration. Furthermore, the immobilized MLG retained up to 80.3% (carbonyl reduction) and 78.0% (cofactor regeneration) of the initial activity after being recycled eight times. In addition, the MLG-Ni@MSN system exhibited almost no enzyme leaching during biotransformation and recycling. Therefore, we have reason to believe that the Ni@MSN support gave great promise for constructing a new biocatalytic nanosystem with multifunctional enzymes to achieve some other complex bioconversions.Keywords:porous silica nanoparticles;immobilized enzyme;nanosystem;cofactor regeneration;(R)-3-quinuclidinol;biocatalysts’ recycling
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Analytical Methods
·
2014
·Vol. 6
·期 10
·3474-3481
·
IF 1.938
Yuanzhen Zhou,Weimin Tang,Jing Wang,Guo Zhang,Shouning Chai,Liang Zhang,Ting Liu
A sensitive and selective method based on a poly(alizarin yellow R)-modified carbon paste electrode (PAYR/CPE) to detect dopamine (DA) and uric acid (UA) was successfully established. The morphology of the electrode surface was observed by scanning electron microscopy (SEM). Electrochemical characterization of the PAYR/CPE was investigated by electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV) and differential pulse voltammetry (DPV). It was illustrated that the PAYR/CPE had excellent electro-catalytic ability toward the oxidation of DA. The anodic peak current of DA was greatly enhanced at the PAYR/CPE, and the standard rate constant (ks) was calculated to be 6.17 s−1. The linear calibration curves were obtained as 0.49–70.1 μM and 83.6–488.1 μM for DA and 27.8–304.4 μM and 381.6–1118 μM for UA by DPV. The detection limits were 0.16 μM for DA and 9.5 μM for UA. Moreover, the modified electrode was applied to the selective detection of DA and UA with high sensitivity and selectivity. Furthermore, the modified electrode displayed high reproducibility and stability for determination of these species. Thus, the proposed electrode could be conveniently employed for the determination of DA and UA in real samples and provide satisfactory results.
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Journal of Oceanology and Limnology
·
2017
·Vol. 36
·期 2
·473-482
·
IF 0
Gong Yanhui,Ma Sanmei,Wang Yongfei,Xu Yongkai,Sun Aijun,Zhang Yun,Hu Yunfeng
A novel esterase EstC10 from Bacillus sp. CX01 isolated from the deep sea of the Western Pacific Ocean and the functionalities of EstC10 was characterized. At present, the reports about the kinetic resolution of racemic methyl 2-chloropropionate were quite rare. So we developed deep-sea microbial esterase EstC10 as a novel biocatalyst in the kinetic resolution of racemic methyl 2-chloropropionate and generate ( R )-methyl 2-chloropropionate with high enantiomeric excess (>99%) after the optimization of process parameters such as pH, temperature, organic co-solvents, surfactants, substrate concentration and reaction time. Notably, the optimal substrate concentration (80 mmol/L) of esterase EstC10 was higher than the kinetic resolution of another esterase, Est12-7 (50 mmol/L). The novel microbial esterase EstC10 identified from the deep sea was a promising green biocatalyst in the generation of ( R )-methyl 2-chloropropionate as well of many other valuable chiral chemicals in industry.
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Journal of Materials Chemistry C
·
2025
·
IF 5.1
Chang Zhang,Xin Zhang,Wei Wang,Hao Xue,Qian He,Fenglin Li,Xiaoli Wang,Qinghui Jin,Kun Zhou,Jiawen Jian
This paper presents an ammonia (NH3) fluorescent sensor based on the MAPbBr3 perovskite and the multifunctional organic material (R/S)-OBN-tCz. The incorporation of (R/S)-OBN-tCz enhances the sensor's photoluminescence (PL) intensity through Förster resonance energy transfer (FRET) and passivation effects, which consequently improves the sensitivity of the gas sensor. The MAPbBr3&(R/S)-OBN-tCz@PMMA nanofibers fabricated via electrospinning technology not only increase the specific surface area effectively, which is crucial for sensitivity improvement, but also strengthen the stability of the perovskite material under an air atmosphere. The experimental results demonstrate that the sensor maintains stable PL performance for up to 30 days in air and over 10 hours in water, while exhibiting rapid and reversible fluorescence response to NH3.
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INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2025
·
IF 8.5
Xinqi Xu,Fahui Xu,Jingjing Chen,Shumin Wang,Xialian Wang,Bingmei Su,Lian Xu,Juan Lin
Baeyer-Villiger monooxygenases (BVMOs) can catalyze the asymmetric sulfoxidation to form pharmaceutical prazoles in environmentally friendly approach. In this work, the thermostable BVMO named PockeMO had high sulfoxidation activity towards rabeprazole sulfide to form ( R )-rabeprazole but demonstrated significant overoxidation activity to form undesired sulfone by-product. To address this issue, the enzyme was engineered based on the computer assisted comparison for the substrate binding conformations. A mutant S482Y/L532Q (MU2) was obtained with much alleviated overoxidation activity and enhanced sulfoxidation activity towards rabeprazole sulfide. The catalytic efficiency for ( R )-rabeprazole oxidation decreased 35 folds and increased 40 folds for the sulfoxidation of lansoprazole sulfide. The structural mechanism for the selectivity improvement was illuminated to find a selectivity decision pocket that was conservatively present in BVMOs composed of 4 loops. In upscaled reaction system, the substrate loading for MU2 increased from 40 mM to 100 mM for the synthesis of enantiopure ( R )-rabeprazole. The sulfone content decreased from 16.6 % to 1.2 % compared to PockeMO. Lansoprazole sulfide could also be fully converted into enantiopure ( R )-lansoprazole at 50 mM in 4 h by MU2 while PockeMO almost did not have activity. This work indicated the synthetic applicability of MU2 for active pharmaceutical ( R )-prazoles.
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