JOURNAL OF CHEMICAL THERMODYNAMICS
·
2019
·
IF 2.29
Yameng Wan,Rui Zhao,Pengshuai Zhang,Haixia He,Jiao Sha,Tao Li,Baozeng Ren
Solubility of ( R )-(-)-phenylephrine hydrochloride ( R -PEHC) in ten pure solvents including methanol (MtOH), ethanol (EtOH), n -propanol (NPrOH), iso-propanol (IPrOH), 2-methoxyethanol, 2-ethoxyethanol, 2-propoxyethanol, 2-butoxyethanol, N-methyl pyrrolidone (NMP) and N,N-dimethylformamide (DMF) was determined by using a laser monitoring technique in the range of 278.15 K to 323.15 K under 0.1 MPa. Solubility of R -PEHC increases with the increment of temperature. The solvent effect on R -PEHC solubility was investigated by the linear solvation energy relationships concept (Kamlet-Taft parameters). The interaction energy ( E inter ) between R -PEHC and selected solvents was calculated by molecular simulation to explain the solubility behavior. Experimental solubility was correlated by five activity coefficient models including the Two-Suffix Margules model, Wilson model, NRTL model, NRTL-SAC model and uniquac model. Five models can fit experimental solubility values well. Furthermore, thermodynamic properties of solutions of R -PEHC in selected solvents were investigated by the van’t Hoff equation.
研究领域:
物理化学
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热力学
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药学
·
分子模拟
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DOI
高影响因子
JOURNAL OF MOLECULAR LIQUIDS
·
2023
·
IF 6
Boxuan Lou,Yue Xu,Xiaolan Qin,Chang Liu,Shujun Wang,Haikuan Yuan,Xijian Liu,Lijuan Zhang,Jie Lu
In this work, the solubility of unsolvated crystalline (R)-equol in six (alcohols + n -heptane) binary solvents and that of solvated crystalline (R)-equol in methanol along with ethanol were firstly systematically measured and analyzed. The experimental results revealed that the solubility of unsolvated crystalline (R)-equol was positively correlated with temperature and mass fraction of alcohol. And the solubility order was 2-propanol > 1-propanol > 1-butanol > 1-pentanol > 3-methyl-1-butanol > 2-methyl-1-propanol > n -heptane. The transformation temperatures between unsolvated and solvated forms were acquired at 316.28 K and 310.50 K, respectively. Meanwhile, the experimental solubility data of unsolvated crystalline (R)-equol were correlated using modified Apelblat, λh , quartic polynomial and CNIBS/R-K equations, in which the modified Apelblat equation achieved the best regression performance. Besides, the dissolution of unsolvated crystalline (R)-equol was endothermic. Furthermore, solvent parameters, solvation free energy and molecular electrostatic potential surface obtained through molecular simulation were used to explain the experimental phenomena, and found the polarity of solvents, van der Waals and hydrogen bonding interactions made different contributions to various dissolution processes.
研究领域:
药学
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物理化学
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分子模拟
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产品关联
DOI
高影响因子
PHYTOMEDICINE
·
2024
·
IF 6.7
Wen-lin Li,Ke Li,Wen-guang Chang,Hui Shi,Wen-xuan Zhang,Zi Wang,Wei Li
Background Although our previous work confirmed 20(R)-ginsenoside Rg3 (R-Rg3), which is an active ingredient in the Panax Ginseng C.A. Meyer, to have good anti-diabetic activity, its beneficial effect on diabetic retinal injury was found to be limited. Purpose This study aims to investigate the protective effects of R-Rg3 on diabetes-induced retinal injury and the associated molecular mechanisms of action. Methods Diabetic retinal injury was induced in mice using a combination of a high-fat diet (HFD) and intraperitoneal injection of streptozotocin (STZ). R-Rg3 (10 and 20 mg/kg) was subsequently administered for 6 weeks. The human retinal endothelial cells (HRECs) were subjected to high glucose (HG)-induced injury for the in vitro analysis and treated with R-Rg3 (4, 8, 16 μM), antioxidant N-Acetylcysteine (NAC, 1 mM) and Nrf2 inhibitor ML385 (5 μM). The mice retinas then underwent functional and histopathological analysis. Expression levels of proteins related to the Nrf2/HO-1 axis, tight junction proteins, endoplasmic reticulum (ER) stress and the apoptosis in retinal tissue and HRECs were determined by western blot. Expressions of ZO-1 and Nrf2 in the retina and HRECs were assessed by immunofluorescence. Additional evaluations included measuring body weights, fasting blood glucose (FBG), lipid levels and oxidative markers. Results The results showed 6 weeks of R-Rg3 treatment significantly restored the functional changes and redox system imbalance that was induced by HFD/STZ in mice. R-Rg3 was also found to significantly reduce retinal barrier damage and thickness changes resulting from hyperglycaemia exposure. At the same time, R-Rg3 also protected HRECs from HG-induced damage. R-Rg3 could also activate Nrf2/HO-1 axis and inhibit endoplasmic reticulum stress as a means of alleviating retinal endothelial cells apoptosis. The molecular docking results also demonstrated that R-Rg3 had a good binding ability with Nrf2. Conclusion Our study suggested Nrf2/HO-1 axis might be crucial for the ability of R-Rg3 to prevent diabetic retinal injury.
研究领域:
药理学
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糖尿病
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眼科学
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分子生物学
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细胞生物学
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产品关联
DOI
PubMed
高影响因子
BIOORGANIC CHEMISTRY
·
2024
·
IF 4.5
He Liu,Shixi Wang,Meng Xu,Kaiyue Zhang,Qian Gao,Hualei Wang,Dongzhi Wei
( R )-selective transaminases show promise as catalysts for the asymmetric synthesis of chiral amines, which are building blocks of various small molecule drugs. However, their application is limited by poor substrate acceptance and low catalytic efficiency. Here, a potential ( R )-selective transaminase from Fodinicurvata sediminis (FsTA) was identified through a substrate truncating strategy, and used as starting point for enzyme engineering toward catalysis of 4-hydroxy-2-butanone, a substrate that poses challenges in catalysis. Molecular docking and dynamics simulations revealed Y90 as the key residue responsible for poor substrate binding. Starting from the variant (Y90F, mut1) with initial activity, FsTA was systematically modified to improve substrate-binding through active site reshaping and consensus sequence strategy, yielding three variants (H30R, V152K, and Y156F) with improved activity. A quadruple mutation variant H30R/Y90F/V152K/Y156F (mut4) was also found to show a 7.95-fold greater catalytic efficiency ( k cat / K M ) than the initial variant mut1. Furthermore, mut4 also enhanced the thermostability of enzyme significantly, with the T m value increasing by 10 °C. This variant also exhibited significantly improved activity toward a series of ketones that are either not accepted or poorly accepted by the wild-type. This study provides a basis for the rational design of an active to creating variants that can accommodate novel substrates.
研究领域:
生物化学
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酶工程
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产品关联
DOI
PubMed
高影响因子
Small
·
2023
·Vol. 19
·期 25
·2300938
·
IF 13.3
Jian Chen,Xin Pan,Xuanyu Zhang,Chen Sun,Congcong Chen,Xiaoqin Ji,Rui Chen,Lingling Mao
Chiral organic−inorganic hybrid metal halide materials have shown great potential for circularly polarized luminescence (CPL) related applications for their tunable structures and efficient emissions. Here, this work combines the highly emissive Cu 4 I 4 cubane cluster with chiral organic ligand R / S -3-quinuclidinol, to construct a new type of 1D Cu-I chains, namely Cu 4 I 4 ( R / S -3-quinuclidinol) 3 , crystallizing in noncentrosymmetric monoclinic P 2 1 space group. These enantiomorphic hybrids exhibit long-term stability and show bright yellow emission with a photoluminescence quantum yield (PLQY) close to 100%. Due to the successful chirality transfer from the chiral ligands to the inorganic backbone, the enantiomers show intriguing chiroptical properties, such as circular dichroism (CD) and CPL. The CPL dissymmetry factor ( g lum ) is measured to be ≈4 × 10 −3 . Time-resolved photoluminescence (PL) measurements show long averaged decay lifetime up to 10 µs. The structural details within the Cu 4 I 4 reveal the chiral nature of these basic building units, which are significantly different than in the achiral case. This discovery provides new structural insights for the design of high performance CPL materials and their applications in light emitting devices.
研究领域:
材料科学
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光电
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光子学
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无机化学
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有机-无机杂化材料
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DOI
高影响因子
JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS
·
2018
·
IF 2.207
Renping Cao,Guanjun Quan,Zhihui Shi,Ting Chen,Zhiyang Luo,Guotai Zheng,Zuofu Hu
La 2 Zr 2 O 7 :R (R = Sm 3+ , Bi 3+ , Sm 3+ /Bi 3+ ) phosphors are synthesized by solid-state reaction method in air. Blue emission band peaking at ∼462 nm of La 2 Zr 2 O 7 :Bi 3+ phosphor with excitation at 312 nm is observed in the range of 370–610 nm due to 3 P 1 → 1 S 0 transition of Bi 3+ ion and D → 1 S 0 transition between Bi 3+ and Zr 4+ ions. La 2 Zr 2 O 7 :Sm 3+ phosphor with excitation at 407 nm shows reddish orange light in the range of 550–750 nm owing to 4 G 5/2 → 6 H J ( J = 5/2, 7/2, 9/2, and 11/2) transitions of Sm 3+ ion. Tunable emission from blue to white of La 2 Zr 2 O 7 :Sm 3+ , Bi 3+ phosphor with excitation at 312 nm can be observed due to the changing Bi 3+ or Sm 3+ ion concentration . La 2 Zr 2 O 7 :Sm 3+ , Bi 3+ phosphor with excitation at 407 nm only emits reddish orange because Bi 3+ has no absorption at 407 nm. The energy transfer from Bi 3+ to Sm 3+ is discussed. The luminous mechanism is explained by the energy level diagrams of Bi 3+ and Sm 3+ ions.
研究领域:
材料科学
·
光学
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产品关联
DOI
高影响因子
JOURNAL OF ANALYTICAL TOXICOLOGY
·
2020
·Vol. 44
·期 6
·596-600
·
IF 3.513
Wang Ting,Shen Baohua,Wu Hejian,Gu Jun,Shen Min,Xiang Ping
In this study, the relationships between the concentrations of R/S-methamphetamine (MA) and its metabolite R/S-amphetamine (AP), the AP/MA ratio in hair samples, and MA dependence were investigated by performing segmental hair analysis in MA users. Authentic hair samples collected from 10 chronic MA abusers were cut into 1-cm sections (a total of 120 segments). The concentrations of MA and AM enantiomers were quantitatively measured by the LC–MS-MS method. The S-MA concentrations ranged from 1.17 to 256.41 ng/mg and the S-AP concentrations ranged from 0.11 to 23.31 ng/mg in the 120 segments. S-MA and S-AP were the most common analytes identified in hair; no R-MA or R-AP was found. The S-AP/S-MA ratios ranged from 0.03 to 0.32, indicating that the subjects primarily consumed S-MA rather than R-MA or AP. The S-AP/S-MA ratios in the long hair of all chronic MA abusers showed some variation, but there was an overall trend of gradual increase from the distal to the proximal end. This trend was independent of the drug concentrations. Therefore, we could conclude that the AP/MA ratios increased with the duration of MA abuse, and a higher AP/MA ratio suggested high MA dependence. There was no chiral conversion of MA or AP in the hair matrix. The segmental hair analysis showed that all subjects continuously used S-MA, and some users showed an increase in drug dose or the frequency of use.
研究领域:
毒理学
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法医学
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药物滥用研究
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF MOLECULAR RECOGNITION
·
2020
·Vol. 33
·期 8
·e2844
·
IF 2.214
Lu Wang,Yanhong Wang,Binbin Zhou,Ming Zhong
A novel type of magnetic molecularly imprinted polymers (MMIP) as the solid-phase extraction sorbent was prepared, which can extract effectively the allocryptopine from the waster of Macleaya cordata (Willd) R . Br . In this study, MMIP was synthesized by using Fe 3 O 4 @SiO 2 , 4-vinyl-pyridine, ethylene glycol dimethacrylate, and allocryptopine, and these ingredients worked as magnetic core, functional monomer, cross-linker, and template, respectively. Concluded by the calculation of Gaussian 09 software, different ratio models of 4-vinyl-pyridine and allocryptopine were simulated, and the optimal ratio was 1:5 and the energy was −2205.34 kJ/mol. Transmission electron microscopy, vibration sample magnetometry, X-ray diffraction, Fourier transform infrared spectroscopy, and thermogravimetric analysis were used to determine the morphology and structure of MMIP. Furthermore, the results of adsorption experiments indicated that MMIP had high selectivity, excellent recyclability, and good adsorption performance (9.86 mg/g, 298 K). The adsorption process was consistent with the Langmuir adsorption isotherm ( R 2 > 0.98, 298 K) and pseudo-second-order kinetics model ( R 2 > 0.99, 298 K). After six times adsorption-desorption experiments, the adsorption amount of MMIP only reduced to 8.5%. In the experiments of selective adsorption, MMIP has better adsorption properties for allocryptopine (ALL, C 21 H 23 NO 5 ) than those having the same functional group. The limit of detection (LOD) was 0.4 μg/mL. The relative standard deviation ranged from 0.09% to 0.72%. The recovery of allocryptopine in samples ranged from 93.60% to 106.19%. In addition, the synthesized complex had a certain adsorption effect on allocryptopine separating from the wastewater of Macleaya cordata (Willd) R . Br .
研究领域:
环境科学
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分析化学
·
材料科学
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DOI
高影响因子
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY
·
2025
·Vol. 61
·期 2
·338-345
·
IF 0.9
Li Chonglong,Lai Caiyun,Zhan Murong,Zhao Xiaona,Dong Wenyuan,Liu Jiaqi,Wang Peibiao
A novel helical poly(phenyl isocyanide) bearing an ( R,R )-(‒)-1,2-diaminocyclohexane pendant (poly- 2 200 ) was designed and synthesized. Helical poly- 2 200 showed an excellent catalytic performance in the asymmetric aldol reaction between cyclohexanone and 2-(trifluoromethyl)benzaldehyde in ethanol: the reaction product had an enantiomeric excess ( ee ) of 87.8%.
研究领域:
有机化学
·
催化化学
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DOI
高影响因子
JOURNAL OF LUMINESCENCE
·
2020
·
IF 3.28
Renping Cao,Yuan Ren,Ting Chen,Wenhao Wang,Qingdong Guo,Qianglin Hu,Chenxing Liao,Ting Fan
A series of SrZrSi 2 O 7 :R (R = Sm 3+ , Bi 3+ , Bi 3+ /Sm 3+ ) phosphors are synthesized successfully in air via high temperature solid-state reaction method. The crystal structure, lifetime, energy transfer (ET) process, and luminescence properties of samples are investigated in detail. Host SrZrSi 2 O 7 with excitation at 300 nm ultraviolet (UV) light emits blue light due to the Zr 4+ - O 2− transition inside [ZrO 6 ] group. SrZrSi 2 O 7 :Bi 3+ phosphor with excitation at 315 nm UV light emits blue light owing to the 3 P 0,1 → 1 S 0 transitions of Bi 3+ ion. SrZrSi 2 O 7 :Sm 3+ and SrZrSi 2 O 7 :Sm 3+ , Bi 3+ phosphors with excitation at 300 nm UV light show a tunable emission due to ET process from [ZrO 6 ] to Sm 3+ and from Bi 3+ to Sm 3+ , respectively, and they only emit red-orange light under excitation 407 nm because of the 4 G 5/2 → 6 H 5/2 , 6 H 7/2 , 6 H 9/2 , and 6 H 11/2 transitions of Sm 3+ ion. The optimal concentrations of Sm 3+ and Bi 3+ ions are ~6 and 4 mol%, respectively. The lifetime of SrZrSi 2 O 7 :Sm 3+ phosphor decreases from 1.127 ms to 0.897 ms with increasing Sm 3+ concentration in the range of 2–12 mol%, and that of SrZrSi 2 O 7 :6%Sm 3+ , Bi 3+ phosphor decreases from 1.005 ms to 0.948 ms with increasing Bi 3+ concentration in the range of 1–8 mol%. The luminous mechanisms of samples are explained by the energy level diagram. The experimental results are helpful for the luminescence improvement and emission adjustion of other Sm 3+ -doped phosphors.
研究领域:
材料科学
·
光学
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产品关联
DOI
高影响因子
ACS Omega
·
2023
·
IF 4.1
Long Liu,Jinhu Bai,Ze Su,Yuan Yao,Zhixiang Zhou,Yangfeng Xia,Yanqiang Zhang
In this paper, a series of energetic ionic liquid plasticizers of 1-methyl-4-methoxyethyl-1,2,4-triazolium chloride (1), 1-methyl-4-methoxyethyl-1,2,4-triazolium bis(trifluoromethylsulfonyl)imide (1a), 1-methyl-4-methoxyethyl-1,2,4-triazolium nitrate (1b), 1-methyl-4-ethyl acetate-1,2,4-triazolium chloride (2), 1-methyl-4-ethyl acetate-1,2,4-triazolium bis(trifluoromethylsulfonyl)imide (2a), and 1-methyl-4-ethyl acetate-1,2,4-triazolium nitrate (2b) were synthesized and characterized. The results show that compounds 1a, 1b, 2a, and 2b have lower melting points (Tm, −72.60 to −32.67 °C) and good thermal stability (Td, 161–348 °C) and are suitable as plasticizers for hydroxyl-terminated polybutadiene (HTPB) curing systems. Among these four ionic liquids, ester-functionalized cations can help to improve the tensile strength (2a, 0.943 MPa; 2b, 1.113 MPa) of the cured system, while ether-functionalized cations are more beneficial to improve elongation at break (1a, 522.90%; 1b, 484.45%). Ester-functionalized ionic liquids are more beneficial to reduce the glass transition temperature of HTPB elastomers. The storage modulus of HTPB elastomers containing NO3– is higher, while that of HTPB elastomers containing NTf2– is lower. The crosslink densities of HTPB/TDI/2a and HTPB/TDI/2b plasticized by ester-functionalized ionic liquids are larger, which are 9369 and 9616 mol/m3, respectively. There are hydrogen bond interactions between the ionic liquid and the HTPB elastomer, and these interactions changed the distribution of the hard and soft segments in the polymer molecules.
研究领域:
含能材料
·
高分子科学
·
推进剂化学
·
材料工程
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DOI
高影响因子
MATERIALS RESEARCH BULLETIN
·
2017
·
IF 2.446
Changlin Liao,Renping Cao,Wudi Wang,Wen Hu,Guotai Zheng,Zhiyang Luo,Pan Liu
NaY(MoO 4 ) 2 :R (R = Sm 3+ /Bi 3+ , Tb 3+ /Bi 3+ , Sm 3+ /Tb 3+ ) phosphors are synthesized by solid-state reaction method in air. The crystal structures, excitation and emission spectra, luminescence properties, the lifetimes, and the dopant concentration influences are investigated. The emission intensity of activators Sm 3+ and Tb 3+ can be enhanced ∼3.04 and 1.64 times due to energy transfer (ET) from Bi 3+ to Sm 3+ /Tb 3+ . NaY(MoO 4 ) 2 :Sm 3+ , Tb 3+ phosphor with excitation 300 nm shows a tunable emission from red to yellow with change Sm 3+ or Tb 3+ ion concentration. Emission intensity of NaY(MoO 4 ) 2 :Sm 3+ phosphor can be enhanced ∼2.24 times via co-doping Tb 3+ ion owing to ET from Tb 3+ to Sm 3+ ions. The results indicate that ET between sensitizer and activator (Bi 3+ → Tb 3+ , Bi 3+ → Sm 3+ , and Tb 3+ → Sm 3+ ) is beneficial to improve the luminescence properties of activator (Sm 3+ and Tb 3+ ). ET and luminous meachanisms are explained by energy level diagrams of Bi 3+ , Tb 3+ , and Sm 3+ ions.
研究领域:
材料科学
·
发光材料
·
光学物理
·
固态化学
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DOI
高影响因子
危险品化学品经营许可证（带存储）