JOURNAL OF MOLECULAR LIQUIDS
·
2020
·
IF 5.065
Xianzhao Shao,Maifang Zuo,Changchun Zhao,Wei Wang,Zhizhou Li
2,4-diamino-6-(4-pyridyl)-1,3,5-triazine (DAPT) was synthesized and analyzed by nuclear magnetic resonance and Fourier transform infrared spectroscopy , thermogravimetric and elemental analysis techniques as well as by high-resolution transmission electron microscopy. DAPT solubility (in tetrahydrofuran , methanol, ethanol, n-propanol, and isopropanol) in the 288.15–318.15 K range was measured using the static analytical technique. We also performed quantum chemical calculations using Gaussian 09 and determined influence of solvent polarity and solute-solvent interactions on DAPT solubility. Experimental results were treated by modified Apelblat and Buchowski-Ksiazaczak ( λh ) equations as well as by the Wilson and nonrandom two-liquid (NRTL) models. All four models showed excellent agreement. This study provides valuable data for the purification of DAPT at the preferential crystallization procedure.
研究领域:
化学
·
材料科学
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2024
·
IF 7.7
Huanhuan Jin,Ziyuan Wang,Zhongji Pu,Haoran Yu,Yuhuan Chen,Xiaoshu Zhou,Lirong Yang,Shuyun Ju,Jianping Wu
Optically pure 1,2,3,4-tetrahydroquinolines (THQs) represent a class of important motifs in many natural products and pharmaceutical agents. While recent advances on redox biocatalysis have demonstrated the great potential of amine oxidases , all the transformations focused on 2-substituted THQs. The corresponding biocatalytic method for the preparation of chiral 4-substituted THQs is still challenging due to the poor activity and stereoselectivity of the available enzyme . Herein, we developed a biocatalytic kinetic resolution approach for enantiodivergent synthesis of 4-phenyl- or alkyl-substituted THQs. Through structure-guided protein engineering of cyclohexylamine oxidase derived from Brevibacterium oxidans IH-35 A (CHAO), the variant of CHAO (Y215H/Y214S) displayed improved specific activity toward model substrate 4-phenyl substituted THQ (0.14 U/mg, 13-fold higher than wild-type CHAO) with superior ( R )-stereoselectivity ( E > 200). Molecular dynamics simulations show that CHAO Y215H/Y214S allows a suitable substrate positioning in the expanded binding pocket to be facilely accessed, enabling enhanced activity and stereoselectivity . Furthermore, a series of 4-alkyl-substituted THQs can be transformed by CHAO Y215H/Y214S, affording R -isomers with good yields (up to 50 %) and excellent enantioselectivity (up to ee > 99 %). Interestingly, the monoamine oxidase from Pseudomonas fluorescens Pf0–1 ( Pf MAO1) with opposite enantioselectivity was also mined. Together, this system enriches the kinetic resolution methods for the synthesis of chiral THQs.
研究领域:
生物催化
·
有机化学
·
蛋白质工程
·
药物科学
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF CHEMICAL RESEARCH
·
2015
·
IF 0.633
Xiang Jiang,Guo-Wei Yu,Zu-Guang Li,Shi-Peng Chu,Shen-Peng Wang
2,2-Dichloro-4,4,6,6-bis[spiro(2′,2″-dioxy-1′,1″-biphenylyl)]cyclotriphosphazene was synthesised from the reaction of hexachlorocyclotriphosphazene with biphenyl-2,2′-diol. 2,2-Bis(4-formylphenoxy)-4,4,6,6-bis[spiro(2′,2″-dioxy-1′,1″-biphenylyl)]cyclotriphosphazene was obtained from the reaction of 2,2-dichloro-4,4,6,6-bis[spiro(2′,2″-dioxy-1′,1″-biphenylyl)] cyclotriphosphazene with 4-hydroxybenzaldehyde. 2,2-Bis[4-(4-quinazolinone)phenoxy]-4,4,6,6-bis[spiro(2′,2″-dioxy-1′,1″-biphenylyl)]cyclotriphosphazene was synthesised from the reaction of 2,2-bis(4-formylphenoxy)-4,4,6,6-bis[spiro(2′,2″-dioxy-1′,1″-biphenylyl)]cyclotriphosphazene with anthranilamide in N,N-dimethylformamide. The novel cyclophosphazene derivatives were synthesised under mild conditions from the reaction of 2,2-bis[4-(4-quinazolinone)phenoxy]-4,4,6,6-bis[spiro(2′,2″-dioxy-1′,1″-biphenylyl)]cyclotriphosphazene with 4-chlorobenzenemethanethiol, p-thiocresol, 4-aminothiophenol, and 4-chlorothiophenol in the presence of p-toluenesulfonyl chloride via C-OH bond activation under mild conditions. All products were generally obtained in high yields. Their structures were characterised by HRMS, IR and 1H, 13C spectroscopy.
研究领域:
有机化学
·
材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2016
·
IF 1.835
Yingying Shan,Mengfan Fu,Weidong Yan
The solubilities of 4′,5,7-triacetoxyflavanone in eight different alcohols, 2-methoxyethanol, 2-propoxyethanol, 2-butoxyethanol, ethyl acetate, tetrahydrofuran, and acetone have been measured with an HPLC (high-performance liquid chromatography) analysis method at the experimental temperature from 278.2 to 318.2 K. The solubilities of 4′,5,7-triacetoxyflavanone in selected solvents increase with an increasing of temperature. The solubilities of 4′,5,7-triacetoxyflavanone were correlated with the modified Apelblat equation and universal quasichemical (UNIQUAC) equation, respectively. The correlated solubilities were in good accordance with the measured data at the experimental temperature. Furthermore, the crystal habits of 4′,5,7-triacetoxyflavanone in selected solvents were studied in this work.
研究领域:
有机化学
·
药物化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ANALYTICAL AND APPLIED PYROLYSIS
·
2016
·
IF 3.652
Shiliang Wu,Dekui Shen,Jun Hu,Huiyan Zhang,Rui Xiao
The pyrolytic characteristics of cellulose, cellobiose and glucose were examined by TG-FTIR combined with Py-GC–MS, in order to gain the effect of β -O-4 glycosidic bond on the pyrolysis process. In TG-FTIR analysis, two mass loss peaks were observed for cellobiose and glucose, indicating dehydration in low temperature stage and consequently intensive cracking of glycosidic bond and fragments for cellobiose. The samples were tested in Py-GC–MS at the temperature of 300, 500 and 900 °C according to their mass loss characteristics from TG-FTIR. Formation of furans from cellobiose, which involved the cracking of β -O-4 glycosidic bond, was prominent over other products, compared to that of cellulose and glucose. Four possible chemical pathways for the cleavage of β -O-4 glycosidic bond have been proposed with regard to the formation of furans and anhydrosugars from cellulose. Besides, another two reaction pathways leading to the formation of levoglucosan were also suggested.
研究领域:
生物质化学
·
热化学转化
✓ 已验证
产品关联
DOI
高影响因子
Micromachines
·
2023
·Vol. 14
·期 4
·739
·
IF 3.4
Mingjie Han,Yong Xie,Ri Wang,Yang Li,Chao Bian,Shanhong Xia
As a highly toxic heavy metal ion, mercury ion (Hg2+) pollution has caused serious harm to the environment and human health. In this paper, 4-mercaptopyridine (4-MPY) was selected as the sensing material and decorated on the surface of a gold electrode. Trace Hg2+could be detected by both differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS) methods. The proposed sensor displayed a wide detection range from 0.01 μg/L to 500 μg/L with a low limit of detection (LOD) of 0.002 μg/L by EIS measurements. Combined with molecular simulations and electrochemical analyses, the chelating mechanism between Hg2+and 4-MPY was explored. Through the analysis of binding energy (BE) values and stability constants, 4-MPY showed an excellent selectivity for Hg2+. In the presence of Hg2+, the coordination of Hg2+with the pyridine nitrogen of 4-MPY was generated at the sensing region, which caused a change in the electrochemical activity of the electrode surface. Due to the strong specific binding capability, the proposed sensor featured excellent selectivity and an anti-interference capability. Furthermore, the practicality of the sensor for Hg2+detection was validated with the samples of tap water and pond water, which demonstrated its potential application for on-site environmental detection.
研究领域:
环境科学
·
分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2023
·Vol. 140
·期 29
·e54063
·
IF 3
Huan Wang,Zhengzai Cheng,Lesly Dasilva Wandji Djouonkep,Linfeng Wang,Shuanpu Cai,Mario Gauthier
A novel biphenyl monomer, diethyl 6,6′-dimethoxy-[1,1′-bipheny]-3,3′-dicarboxylate (DDBD), was synthesized from 4-hydroxybenzaldehyde, a phenolic compound derived from lignin. A series of polyesters were prepared by polycondensation of the biphenyl monomer with hydroquinone bis(2-hydroxyethyl) ether and aliphatic diacids via a two-step melt polycondensation method. It was shown that the properties of the polyesters can be tuned by varying the length and the structure of the spacer in the aliphatic diacid monomers. Structure–property relations for these materials were investigated by Fourier-transform infrared spectroscopy, nuclear magnetic resonance spectroscopy, gel permeation chromatography (GPC), differential scanning calorimetry, thermogravimetric analysis, and dynamic mechanical analysis. GPC analysis showed that the weight-average molecular weight ( M w ) of the samples varied from 4.2–5.0 × 10 4 g/mol, while thermal analysis yielded T g values of 51–120°C, and 5% decomposition temperatures ( T d,5% ) of 327–389°C. All the samples exhibited a high yield strength (56–87 MPa). After 30 weeks of degradation in soil, the copolyesters had mass losses of up to 4.4%, and an investigation of the ecotoxicity of the copolyesters with Eisenia fetida yielded a survival rate of over 80% after 14 days for the different copolyesters, suggesting low toxicity in the environment. Overall, these copolyesters have good properties and would be suitable to replace petroleum-based commercial poly(ethylene terephthalate) packaging materials.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED MICROBIOLOGY AND BIOTECHNOLOGY
·
2022
·Vol. 106
·期 18
·6277-6287
·
IF 5.56
Yin Ru,Zhang Xue,Wang Beijia,Jia Jianbo,Wang Nana,Xie Chunyan,Su Peiyang,Xiao Pengfei,Wang Jianqiao,Xiao Tangfu,Yan Bing,Hirai Hirofumi
Abstract Environmental bisphenol F (BPF) has a cyclic endocrine disruption effect, seriously threatening animal and human health. It is frequently detected in environmental samples worldwide. For BPF remediation, biological methods are more environmentally friendly than physicochemical methods. White-rot fungi have been increasingly studied due to their potential capability to degrade environmental pollutants. Phanerochaete sordida YK-624 has been shown to degrade BPF by ligninolytic enzymes under ligninolytic conditions. In the present study, degradation of BPF under non-ligninolytic conditions (no production of ligninolytic enzymes) was investigated. Our results showed that BPF could be completely removed after 7-d incubation. A metabolite of BPF, 4,4’-dihydroxybenzophenone (DHBP) was identified by mass spectrometry and nuclear magnetic resonance, and DHBP was further degraded by this fungus to form 4-hydroxyphenyl 4-hydroxybenzoate (HPHB). DHBP and HPHB were the intermediate metabolites of BPF and would be further degraded by P. sordida YK-624. We also found that cytochrome P450s played an important role in BPF degradation. Additionally, transcriptomic analysis further supported the involvement of these enzymes in the action of BPF degradation. Therefore, BPF is transformed to DHBP and then to HPHB likely oxidized by cytochrome P450s in P. sordida YK-624. Furthermore, the toxicological studies demonstrated that the order of endocrine-disrupting activity for BPF and its metabolites was HPHB > BPF > DHBP. Key points
• White-rot fungus Phanerochaete sordida YK-624 could degrade BPF.
• Cytochrome P450s were involved in the BPF degradation.
• The order of endocrine disrupting activity was: HPHB > BPF > DHBP.
Graphical abstract
研究领域:
环境科学
·
微生物学
·
毒理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Materials
·
2022
·Vol. 15
·期 17
·5962
·
IF 3.748
Bo Chen,Yu Liang,Yunjia Song,Yunkai Liang,Jian Jiao,Hong Bai,Ying Li
Host immune response has gradually been accepted as a critical factor in achieving successful implant osseointegration. The aim of this study is to create a favorable immune microenvironment by the dominant release of IL-4 during the initial few days after implant insertion to mitigate early inflammatory reactions and facilitate osseointegration. Herein, the B-TNT/PDA/IL-4 substrate was established by immobilizing an interleukin-4 (IL-4)/polydopamine (PDA) coating on a black TiO2nanotube (B-TNT) surface, achieving on-demand IL-4 release under near infrared (NIR) irradiation. Gene Ontology (GO) enrichment analyses based on high-throughput DNA microarray data revealed that IL-4 addition inhibited osteoclast differentiation and function. Animal experiment results suggested that the B-TNT/PDA/IL-4+Laser substrate induced the least inflammatory, tartrate-resistant acid phosphatase, inducible nitric oxide synthase and the most CD163 positive cells, compared to the Ti group at 7 days post-implantation. In addition, 28 days post-implantation, micro-computed tomography results showed the highest bone volume/total volume, trabecular thickness, trabecular number and the lowest trabecular separation, while Hematoxylin-eosin and Masson-trichrome staining revealed the largest amount of new bone formation for the B-TNT/PDA/IL-4+Laser group. This study revealed the osteoimmunoregulatory function of the novel B-TNT/PDA/IL-4 surface by photothermal release of IL-4 at an early period post-implantation, thus paving a new way for dental implant surface modification.Keywords:photothermal;controlled release;IL-4;PDA;TiO2nanotubes;osseointegration;near-infrared laser;titanium
研究领域:
生物材料
·
免疫学
·
组织工程
·
牙科种植学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Soft Matter
·
2012
·Vol. 8
·期 14
·3756-3761
·
IF 4.39
Xiuqin Cai,Kaiqiang Liu,Junlin Yan,Helan Zhang,Xiaoyu Hou,Zhang Liu,Yu Fang
A novel calix[4]arene-based dimeric-cholesteryl derivative was synthesized, and its gelation behaviour in thirty organic solvents was investigated. It has been shown that the compound cannot gel any of the pure solvents tested. However, it gels a mixture of solvents n-decane and acetonitrile efficiently, provided the volume ratio of the two solvents in a mixture is within 9 : 1 and 3 : 2. AFM and SEM measurements revealed that the molecules of the compound aggregate into micro-/nano-rods first, then fine fibers, and then thick fibers, and finally networked structures in the mixture solvents. Interestingly, the gel with a composition of 1 to 1 (Vn-Decane:VAcetonitrile) and 2.5% (w/v) of the compound exhibits super-smart and fully reversible thixotropic properties, a phenomenon never reported before. Furthermore, the mechanical strength of the gel could be easily adjusted by altering the concentration of the gelator and the composition of the mixture solvents. Further interrogation of the gel revealed that structurally the gel is a gel-emulsion with acetonitrile dispersed in n-decane, a rarely found O/O (oil in oil) gel-emulsion which may find uses in the templated preparation of low-density materials with complicated internal structures.
研究领域:
化学
·
材料科学
·
超分子化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF PHYSICAL CHEMISTRY B
·
2025
·
IF 2.9
Qingxue Li,Danqi Li,Bo Zhuang,Wenkai Zhang,Ran-Ran Feng,Feng Gai
It has been shown that 4-cyanoindole-2′-deoxyribonucleoside (4CNI-NS) is a versatile spectroscopic probe of DNA structure and dynamics, as it can pair with all four natural DNA bases. However, its photophysics have not been examined in detail. Herein, we employed multiple techniques, including static fluorescence spectroscopy, time-resolved fluorescence spectroscopy, transient infrared spectroscopy, and theoretical calculations, to assess the photophysical properties of this nucleoside analogue in a series of solvents. We found that (1) its fluorescence has a large quantum yield (0.85 ± 0.10) and a relatively long decay lifetime (10.3 ± 1.0 ns) in H2O, both of which become smaller in other solvents examined, (2) its maximum fluorescence emission frequency exhibits a linear dependence on the relative polarity index of the solvent, (3) the oscillator strength of its C≡N stretching vibration is increased by a factor of >10 upon transition to its excited electronic state (S1), (4) besides solvent relaxation, a rotational motion around the single bond connecting the pentose group and the indole ring is also present in the S1 state, and (5) in aprotic solvents both processes lead the C≡N stretching frequency (νESA) to shift toward higher frequencies, whereas in protic solvents the effects of these processes are more complex. Taken together, these findings provide a molecular basis for interpreting the spectroscopic signals of this nucleoside analogue in practical applications.
研究领域:
生物化学
·
光谱学
·
理论计算
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MOLECULES
·
2016
·Vol. 21
·期 3
·299
·
IF 2.465
Bo Jin,Rongzong Zheng,Rufang Peng,Shijin Chu
Five new bis(3-hydroxy-4-pyridinone) tetradentate chelators were synthesized in this study. The structures of these tetradentate chelators were characterized by1H-NMR,13C-NMR, FT-IR, UV-vis, and mass spectral analyses. The binding abilities of these tetradentate chelators for uranyl ion at pH 7.4 were also determined by UV spectrophotometry in aqueous media. Results showed that the efficiencies of these chelating agents are dependent on the linker length. Ligand4bis the best chelator and suitable for further studies.Keywords:chelating agent;3-hydroxy-4-pyridinone;uranium;tetradentate chelator
研究领域:
化学
·
环境科学
✓ 已验证
DOI
PubMed
高影响因子
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