ANALYTICAL CHEMISTRY
·
2015
·
IF 5.636
Yu Zhang,Gang Hu,Lin Hu,Jimei Song
This paper reports a novel method for identification of two aliphatic position isomers between α-ketoglutaric acid (α-KA) and β-ketoglutaric acid (β-KA) by their different perturbation effects on a Briggs–Rauscher oscillating system, in which tetraaza-macrocyclic complex [NiL](ClO4)2 is used as the catalyst. The ligand L in the complex is 5,7,7,12,14,14-hexamethyl-1,4,8,11-tetraazacyclotetradeca-4,11-diene. The experimental results have shown that addition of α-KA into the system does not affect the oscillating patterns, while the presence of β-KA in a dynamic system influences the oscillatory amplitude. A more interesting feature is that, in the presence of a higher concentration of β-KA, there are damped oscillations after the initial spike, followed by quenching (more exactly: very small oscillations) of the oscillations before the subsequent regeneration of oscillations. A qualitative approach was thus established by employing a Briggs–Rauscher system for identification of these two isomers. The concentrations of these two isomers that can be distinguished lie over the range between 5.0 × 10–6 and 2.5 × 10–3 mol/L. A reaction mechanism based on the FCA model has been proposed. An explanation is that β-KA reacts with HOO• radicals to form acetone, whereas the α-KA does not.
研究领域:
生物化学
·
分析化学
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产品关联
DOI
PubMed
高影响因子
APPLIED COMPOSITE MATERIALS
·
2021
·Vol. 29
·期 2
·745-764
·
IF 2.181
Zhang Meng,Qian Xin,Ma Kai,Ma Hongbo,Zhang Yonggang
A two-step surface treatment was conducted on high strength and high modulus carbon fibers (HSHM-CFs) to enhance the interfacial properties of polyetherketoneketone (PEKK) matrix composites. In the two-step surface treatment, the surfaces of HSHM-CFs were electrochemically oxidized followed by sizing treatment. Thermoset epoxy (EP) sizing agents and thermoplastic polyetherimide (PEI) sizing agents were utilized for comparison. Results showed that PEI sizing agents had better wetting effects than EP sizing agents. The sizing process led to increases in fiber strength due to healed surface flaws and inhibited micro-crack initiation. Although EP sizing agents were incompatible with PEKK matrix, the interlaminar shear strength (ILSS) of PEKK matrix composites reinforced by EP-sized fibers still increased, compared with that by untreated fibers, due to hydrogen bond and weak chemical reactions between HSHM-CFs and PEKK matrix. The strong interaction between PEI sizing agents and HSHM-CFs, diffusion and entanglement as well as the non-covalent π-π interaction between PEI sizing agents and PEKK matrix resulted in highest ILSS value of PEI-sized HSHM-CF/PEKK composites.
研究领域:
材料科学
·
复合材料工程
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产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
·
2021
·Vol. 22
·期 16
·8949
·
IF 5.924
Huiqing Luo,Na Li,Liyan Liu,Huaqiao Wang,Feng He
Fluorophores with aggregation-induced emission enhancement (AIEE) properties have attracted increasing interest in recent years. On the basis of our previous research, we successfully designed and synthesized eleven chalcones. Through an optical performance experiment, we confirmed that compounds1–6had obvious AIEE properties. As these AIEE molecules had excellent fluorescence properties and a large Stokes shift, we studied their application in living cell imaging, and the results showed that these compounds had low cytotoxicity and good biocompatibility at the experimental concentrations. More importantly, they could specifically label mitochondria. Subsequently, we selected zebrafish as experimental animals to explore the possibilities of these compounds in animal imaging. The fluorescence imaging of zebrafish showed that these AIEE molecules can enter the embryo and can be targeted to aggregate in the digestive tract, which provides a strong foundation for their practical application in the field of biological imaging. Compared with traditional fluorophores, these AIEE molecules have the advantages of possessing a small molecular weight and high flexibility. Therefore, they have excellent application prospects in the field of biological imaging. In addition, the findings of this study have very positive practical significance for the discovery of more AIEE molecules.Keywords:AIEE;chalcone;mitochondria;zebrafish
研究领域:
生物成像
·
分子生物学
·
材料科学
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产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
·
2020
·Vol. 21
·期 24
·9576
·
IF 4.556
Bin Zhang,Xueying Li,Xiuhong Li,Zhigang Lu,Xiaona Cai,Qing Ou Yang,Pengda Ma,Juane Dong
Tanshinones, the major bioactive components inSalvia miltiorrhizaBunge (Danshen), are synthesized via the mevalonic acid (MVA) pathway or the 2-C-methyl-D-erythritol-4-phosphate (MEP) pathway and the downstream biosynthesis pathway. In this study, the bacterial component lipopolysaccharide (LPS) was utilized as a novel elicitor to induce the wild type hairy roots ofS. miltiorrhiza.HPLC analysis revealed that LPS treatment resulted in a significant accumulation of cryptotanshinone (CT) and dihydrotanshinone I (DTI). qRT-PCR analysis confirmed that biosynthesis genes such asSmAACTandSmHMGSfrom the MVA pathway,SmDXSandSmHDRfrom the MEP pathway, andSmCPS,SmKSLandSmCYP76AH1from the downstream pathway were markedly upregulated by LPS in a time-dependent manner. Furthermore, transcription factorsSmWRKY1 andSmWRKY2, which can activate the expression ofSmDXR,SmDXSandSmCPS, were also increased by LPS. Since Ca2+signaling is essential for the LPS-triggered immune response, Ca2+channel blocker LaCl3and CaM antagonist W-7 were used to investigate the role of Ca2+signaling in tanshinone biosynthesis. HPLC analysis demonstrated that both LaCl3and W-7 diminished LPS-induced tanshinone accumulation. The downstream biosynthesis genes includingSmCPSandSmCYP76AH1were especially regulated by Ca2+signaling. To summarize, LPS enhances tanshinone biosynthesis throughSmWRKY1- andSmWRKY2-regulated pathways relying on Ca2+signaling. Ca2+signal transduction plays a key role in regulating tanshinone biosynthesis inS. miltiorrhiza.Keywords:lipopolysaccharide;tanshinones;Ca2+signaling;SmWRKY
研究领域:
植物学
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药理学
·
分子生物学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF CHEMICAL AND ENGINEERING DATA
·
2020
·
IF 2.369
Rongrong Li,Wei Wang,Xianlang Chen,Hong Chen,Huanhuan Bao,Yuwei Zhu,Jia Zhao,Deman Han
This study reports the equilibrium solubility for monobenzone in methanol, ethanol, n-propanol, isopropanol, n-butanol, acetonitrile, ethyl acetate, acetone, 1,4-dioxane, cyclohexane, N,N-dimethylformamide (DMF), N-methyl-2-pyrrolidinone (NMP), n-hexane, n-octanol, and water that was determined by means of the isothermal method between 283.15 and 313.15 K under p = 101.1 kPa. The maximum value of monobenzone solubility was 0.6316 in mole fraction at 313.15 K dissolved in ethyl acetate, but the least data was achieved in water. The solubility of monobenzone increased with the rising temperature and the order followed in the 15 pure solvents was ethyl acetate (0.6316, 313.15 K) > 1,4-dioxane (0.4350, 313.15 K) > methanol (0.1356, 313.15 K) > acetonitrile (0.1247, 313.15 K) > (ethanol, isopropanol) > n-propanol (0.09942, 313.15 K) > n-butanol (0.08346, 313.15 K) > n-octanol (0.03546, 313.15 K) > cyclohexane (8.020×10–3, 313.15 K) > n-hexane (3.133 × 10–3, 313.15 K) > NMP (2.372 × 10–4, 313.15 K) > DMF (1.145 × 10–4, 313.15 K) > acetone (4.032 × 10–5, 313.15 K) > water (3.019 × 10–5, 313.15 K). There was no existence of processes such as solvation or polymorphic transformation during the entire experiment. Several models covering the modified Apelblat, λh, Wilson, and non-random two-liquid models were applied to correlate and calculate monobenzone solubility data in fifteen monosolvents. Results showed that the modified Apelblat equation provided the best results with the experimental ones. The largest relative average deviation and root-mean-square deviation were no more than 4.74 × 10–2 and 1.81 × 10–3, respectively.
研究领域:
药学
·
化学
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产品关联
DOI
高影响因子
FITOTERAPIA
·
2024
·
IF 2.5
Yuan Wei,Wen-Hua Dong,Wei Li,Jun Zeng,Hui-Qin Chen,Sheng-Zhuo Huang,Li Yang,Wen-Li Mei,Ya-Li Wang,Zhi-Yong Guo,Hao-Fu Dai,Hao Wang
Six new dimeric 2-(2-phenylethyl)chromones ( 1 – 6 ) were successfully isolated from the ethanol extract of agarwood of Aquilaria filaria from Philippines under HPLC-MS guidance. Compounds 1 – 6 are all dimers formed by linking 5,6,7,8-tetrahydro-2-(2-phenylethyl)chromone and flindersia 2-(2-phenylethyl)chromone via a single ether bond, and the linkage site (C5-O-C8′′) of compound 2 is extremely rare. A variety of spectroscopic methods were used to ascertain their structures, including extensive 1D and 2D NMR spectroscopic analysis, HRESIMS, and comparison with literature. The in vitro tyrosinase inhibitory and anti-inflammatory activities of each isolate were assessed. Among these compounds, compound 2 had a tyrosinase inhibition effect with an IC 50 value of 27.71 ± 2.60 μM, and compound 4 exhibited moderate inhibition of nitric oxide production in lipopolysaccharide-stimulated RAW264.7 cells with an IC 50 value of 35.40 ± 1.04 μM.
研究领域:
植物化学
·
药理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Engineering
·
2025
·
IF 11.6
Qingrui Zeng,Ziang Jia,Yingyang Song,Yiwen Fan,Xu Liu,Jinping Cheng
Carbon dioxide capture and storage (CCS) is an important technological path for realizing “carbon neutrality,” where carbon capture is one of the three key CCS technologies. At present, mature carbon capture technologies still have technical shortcomings and difficulties, such as low capture efficiency and high energy consumption, which limit their large-scale popularization and application. In this study, a solid–liquid phase change absorbent (PCA) system with isophorone diamine (IPDA) as the only carbon dioxide (CO 2 ) capture carrier and ketone-based organic molecules as the phase change medium was developed. The solid–liquid PCA system has a wide range of applicability, with highly efficient CO 2 capture (1.11 mol·mol −1 ) at concentrations ranging from typical values in air to those in coal-fired industrial emissions (400 to 150 000 ppm) and low-energy consumption regeneration, as revealed by a two-phase integrated engineering model. The CO 2 absorption product IPDA(NHCOO − ) 2 was characterized by materials science analysis, molecular dynamics (MD) calculations and quantum chemistry. The results indicate that in noncyclic ketone-based phase-change media, the hydrogen bonding in IPDA(NHCOO − ) 2 is modulated by noncovalent bond interaction (NCI) forces to form a small-scale hydrogen-bonding network. These properties ensure that the product can be easily regenerated by low-temperature thermal treatment (333 K, 60 °C), and characterization and calculations revealed a reaction mechanism different from that of the aqueous system. The technoeconomic evaluation (TEA) results show that this type of ketone-based PCA has an obvious low-cost advantage over traditional carbon capture technologies. This study provides a new perspective on the application and practical feasibility of PCAs for direct air capture of carbon dioxide.
研究领域:
化学工程
·
环境科学
·
材料科学
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产品关联
DOI
高影响因子
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
·
2025
·
IF 6.2
Bin Ma,Jiafeng Niu,Hao Zhu,Huibing Chi,Zhaoxin Lu,Fengxia Lu,Ping Zhu
Aldo-keto reductase is responsible for the formation of nontoxic 3-epi-deoxynivalenol (3-epi-DON) from 3-keto-DON, which is an enzymatic detoxification manner to completely eliminate the toxicity of mycotoxin DON against health and environmental threats. Therefore, unlocking the facilitated substrate specificity of aldo-keto reductase for 3-keto-DON has become a critical challenge for advanced catalytic performance. In this endeavor, a loop-based engineering strategy was developed for aldo-keto reductase AKR13B3 from Devosia A6–243 to catalyze 3-keto-DON. A 31.9-fold switch from a disfavored substrate to the preferred one was produced along with a significant 37.9-fold increase in catalytic efficiency. Kinetic parameter determinations, structural analyses, and molecular simulations were employed to elucidate the molecular mechanisms underlying these enhancements in catalytic activity and substrate specificity. Overall, our work presents a feasible scheme for designing aldo-keto reductases with exceptional substrate specificity and catalytic activity, holding great promise for developing enzymatic detoxification agents.
研究领域:
生物化学
·
分子生物学
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
POLYMER
·
2015
·
IF 3.562
Jiangtao Liu,Guofei Chen,Junchao Guo,Nafeesa Mushtaq,Xingzhong Fang
A series of cardo poly(ether ketone imide)s (PEKI-C) containing large-volume bulky phthalide groups were prepared by aromatic nucleophilic substitution reaction of commercially available phenolphthalein and 4,4′-bis(4-fluorophthalimido)diphenyl ether/4,4′-difluorobenzophenone. The glass transition temperatures ( T g s) increased from 221 to 278 °C with increasing the content of 4,4′-bis(4-fluorophthalimido)diphenyl ether moiety in the copolymerization . The 5% weight loss temperatures ( T 5% ) of PEKI-C ( a–e ) reached up to 472–495 °C in nitrogen and 466–481 °C in air. Flexible films, which could be easily cast from the polymer solutions , exhibited good mechanical properties with tensile strengths of 73–124 MPa, elongations at break of 9.7–12.8%, and tensile moduli of 2.2–2.8 GPa. Their films with cut-off wavelengths from 336 to 368 nm were transparent and essentially colorless. It is noted that the T g , T 5% , tensile strengths, elongations at break, and tensile moduli of PEKI-C ( a–e ) increased with increasing the content of 4,4′-bis(4-fluorophthalimido)diphenyl ether in the copolymerization.
研究领域:
材料科学
·
高分子化学
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产品关联
DOI
高影响因子
JOURNAL OF THE BRAZILIAN CHEMICAL SOCIETY
·
2017
·Vol. 28
·期 10
·1866-1873
·
IF 1.198
Yin Qinhong,Zhu Yanqin,Yang Yaling
Oleic acid modified Fe3O4 nanoparticles were proposed for magnetic solid-phase extraction coupled with ultra high-performance liquid chromatography-tandem mass spectrometry to determine risperidone (RISP) and 9-hydroxyrisperidone (9OHR) in biological samples. The effects of various experimental parameters including adsorbent amount, pH, adsorption time, eluent type and concentration were systematically investigated. Under optimal conditions, the calibration curve was linear within the concentration range of 0.2-200 ng mL-1 with the correlation coefficient (r) of 0.9962 and the lower limit of quantification was 0.06 ng mL-1 for RISP; the calibration curve was linear within the concentration range of 0.2-200 ng mL-1 with the correlation coefficient of 0.9956 and the lower limit of quantification was 0.04 ng mL-1 for 9OHR. The extraction recoveries were over 90.0% with relative standard deviation less than 5.0%. All these results suggested that magnetic extraction method can be used for enrichment and quantification of RISP and 9OHR in biological samples.
研究领域:
分析化学
·
药物分析
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产品关联
DOI
高影响因子
FOOD CHEMISTRY
·
2024
·
IF 8.5
Guojian Deng,Lunfang Huang,Wenya Wang,Tianzi Yu,Jingming Ning,Yujie Wang
The intensity of green tea's floral and sweet flavors was enhanced after being scented by osmanthus (OSGT). However, the mechanism of flavor enhancement by key volatiles remains unknown. Here, the role of key volatiles in OSGT on aroma and taste was explored by sensory experiment-guided flavor analysis. Binary mixed models of ( E )- β -ionone, dihydro- β -ionone, and α -ionone showed additive interactions on floral aroma enhancement, the interactions were increased with increasing concentrations. At the concentration in OSGT, binary mixed models of ( E )- β -ionone, geraniol , linalool , and γ -decalactone showed additive interactions on sweet aroma enhancement. ( E )- β -ionone, geraniol , linalool , and γ -decalactone all significantly increased the perceived intensity of sweetness of sucrose solutions. Additionally, molecular docking revealed the perception mechanism of olfactory and taste receptors to the above characterized volatiles, with hydrogen bonding and hydrophobic interactions being the main interactions. This study highlights the importance of characteristic volatiles in enhancing the flavor of OSGT.
研究领域:
食品科学
·
香气化学
·
感官科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Food Quality and Safety
·
2024
·
IF 3
Liu Yilong,You Wenwen,Wang Ruoqi,Zeng Tao,Zhao Xiaoyong,Cao Yunlin,Zhang Wenna,Nie Zongxing,Yang Xiaochun,Li Xian
Hawthorn (Crataegus spp.) is a functional food with long medical usage and excellent health-promoting effects. In this study, comparative metabolomics analysis between the yellow hawthorn berry (Crataegus pinnatifida) and the red-skinned ones was first carried out with the peel and flesh separated to fully understand the polyphenol composition and metabolite variations. A total of 453 polyphenols was characterized, among which phenolic acids and flavonoids were abundant, and were closely relevant to the antioxidant capacity of hawthorn fruits. Polyphenol profile showed accession-specific accumulation in peel or flesh of different colored hawthorn. The unique yellow hawthorn was found to have few anthocyanins but show enhanced flux to synthesize flavones and flavonols, especially flavone C-glycosides and acylated flavonol glycosides. The specific acylation decoration includes acetylation, p-coumaroylation, and malonylation. In addition, the yellow hawthorn showed excellent α-glucosidase inhibitory effect, which might be associated with the high concentration of 8 polyphenols including 5 phenolic acids, 2 flavone C-glycosides, and an acylated flavonol glycoside, namely quercetin-7-O-(6''-malonyl)glucoside. Such acylated flavonol showed the highest correlation ship with the inhibition effect of hawthorn fruits on α-glucosidase, and was predicted to had the lowest binding energy with the enzyme by molecular docking analysis, indicating its great potential as a strong α-glucosidase inhibitors and an important antidiabetic ingredient in yellow hawthorn. Thus, acylated flavonol glycosides and C-glycosyl flavones might be chemotaxonomic markers differentiating varieties and bioactivities of yellow hawthorn from the traditional red-skinned ones. These findings complement the existing knowledge on the metabolite composition and nutritional properties of hawthorn fruits.
研究领域:
食品科学
·
代谢组学
·
营养学
·
药理学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）