期刊:
Food Research International,2023年163:112278 ISSN:0963-9969
通讯作者:
Xiao-Hua Zhang<&wdkj&>Xiao-Li Yin
作者机构:
[Zhang, Xiao-Hua; Zhang, Ya-Qian; Pan, Le-Yuan; Zheng, Jing-Jing; Yang, Kai-Long; Ren, Lu-Meng] Xuchang Univ, Food & Pharm Coll, Henan Key Lab Biomarker Based Rapid detect Technol, Xuchang 461000, Peoples R China.;[Cui, Hui-Na; Yin, Xiao-Li] Yangtze Univ, Coll Life Sci, Jingzhou 434023, Peoples R China.;[Qing, Xiang-Dong] Hunan City Univ, Coll Mat & Chem Engn, Hunan Prov Key Lab Dark Tea & Jin Hua, Yiyang 413049, Peoples R China.
通讯机构:
[Xiao-Hua Zhang] H;[Xiao-Li Yin] C;Henan Key Laboratory of Biomarker Based Rapid-detection Technology for Food Safety, Food and Pharmacy College, Xuchang University, Xuchang 461000, PR China<&wdkj&>College of Life Sciences, Yangtze University, Jingzhou 434023, China
关键词:
Green tea;Harvesting season;Aqueous two-phase systems;HPLC-DAD;Chemometrics
摘要:
The flavor and aroma quality of green tea are closely related to the harvest season. The aim of this study was to identify the harvesting season of green tea by alcohol/salt-based aqueous two-phase system (ATPS) combined with chemometric analysis. In this paper, the single factor experiments (SFM) and response surface methodology (RSM) optimization were designed to investigate and select the optimal ATPS. A total of 180 green tea samples were studied in this work, including 86 spring tea and 94 autumn tea. After the active components in green tea samples were extracted by the optimal ethanol/(NH(4))(2)SO(4) ATPS, the qualitative and quantitative analysis was realized based on HPLC-DAD combined with alternating trilinear decomposition-assisted multivariate curve resolution (ATLD-MCR) algorithm, with satisfactory spiked recoveries (86.00%-112.45%). The quantitative results obtained from ATLD-MCR model were subjected to chemometric pattern recognition analysis. The constructed partial least squares-discriminant analysis (PLS-DA) and orthogonal partial least squares-discriminant analysis (OPLS-DA) models showed better results than the principal component analysis (PCA) model, and the R(2)X(cum) values (>0.835) and R(2)Y(cum) (>0.937) were close to 1, the Q(2)(cum) values were greater than 0.75 (>0.933), and the differences between R(2)Y(cum) and Q(2)(cum) were not larger than 0.2, indicating excellent cross-validation prediction performance of the models. Furthermore, the classification results based on the hierarchical clustering analysis (HCA) were consistent with the PCA, PLS-DA and OPLS-DA results, establishing a good correlation between tea active components and the harvesting seasons of green tea. Overall, the combination of ATPS and chemometric methods is accurate, sensitive, fast and reliable for the qualitative and quantitative determination of tea active components, providing guidance for the quality control of green tea.
通讯机构:
[Xu, S ] U;[Shi, L ; Xu, S] H;Hunan Univ, Coll Chem & Chem Engn, State Key Lab Chemo Biosensing & Chemometr, Changsha 410082, Peoples R China.;Univ Jinan, Sch Chem & Chem Engn, Jinan 250022, Peoples R China.
摘要:
We propose a practical strategy to design a series of heavy-atom-free synergistic phototherapy agents (CSQs) with both photodynamic therapy (PDT) and photothermal therapy (PTT) under NIR wavelength excitation by simply replacing the indole salt of xanthene Changsha (CS) with quinoline salt.
期刊:
The Journal of Organic Chemistry,2022年87(9):6052-6063 ISSN:0022-3263
通讯作者:
Shanping Chen<&wdkj&>Guo-Jun Deng
作者机构:
[Fang, Fang; Chen, Shanping; Deng, Guo-Jun; Zheng, Haolin] Xiangtan Univ, Coll Chem,Minist Educ, Key Lab Environmentally Friendly Chem & Applicat, Key Lab Green Organ Synth & Applicat Hunan Prov, Xiangtan 411105, Peoples R China.;[Fang, Fang] Hunan City Univ, Coll Mat & Chem Engn, Yiyang 413000, Peoples R China.;[Mao, Guojiang] Henan Normal Univ, Sch Chem & Chem Engn, Xinxiang 453007, Henan, Peoples R China.
摘要:
A novel strategy for the preparation of functional carbazoles through NaI-catalyzed formal [4 + 2] annulation of 2-(indol-3-yl)cyclohexanones and alkynes/alkenes has been developed. The present approach started from easily available raw materials and provided a variety of tetrahydrobenzo[c]carbazolones in satisfactory yields under metal- and solvent-free conditions. Furthermore, the products could be further transformed into structurally valuable carbazole-based conjugated derivatives.
作者机构:
[Liu, Saiwen; Zhang, Jin; Liu, SW; Zhang, J] Hunan City Univ, Coll Mat & Chem Engn, Yiyang 413000, Peoples R China.;[Chen, Ru] Yiyang Agr Prod Qual Detect Ctr, Yiyang 413000, Peoples R China.
通讯机构:
[Liu, SW; Zhang, J] H;Hunan City Univ, Coll Mat & Chem Engn, Yiyang 413000, Peoples R China.
关键词:
additive-free;copper;redox
摘要:
A simple copper-catalyzed redox coupling of sodium sulfinates and nitroarenes is described. In this process, abundant and stable nitroarenes serve as both the nitrogen sources and oxidants, and sodium sulfinates act as both reactants and reductants. A variety of aromatic sulfonamides were obtained in moderate to good yields with broad substrate scope. No external additive is employed for this kind of transformation.
作者机构:
[Zhao, Yunlin; Xu, Zhenggang; Peng, Jiao] Cent South Univ Forestry & Technol, Coll Life Sci & Technol, 498 Shaoshan South Rd, Changsha 410004, Hunan, Peoples R China.;[Xu, Zhenggang; Dong, Meng] Hunan City Univ, Coll Chem & Environm Engn, 518 Yingbin Rd, Yiyang 413000, Hunan, Peoples R China.;[Ge, Yu] Hubei Univ Nationalities, Coll Forestry, 39 Xueyuan Rd, Enshi 445000, Hubei, Peoples R China.;[Yang, Guiyan] Northwest A&F Univ, Coll Forestry, Lab Walnut Res Ctr, Yangling 712100, Shaanxi, Peoples R China.
通讯机构:
[Yang, Guiyan] N;Northwest A&F Univ, Coll Forestry, Lab Walnut Res Ctr, Yangling 712100, Shaanxi, Peoples R China.
关键词:
Juglans regia;Osmotic tolerance;ROS scavenger;V-ATPase G subunit
摘要:
JrVHAG1 is an important candidate gene for plant osmotic tolerance regulation. Vacuolar H+-ATPase (V-ATPase) is important for plant responses to abiotic stress; the G subunit is a vital part of V-ATPase. In this study, a G subunit of V-ATPase was cloned from Juglans regia (JrVHAG1) and functionally characterized. JrVHAG1 transcription was induced by mannitol that increasing 17.88-fold in the root at 12 h and 19.16-fold in the leaf at 96 h compared to that under control conditions. JrVHAG1 was overexpressed in Arabidopsis and three lines (G2, G6, and G9) with highest expression levels were selected for analysis. The results showed that under normal conditions, the transgenic and wild-type (WT) plants displayed similar germination, biomass accumulation, reactive oxygen species (ROS) level, and physiological index. However, when treated with mannitol, the fresh weight, root length, water-holding ability, and V-ATPase, superoxide dismutase, and peroxidase activity of G2, G6, and G9 were significantly higher than those of WT. In contrast, the ROS and cell damage levels of the transgenic seedlings were lower than those of WT. Furthermore, the transcription levels of V-ATPase subunits, ABF, DREB, and NAC transcription factors (TFs), all of which are factors of ABA signaling pathway, were much higher in JrVHAG1 transgenic plants than those in WT. The positive induction of JrVHAG1 gene under abscisic acid (ABA) treatments in root and leaf tissues indicates that overexpression of JrVHAG1 improves plant tolerance to osmotic stress relating to the ABA signaling pathway, which is transcriptionally activated by ABF, DREB, and NAC TFs, and correlated to ROS scavenging and V-ATPase activity.
摘要:
A turn-on fluorescent probe Coumarin-SO2 based on a nucleophilic addition reaction was developed for the rapid detection of SO32- in aqueous media. The probe Coumarin-SO2 displays excellent water solubility, fast response, highly sensitivity and highly selectivity over other biological related species. More importantly, living cell imaging experiments indicate the feasibility of using the probe for the detection of SO32- in biological systems. Copyright (c) 2015 John Wiley & Sons, Ltd.
关键词:
BiOBr/BiOI;fly-ash cenospheres;photocatalytic activity;pH value
摘要:
A series of BiOBr/BiOI photocatalysts supported on fly-ash cenospheres (FACs) were successfully prepared via a facile one-pot alcoholysis method. The as-prepared samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectrometer (XPS) and UV-visible diffuse reflectance spectroscopy (DRS). The results indicate that pH value plays a critical role in BiOBr/BiOI loading. Based on the photodegradation tests under visible light irradiation (blue LED irradiation), the photocatalytic property of BiOBr/BiOI/FACs photocatalysts obtained under alkaline conditions is superior to that prepared under neutral or acidic conditions, and higher than those of BiOB/FACs and BiOI//FACs. The improved photocatalytic performance of BiOBr/BiOI/FACs can be attributed to more BiOBr/BiOI loaded on the surface of FACs and the efficient photogenerated electron-hole separation.
摘要:
Natural product tea saponin (TS), extracted from the nutshell of camellia (Camellia oleifera Abel, Theaceae), was introduced into intumescent flame retardant formulations as blowing agent and carbon source. The formulations of the flame retardant system were optimized to get the optimum proportion of TS, and intumescent flame retardant coatings containing tea saponin (TS-IFRCs) were then prepared. It was found that TS can significantly affect the combustion behavior and the thermal stability of TS-IFRCs evaluated by cone calorimetry and simultaneous thermal analyzer, respectively. It was shown that TS, degraded to water vapor and carbon at high temperatures, can combine with other components to form a well-developed char layer. The char layer was supposed to inhibit erosion upon exposure to heat and oxygen and enhance the flame retardancy of TS-IFRCs. In addition, the smoke release of TS-IFRCs was also studied, which provided a low amount of smoke production.
作者机构:
[Liu, Hao; Sun, Jianliang; Wu, Xing] S China Univ Technol, State Key Lab Pulp & Paper Engn, Guangzhou 510640, Guangdong, Peoples R China.;[Zhou, Pandeng] Hunan City Univ, Sch Chem & Environm Engn, Yiyang 413000, Peoples R China.;[Chen, Shicheng] Michigan State Univ, Dept Microbiol & Mol Genet, E Lansing, MI 48824 USA.
通讯机构:
[Liu, Hao] S;S China Univ Technol, State Key Lab Pulp & Paper Engn, Guangzhou 510640, Guangdong, Peoples R China.
摘要:
The biosynthetic utilization of laccase/mediator system is problematic because the use of organic cosolvent causes significant inhibition of laccase activity. This work explored how the organic cosolvent impacts on the laccase catalytic capacity towards 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) in aqueous solution. Effects of acetone on the kinetic constants of laccase were determined and the results showed K<sub>m</sub> and V<sub>max</sub> varied exponentially with increasing acetone content. Acetone as well as some other cosolvents could transform ABTS radicals into its reductive form. The content of acetone in media significantly affected the radical scavenging rates. Up to 95% of the oxidized ABTS was successfully recovered in 80% (v/v) acetone in 60 min. This allows ABTS recycles at least six times with 70%–75% of active radicals recovered after each cycle. This solvent-based recovery strategy may help improve the economic feasibility of laccase/ABTS system in biosynthesis. View Full-Text
摘要:
Objective To investigate the flexibility and mobility of the Bacillus thuringiensis toxin Cry1 Aa. Methods The graph theory-based program Constraint Network Analysis and normal mode-based program NMsim were used to analyze the global and local flexibility indices as well as the fluctuation of individual residues in detail. Results The decrease in Cry1 Aa network rigidity with the increase of temperature was evident. Two phase transition points in which the Cry1 Aa structure lost rigidity during the thermal simulation were identified. Two rigid clusters were found in domains I and II. Weak spots were found in C-terminal domain III. Several flexible regions were found in all three domains; the largest residue fluctuation was present in the apical loop2 of domain II. Conclusion Although several flexible regions could be found in all the three domains, the most flexible regions were in the apical loops of domain II.
摘要:
In this work, we propose a method for constructing silver nanoparticles (AgNPs) on mesoporous silica nanospheres (MSNs) by a DNA-templated process. By in situ formation, the gatekeeper can be easily modulated to meet different degrees of glutathione (GSH) stimuli for location-specific drug release.