Energies
·
2020
·Vol. 13
·期 23
·6202
·
IF 2.702
Xuyan Song,Min Wei,Qiang Gao,Xi Pan,Junpeng Yang,Fan Wu,Hongyun Hu
The condensation-collection and quantitative analysis of bio-oil limit its component investigation and utilization. In order to find a convenient method for the analysis of bio-oil, the present study conducted an attempt for bio-oil quantitative analysis with the addition of internal standards before pyrolysis. Based on their good thermal stability, phenethyl acetate and naphthalene were selected as standards in the study and experiments were carried out to compare the effects of two added modes (adding into the biowaste before pyrolysis or adding into bio-oil after pyrolysis) on the bio-oil analysis. The results showed that both phenethyl acetate and naphthalene were mainly volatilized under testing conditions, which could be transferred into the oil with the volatile matters during biowaste pyrolysis. Through the co-pyrolysis experiments of the internal standards with lignin and cellulose, almost no interactions were found between the internal standards and such components. Furthermore, adding these standards before pyrolysis hardly affected the properties of noncondensable gas and biochar from the used biowaste samples (tobacco and sawdust waste). Compared with the bio-oil analysis results via traditional methods by adding standards into the bio-oil after pyrolysis, the results regarding the component distribution characteristics of the bio-oil were similar using the proposed method through the addition of standards before pyrolysis. Considering adequate mixing of the added standards (before pyrolysis) in the generated bio-oil, the proposed method could partly help to avoid inaccurate analysis of bio-oil components caused by incomplete collection of the pyrolytic volatiles.Keywords:biowaste;pyrolysis;bio-oil quantitative analysis;phenethyl acetate;naphthalene
研究领域:
能源与环境科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MOLECULAR STRUCTURE
·
2021
·
IF 3.196
Simin Liu,Defei Yin,Wei Li,Dongzhi Liu,Xueqin Zhou
In this paper, three new compounds were synthesized by introduction of benzyloxy group to phenylethyl phenylacetate ( PPA ) and shorting the flexible ester linker. NMR spectra and mass spectra are achieved to confirm the structure of the compounds. The solid-liquid and liquid-solid phase change behaviors of PPA and these three compounds were explored by direct observation and differential scanning calorimetry (DSC) measurements. It was found that all four compounds would form supercooled liquids during a heating-cooling cycle. The supercooling degree is as large as 44 °C or above. The effects of benzyloxy group and the flexible linker on the phase transition processes as well as the supercooling degrees were discussed in detail with the computational optimized geometry of isolated molecules. It was revealed that the dihedral angles between adjacent phenyl rings play a significant role in tuning their phase transition temperatures. This work also discovers the high enthalpies of PPA derivatives and analogues in both solid-liquid and liquid-solid phase transition processes, making them great potentials for the thermal energy control of appropriate working temperature regions.
研究领域:
材料科学
·
物理化学
✓ 已验证
DOI
高影响因子
CHINESE JOURNAL OF CHEMISTRY
·
2013
·Vol. 31
·期 4
·494-500
·
IF 0.917
Chengbiao Yang,Huaimin Wang,Dongxia Li,Ling Wang
The development of molecular hydrogels that can be applied for mimicking bioactive molecules attracts extensive interests of researchers in fields of self-assembly. In this study, we reported on several molecular hydrogels based on naphthylacetic acid-peptides containing L -histidine formed by the heating-cooling process. All hydrogels exhibited higher activity to hydrolyze 4-nitrophenyl acetate (4-NPA) than the free L -histidine probably due the high density of L -histidine residue at the surface of self-assembled nanofibers. To calculate the 4-NPA hydrolysis rates, the Michaelis-Menten enzyme kinetics model was made. Among these gels, the gel of Nap-GFFYGHY possesses the highest enzyme activity of making the ester bond cleavage, which is approximately 25 times higher than that of the control (free L -histidine and Nap-GFFYGYY). These results indicate that molecular hydrogels with self-assembled nanofibers have great potential for the generation of self-assembled multivalent materials.
研究领域:
生物化学
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材料科学
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DOI
高影响因子
Nanoscale
·
2019
·Vol. 11
·期 13
·5960-5966
·
IF 6.97
Jinxing Chen,Liang Huang,Qingqing Wang,Weiwei Wu,He Zhang,Youxing Fang,Shaojun Dong
Nanozymes provide comparative advantages over natural enzymes and conventional artificial enzymes for catalytic reactions. However, nanozymes are only suitable for limited types of reactions, whose catalytic principles are not yet fully revealed. Herein, a new nanozyme based on a bionic zeolitic imidazolate framework is proposed. Zeolitic imidazolate framework-8 (ZIF-8) possesses a similar geometric structure to that of the active center of human carbonic anhydrase II (hCAII) and exhibits catalytic performance analogous to that of the hCAII. The less imidazolate coordinated zinc cations on the external surface of ZIF-8 can act as Lewis acid sites, lowering the pKa of Zn-bound H2O molecules from 14 to 8.4, which facilitates the deprotonation of H2O molecules and generation of zinc-bound hydroxide nucleophiles. The esterase-like ZIF-8 nanozyme shows a similar affinity to p-nitrophenyl acetate compared with hCAII. The ZIF-8 nanozyme also promotes CO2 hydration and acetylthiocholine hydrolysis reaction, and a series of ZIFs are also found with intrinsic enzyme-like activities due to similar compositions and spatial structures. These results imply that the bionic nanoparticles can be developed to fabricate a new generation of nanozymes by mimicking the active sites of natural enzymes.
研究领域:
催化
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材料科学
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生物化学
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纳米技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ANALYTICAL BIOCHEMISTRY
·
2022
·
IF 3.191
Guo-Ying Chen,Xi Zhou,Tao Tian,Chun-Yan Zhang,Shi-Jun Yin,Hua Chen,Yi Xu,Feng-Qing Yang
A simple and time-saving colorimetric method was developed to quantify sulfonamides (SAAs) in milk via inhibition of the human carbonic anhydrase II (hCAII)-like activity of ZIF-8 that can hydrolyze p -nitrophenyl acetate ( p NPA) to p -nitrophenol ( p NP), following the color change from yellow to colorless. Effects of different reaction conditions, including pH, temperature, amount of ZIF-8, and incubation time , were investigated. The value of Michaelis-Menten constant ( K m ) is measured to be 0.15 mM, which exhibits high affinity to p NPA. The IC 50 (0.17, 0.24, and 0.60 mM) and inhibition constant ( K i ) (0.09, 0.13, and 0.33 mM) of sulfamethazine (SD), sulfadimethoxine (SDM), and sulfathiazole (ST) on ZIF-8 were measured, respectively. Moreover, the activity of ZIF-8 remains more than 90.0% of its initial activity after 30 days’ storage. The colorimetric method for SD, SDM, and ST determination was established at the linear ranges of 6.3–750.0 μM (1.75–208.75 mg/kg), 6.3–750.0 μM (1.96–232.75 mg/kg), and 5.0–1250.0 μM (1.28–319.15 mg/kg) with limit of detection of 4.3, 3.2, and 3.9 μΜ (1.2, 0.99, and 0.96 mg/kg), respectively. In addition, the spiked recoveries of SAAs in milk sample are in the range of 81.6%–106.7% with RSD less than 6.5%. In short, the developed colorimetric method can achieve rapid analysis of SAAs in milk with simple operations.
研究领域:
分析化学
·
食品科学
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材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2019
·Vol. 43
·期 43
·16981-16989
·
IF 3.069
Bingying Jia,Miaojiang Wu,Hua Zhang,Yi Zeng,Gongying Wang
Titanates are frequently used as precursors to prepare transesterification catalysts with TiIV species. Unfortunately, it is challenging to control the dispersity of TiIV active sites on supports. Herein, a series of TiIV species is anchored on abundant linker vacancy sites by introducing point and large scale defects in UiO-66(Zr/Ti) with hierarchical-pore structure. The catalyst functionalized by titanium(IV) oxide bis(2,4-pentanedionate) shows excellent catalytic performance in the transesterification of dimethyl carbonate with phenyl acetate. The catalysts are characterized by XRD, FT-IR, N2 adsorption–desorption, XPS, SEM and STEM-HAADF techniques. The results demonstrate that the delicate mesopores in the support can not only exhibit a large surface area for the distribution of the active sites, but also provide better mass transfer performance. Meanwhile, the introduction of octahedral TiIV ions raises the activity of the catalyst via more coordinatively unsaturated ZrIV sites. Furthermore, using titanium(IV) oxide bis(2,4-pentanedionate) as a Ti source can effectively prevent the condensation of tetrahedral TiIV species anchored on the hierarchical-pore UiO-66(Zr/Ti) support.
研究领域:
催化
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材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
PROCESS BIOCHEMISTRY
·
2023
·
IF 4.4
Xiaoliang Wang,Yibo Li,Yan Liu,Qian Wu,Zunxi Huang,Shukun Tang,Junmei Ding
The newly semi-synthetic β -lactam antibiotics play critical roles in prevention and treatment of β -lactam antibiotic-resistant bacteria. Acetyl xylan esterases belong to carbohydrate esterase 7 family can specifically hydrolyze 7-aminocephalosporanic acid (7-ACA) to produce deacetyl-7-aminocephalosporanic acid (D-7ACA) which is one of the most important starting materials to synthesize newly semi-synthetic β -lactam antibiotics. Here, an effective acetyl xylan esterase, ThAXE, from Thermobifida halotolerans YIM 90462 T , was firstly identified and characterized. ThAXE exhibited its highest catalytic activity against p -nitrophenyl acetate ( p -NPC 2 ) at pH 8.5 and 50 °C, with K m and K cat / K m were 1.0 ± 0.1 mM and 2262.9 mM −1 s −1 , respectively. Additionally, ThAXE can hydrolyze the acetyl group of 7-ACA at its C3' position with the specific activity of 7.4 U mg −1 . Furthermore, molecular docking combined with site-directed mutagenesis validation demonstrated that the pocket of catalytic residues Ser186, Asp272, and His301 could accommodate p -NPC 2 and 7-ACA ligands. This is the first report of a novel acetyl xylan esterase from T. halotolerans that has considerable potential biotechnological values.
研究领域:
生物化学
·
微生物学
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生物技术
·
酶学
✓ 已验证
产品关联
DOI
高影响因子
FOOD CHEMISTRY
·
2022
·
IF 9.231
Wenhui Duan,Qijie Guan,Hui-Ling Zhang,Fang-Zhou Wang,Ran Lu,De-Mao Li,Yan Geng,Zheng-Hong Xu
Lactic acid bacteria (LAB) have exhibited strain/species specificity for different food matrices. We investigated the impact of LAB fermentation on the flavor, chemical profile, and bioactivity of goji juice. The colony counts of five selected strains reached above 8.5 log CFU/mL. The fermentation increased the organic acids, decreased the sugars, and improved the sensory quality of goji juice. The majority of the strains had increased acetic acid, heptanoic acid, ethyl phenylacetate, and linalool levels. Specific strains suppressed α-glucosidase and pancreatic lipase activities and increased the antioxidant activities of fermented goji juice. Based on non-targeted metabolomics and activities, 23 important differential metabolites were screened among 453 metabolites. The quantification results showed that isoquercitrin and m -coumaric content varied among strains, reflecting the strain specificity in flavone and flavonol biosynthesis and phenylalanine, tyrosine, and tryptophan biosynthesis. These findings will provide useful information for fermented goji juice biochemistry research.
研究领域:
食品科学
·
微生物学
·
生物化学
·
营养学
✓ 已验证
DOI
PubMed
高影响因子
Foods
·
2024
·Vol. 13
·期 17
·2653
·
IF 4.7
Zhiwei Hou,Ziyue Chen,Le Li,Hongping Chen,Huiyuan Zhang,Sitong Liu,Ran Zhang,Qiyue Song,Yuxuan Chen,Zhucheng Su,Liying Xu
Scented green tea (Camellia sinensis) is a type of reprocessed green tea produced by scenting with flowers. To investigate the differences in the volatiles of scented green tea processed with four different flowers (Jasminum sambac,Osmanthus fragrans,Michelia alba, andRosa rugosa), gas chromatography–ion mobility spectrometry (GC–IMS) and gas chromatography–mass spectrometry (GC–MS) were employed to detect and identify the volatile compounds in the four types of scented teas. GC–IMS and GC–MS identified 108 and 101 volatile compounds, respectively. The key characteristic volatile compounds, namely indole, linalool,β-myrcene, benzyl acetate, and ethyl benzoate (jasmine tea); cedrol, (E)-β-ionone,γ-decalactone, and dihydro-β-ionol (osmanthus tea); geraniol, phenylethyl alcohol, jasmone, methyl jasmonate, hexadecanoic acid, 4-ethyl-benzaldehyde, 2-methylbutyl hexanoate, and indole (michelia tea); and 3,5-dimethoxytoluene, (E)-β-ionone, and 2-methylbutyl hexanoate (rose tea), were identified through chemometric analysis combined with relative odor activity values (ROAVs) and sensory evaluation. This study provides new insights into the formation of aroma molecular fingerprints during green tea scenting with flowers, providing theoretical guidance for infusing distinct aroma characteristics into green tea during scented tea processing.
研究领域:
食品科学
·
分析化学
·
农学
·
植物科学
✓ 已验证
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）