INTERNATIONAL BIODETERIORATION & BIODEGRADATION
·
2016
·
IF 2.429
Jinwei Zhang,Zhangwei Han,Bo Teng,Wuyong Chen
For getting a clear and detail process of chromium tanned leather biodeteriorated with Penicillium sp. as a reference for future research and providing a cleaner chromium containing leather waste disposal method. The chromium tanned leather (CTL) and chromium tanned hide powder (CTHP) were biodeteriorated with the Penicillium . The CTL was biodeteriorated at first to verify the biodeterioration effect, and then the changes of the CTHP structure and thermal properties after the biodeterioration were analyzed by Scanning Electron Microscope (SEM), Fourier transform infrared spectroscopy (FT-IR), Thermal Gravimetric Analyzer (TG) and Differential Scanning Calorimeter (DSC). The deterioration degree of the CTHP was characterized by the contents of hydroxyproline and total nitrogen in the filtrate, the Penicillium number was counted too during the process. The results showed that the CTL could be biodeteriorated with the Penicillium as shrinkage temperature and mass decreasing even though the biodeterioration degree was not ideal enough. After the process of CTHP biodeteriorated with the Penicillium , the surface morphology and structure of the CTHP were damaged. The thermal resistance and thermal denaturing temperature reduced which showed the detanning effect happened in the biodeterioration process. With the increasing of biodeterioration time, the hydroxyproline and total nitrogen in the filtrate increased. The Penicillium number maximized at 96 h and protease was produced in the process with enzymatic activity reaching to 9.23U mL −1 . These phenomena demonstrated the Penicillium grew through digesting chromium tanned leather and produced metabolites. To sum up, the biodeterioration process of chromium tanned leather with Penicillium was a synergistic effect of chromium detanning and the Penicillium growth.
研究领域:
微生物学
·
环境科学
·
皮革化学
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF FOOD PROPERTIES
·
2018
·
IF 1.845
Zhibing Wu,Fengwen Huang,Yutao Chen,Hong Xu,Manjunath D. Meti,Yu Fan,Qingguo G. Han,Haifeng Tang,Zhendan He,Zhangli Hu
The interaction of trypsin with acteoside was studied using ultraviolet visible absorption, fluorescence, synchronous fluorescence, circular dichroism techniques, along with molecular docking method. The fluorescence experiments indicated that acteoside quenched the intrinsic fluorescence of trypsin via a combined quenching process (static and dynamic quenching). The binding constant of acteoside to trypsin obtained was 2.50 × 105 L mol−1 at 298 K and the number of binding site was about one under the same experimental condition. The thermodynamic functions ΔH° and ΔS° of the binding process were 8.79 kJ mol−1 and 132.58 J mol−1 K−1, respectively, which indicated that the hydrophobic force was the main acting force between them. Ultraviolet–visible, synchronous fluorescence together with circular dichroism spectra studies demonstrated that the interaction of acteoside with trypsin lead to a loosening and unfolding of the protein backbone with partial β-sheet structures being transformed into α-helix structures. All these experimental results were validated and explained reasonably by docking studies. And the molecular docking results further illustrated that besides hydrophobic forces, hydrogen bonds also played an important role in the stabilization of the acteoside–trypsin complex. Results from this study should be helpful to make full use of acteoside in the food industry and be useful to the design of the drugs for the diseases related to trypsin.
研究领域:
生物化学
·
药物设计
·
食品科学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY
·
2021
·Vol. 193
·期 7
·2225-2244
·
IF 2.926
Wan Yin,Fan Haowei,Gao Lin,Li Ruyi,Xie Mingyong,Wu ChouFei,Chen Longyan,Fu Guiming
Tannase from Aspergillus niger NL112 was purified 5.1-fold with a yield of 50.44% via ultrafiltration, DEAE-Sepharose Fast Flow column chromatography, and Sephadex G-100 column chromatography. The molecular weight of the purified tannase was estimated as 45 kDa. The optimum temperature and pH for its activity were 45 °C and 5.0, respectively. The results of circular dichroism, FT-IR (Fourier transform infrared) spectroscopy, and fluorescence spectra indicated that high temperature could lead to the change of tannase secondary and tertiary structures. Tannase had a greater affinity for tannic acid at 40 °C with a K m value of 2.12 mM and the greatest efficiency hydrolysis ( K cat / K m ) at 45 °C. The rate of inactivation ( k ) increased with the increase of temperature and the half-life ( t 1/2 ) gradually decreased. It was found to be 1.0 of the temperature quotient ( Q 10 ) value for tannic acid hydrolysis by tannase. The thermodynamic parameters of the interaction system were calculated at various temperatures. The positive enthalpy ( ΔH ) values and decreasing ΔH values with the increase of temperature indicated that the hydrolysis of tannase was an endothermic process. Our results indicated that elevated temperature could change the tertiary structure of tannase and reduce its thermostability, which caused a gradual decrease of tannase activity with an increase in temperature.
研究领域:
生物化学
·
微生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
PETROLEUM CHEMISTRY
·
2024
·Vol. 64
·期 3
·346-356
·
IF 1.3
Wei Shengchao,Lu Dan,Yao Zhilin,Zhu Lijun,Yin Changlong,Xia Daohong
Abstract In order to understand the structure of asphaltene after its disaggregating by chemical processing, a comprehensive study for exploring the structural changes of asphaltene after acylation as a case of chemical processing was conducted. Functional groups, crystal parameters, hydrogen types, and micromorphology of acylated asphaltenes were analyzed by FT-IR, XPS, XRD, 1 H NMR, SEM and IFM (inverted fluorescence microscope) methods. Additionally, fluorescence spectroscopy methods were performed to analyze the effect of acylation on the aggregation ability of asphaltene. Experimental results indicated that the C=O double bond was enhanced and the content of O–C=O was increased on the surface of acylated asphaltene. The number of stacking layers and the aggregate size of asphaltene decreased obviously after acylation. Fluorescence spectral analysis showed that the critical aggregation concentration of acylated asphaltenes increased compared to the raw asphaltenes. These results indicate that acylation reaction can disaggregate asphaltenes and hinder their re-aggregation in a solution. The disaggregation effect of asphaltene acylation can be attributed to the weakening of a hydrogen bonding and enhancement of a steric hindrance in the asphaltene molecule. This study provided the further understanding of the structural changes of asphaltene after the chemical treatment.
研究领域:
石油化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE
·
2024
·
IF 3.3
Qihong Zhang,Xinyu Lin,Weike Su
BACKGROUND In this study, the content and structure of Polygonatum sibiricum polysaccharides and saponins during different processing stages were determined. RESULTS After processing of Polygonatum , the content of polysaccharide and glucose decreased, and the content of galactose, glucuronic acid and sugar substitution gradually increased. The content of total saponins increased significantly. Only 18 compounds were found in raw Polygonatum and 17 new compounds were presented in processed Polygonatum . During the processing of Polygonatum , the polysaccharide was partially degraded into oligosaccharides, the molecular weight gradually decreased, and the neutral sugar was converted into uronic acid, resulting in a decrease in polysaccharide content. The saponins were partially degraded into sapogenins or modified. CONCLUSION This study clarifies the changes in the content and structure of polysaccharides and saponins in processed Polygonatum , which will pave the way for elucidating the processing mechanism. © 2024 Society of Chemical Industry.
研究领域:
药用植物学
·
植物化学
·
中药学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
LWT-FOOD SCIENCE AND TECHNOLOGY
·
2021
·
IF 4.952
Haihua Jiang,Xing Hu,Junhui Pan,Deming Gong,Guowen Zhang
This research aimed to investigate the changes in the structure and functional properties of glutenin (Glu) induced by hesperetin (Ht) or hesperidin (Hd). Both Ht and Hd quenched the fluorescence of Glu through a static process and formed a Ht/Hd–Glu complex in one binding site. The binding constants between Glu and Ht and Hd were 4.20 × 10 4 L mol −1 and 3.59 × 10 4 L mol −1 at 25 °C, respectively. The computer simulations showed their bindings were dominated by hydrogen bonds and hydrophobic forces, and also provided the changes in particle motion and macroscopic properties of Glu induced by Ht/Hd. The presence of Ht/Hd promoted the exchange of sulfhydryl and disulfide bonds, resulting in the structural changes of Glu and the free sulfhydryl groups more exposed. Meanwhile, the increase in β-sheet content of Glu might cause the contraction of the carbon chain, thereby increasing the surface hydrophobicity. Due to the increase in rigid clusters and the decrease in flexibility, thermal stability of Glu was enhanced. Moreover, the emulsifying activity of Glu was significantly improved. This research lays the foundation for the application of Ht/Hd and Glu in healthy food or the optimization of Glu-based products.
研究领域:
食品科学
·
生物化学
✓ 已验证
产品关联
DOI
高影响因子
Foods
·
2024
·Vol. 13
·期 24
·4183
·
IF 4.7
Rourou Wen,Xianghua Chai,Pingping Wang,Kegang Wu,Xuejuan Duan,Jiasi Chen,Tong Zhang,Liya Zeng
Tea polyphenols have been reported to decrease the rate of starch hydrolysis by inhibiting α-glucosidase. However, the effect of the tea harvesting season and the structure of catechin monomers on the inhibitory activity of α-glucosidase is not understood. In this study, the inhibitory effect and underlying mechanism of four seasons of Dancong tea against α-glucosidase were investigated by in vivo and in vitro experiments, multi-spectroscope and molecular dynamic. The Dancong tea harvested in spring and winter showed a stronger inhibitory effect on α-glucosidase due to a higher content of catechin, especially EGCG ((-)-epigallocatechin-3-gallate). The results of in vivo and in vitro experiments showed that EGCG and ECG ((-)-epicatechin-3-gallate) with a higher content of gallate and hydroxyl groups exhibited a stronger inhibitory effect on starch hydrolysis, rise of postprandial blood glucose and activities of α-glucosidase compared to EGC ((-)-epigallocatechin) and EC ((-)-epicatechin). These gallate and hydroxy groups were more effective in interacting with the amino acid residues in the active site of α-glucosidase, leading to structural changes in the enzyme. Certainly, the inhibitory effect of Dancong tea on α-glucosidase explains one of the mechanisms by which it helps alleviate diabetes; the other hypoglycaemic mechanisms of Dancong tea will be further explored.
研究领域:
食品科学
·
生物化学
·
药理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
GREEN CHEMISTRY
·
2016
·Vol. 18
·期 11
·3370-3377
·
IF 8.506
Wenjing Yang,Haiyang Cheng,Bin Zhang,Yan Li,Tong Liu,Mingli Lan,Yancun Yu,Chao Zhang,Weiwei Lin,Shin-ichiro Fujita,Masahiko Arai,Fengyu Zhao
The hydrogenation of levulinic acid (LA) to γ-valerolactone (GVL) was studied with a homogeneous RuCl2(PPh3)3 catalyst in supercritical CO2 (scCO2). The conversion of LA was observed to increase with CO2 pressure and the possible reasons for this rate acceleration were discussed, including the molecular interactions of CO2 with the reacting and catalytic species as well as the acidity and phase behavior of the reaction mixture. The interaction between CO2 and RuCl2(PPh3)3 was significant, which resulted in the production of an active RuHCl(CO)(PPh3)3 complex and thus enhanced the rate of hydrogenation in the presence of CO2.
研究领域:
化学工程
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Physical Chemistry C
·
2022
·
IF 4.177
Jun Han,Qunfei Zheng,Cheng Jin,Shanmin Wang,Ying Liu,Yusheng Zhao,Jinlong Zhu
The comparison of different stereoisomeric organic compounds under high pressure has been less investigated. Here, we chose different stereochemical configurations of cis/trans-stilbene to study the luminescence properties, polymerization reaction, and structural changes at 0–20 GPa by spectroscopy and XRD. No fluorescence enhancement occurred in cis-stilbene due to π–π stacking. At 16 GPa, the IR, UV–vis, and sample color changes show that it undergoes an irreversible polymerization, that C(sp2)–H changes to C(sp2 + sp3)–H. However, trans-stilbene undergoes fluorescence enhancement at 0–4 GPa due to the reduction of the torsion angle of the benzene ring and the C═C bond leading to the formation of rigid planar molecules, which is further confirmed by the IR and XRD results. At 8 GPa, the new peaks in UV–vis and XRD results show the formation of new substances by structural change. However, the structure of trans-stilbene is more stable, which leads to the return to the raw state after releasing the pressure, and a reversible transformation occurs at high pressure. The cis-trans isomerization under high pressure was also briefly investigated by combining heating and laser irradiation. The cis → trans-stilbene transition can only happen under a fixed-range light irradiation, and the trans → cis-stilbene transition could not happen even under irradiation with a 360 nm laser, which may provide a new idea for synthesizing trans isomers with a higher purity.
研究领域:
化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2025
·
IF 8.5
Pin Gong,Shan Yue,Jie Wang,Ke Xu,Wenjuan Yang,Nan Li,Jing Wang,Yanni Zhao,Fuxin Chen,Yuxi Guo
This study investigates the effects of ultrasound synergistic pH shift modification on the structural and functional properties of Hericium erinaceus (HE) proteins. The modification resulted in significant changes in the molecular structure of HE proteins, including increased solubility (49.69 % at pH 1.5 and 61.30 % at pH 12.5), enhanced surface hydrophobicity (from 721.00 to 3377.00), and the exposure of free sulfhydryl groups, which rose from 9.3 μmol/g in the control to 19.9 μmol/g at pH 12.5. The modification also led to a reduction in particle size, improving oil-holding capacity and foaming properties, with foaming stability increasing from 10.5 % to 60.3 % at pH 12.5. Furthermore, the emulsification activity was significantly enhanced (187.5 % at pH 12.5). Rheological analysis revealed that ultrasound-modified proteins exhibited improved flow stress and gelation properties, with a shear recovery rate of 65.71 %. In 3D printing applications, the modified HE proteins demonstrated better printability, structural stability, and mechanical integrity, attributed to the enhanced molecular interaction and gelation properties. These findings suggest that ultrasound-assisted pH shift modification effectively alters the structure and functionality of HE proteins, making them suitable for use as a versatile raw material in food applications, particularly in 3D food printing.
研究领域:
食品科学
·
生物化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Biobased Materials and Bioenergy
·
2014
·Vol. 8
·期 1
·13-20
·
IF 0.586
Zhang Junhua,Lin Lu
In this study, extremely low acid (ELA, 0.08% w/v of sulfuric acid) was used for the hydrolysis of cornstalk in a reactor at a designed reaction temperature from 130 °C to 170 °C, and the results were compared with hot water hydrolysis and low acid (LA, 0.2% w/v of sulfuric
acid) hydrolysis. And the influences of initial sulfuric acid concentration and reaction temperature on the hydrolysis of cornstalk were discussed in details. It was found that pentose is the most abundant sugar, and 6.4 g/L of xylose and 1.5 g/L of arabinose could be obtained at the temperature
of 160 °C when hydrolysis with ELA, the pentose yield for hemicellulose in cornstalk was 68.7%. Furthermore, the physicochemical and structural changes for the hydrolyzed and controlled cornstalk were characterized by Fourier Transform Infrared Spectroscopy (FTIR), X-ray diffraction (XRD)
and Scanning Electron Microscope (SEM), and the results were elaborated in detail.
研究领域:
生物化学
·
材料科学
✓ 已验证
DOI
高影响因子
Journal of Biobased Materials and Bioenergy
·
2020
·Vol. 14
·期 1
·20-28
·
IF 1.126
Lei Ming,Luo Bin,Zhang Qingtong,Guo Chenyan,Chi Mingchao,Yun Xiaojing,Min Douyong,Wang Shuangfei
Herein, residual lignin was extracted from unbleached sugarcane bagasse pulp via the sequential enzymatic-weak acid hydrolysis method. Subsequently, chlorine dioxide delignification was applied to the extracted lignin. The structural changes of lignin during chlorine dioxide delignification
were characterized by Fourier transform infrared spectroscopy (FT-IR), 13C-nuclear magnetic resonance (13C NMR), 1H-13C heteronuclear single quantum coherence (2D HSQC), and quantitative 31P-nuclear magnetic resonance (31P-NMR)
spectroscopy. The degradation products of lignin dissolved in the simulated bleaching liquor, extracted, and quantified via gas chromatography-mass spectrometry (GC-MS). Lignin was significantly degraded during the delignification process, showing cleavage of the aromatic ring, removal of
the methoxyl group, and cleavage of major interunit linkages. However, the carboxylic acid content increased and GC-MS analysis indicated that lignin was degraded into several organic substances dissolved in the liquor. However, only a few absorbable organic halides (AOX) were generated, confirming
that chlorine dioxide bleaching is an ideal bleaching method.
研究领域:
植物化学
·
制浆造纸工程
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）