JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
·
2020
·
IF 4.192
Junfeng Feng,Teng Fan,Changyue Ma,Yangyang Xu,Jianchun Jiang,Hui Pan
Levulinate is one of the high added-value biomass-derived chemicals that is primarily produced from hexoses in cellulose and hemicellulose. Producing levulinate from pentoses in hemicellulose that is extensively distributed in biomass is still highly challenging. In this study, biomass materials and carbohydrates (including cellulose, xylan, glucose, fructose, and xylose) were collaboratively converted into levulinates efficiently over various zeolites with ethanol/dimethoxymethane as cosolvents. The key process for converting pentoses into levulinates is the synthesis of intermediates (furfural) into alkoxy methyl furfural via electrophilic substitution or their conversion into furfuryl alcohol via in situ hydrogenation. The substitution was achieved by the synergic effect between bifunctional catalysts and cosolvents, which promotes conversion of furfural into alkoxy methyl furfural via the electrophilic addition of alkoxy methyl radicals. Hydrogenation of furfural into furfuryl alcohol was impelled by the cooperative process between in situ generated H-donor from alcohol solvents and zeolite catalysts. Moreover, a favorable yield of 21.05 mol % of levulinates was achieved by simultaneous and collaborative conversion of cellulose and hemicellulose with the one-pot process using ethanol/dimethoxymethane as a cosolvent and the zeolite with B and L acid sites as a catalyst.
研究领域:
生物化学
·
催化化学
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DOI
高影响因子
Reaction Kinetics Mechanisms and Catalysis
·
2017
·Vol. 122
·期 2
·1031-1047
·
IF 1.264
Meng Chen,Cao Gui-Ping,Yan Yi-Zhen,Zhao En-You,Hou Lin-Yi,Shi Hua-Yi
In this work, during the synthesis and hydrolysis of cellulose acetate propionate (CAP), the research not only focused on the contents, but also the distributions of acetyl and propionyl groups in the different positions of anhydroglucose unit, i.e. C2, C3 and C6. It was investigated that cellulose propionylation was more difficult than acetylation, which required larger amounts of reagents. At the same temperature, the reaction rate constant of cellulose acetylation was much higher than that of propionylation. Furthermore, the partial degrees of propionyl substitution in CAP were 0.54, 0.54, and 0.48 for C2, C3, and C6. The contents of propionyl distributed on C2 and C3 positions were higher than that on C6 indicating that acetyl took the position of C6 preferentially. During the hydrolysis of CAP, the degrees of hydrolysis were 0.1 for acetyl and 0.3 for propionyl. Acetyl groups in the C6 position and propionyls in the C2 position were hydrolyzed much easier with the degrees of hydrolysis of 0.16 and 0.32, respectively. In addition, it has been investigated that hydroxyl groups in the C3 position exhibited the lowest reactivity during the synthesis of CAP, while acyl groups on C3 was also the hardest to be hydrolyzed.
研究领域:
材料科学
·
化学工程
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产品关联
DOI
高影响因子
Food Chemistry-X
·
2022
·
IF 6.443
LI Junxing,Miao Aiqing,ZHAO Gangjun,Liu Xiaoxi,Wu Haibin,Luo Jianning,Gong Hao,Zheng Xiaoming,Deng Liting,Ma Chengying
‘Taro-like’ aroma is a pleasant flavor and value-added trait in pumpkin species imparted by unknown key volatile compounds. In this study, we used the electronic nose (E-nose), gas chromatography-mass spectrometry (GC–MS), and GC-Olfactometry (GC-O) to study the aroma profile, volatile compounds, and key contributors, respectively. By E-nose and GC–MS, we found significant differences in the aroma profiles and volatile compounds between fruits from five samples with/without ‘taro-like’ aroma. According to the analysis of differential volatile compounds obtained from GC–MS and the GC-O analysis of the sample with ‘taro-like’ aroma, we found that 2-acetyl-1-pyrroline representing the ‘taro’ odor was only identified in the sample with ‘taro-like’ aroma. Therefore, we conclude that 2-acetyl-1-pyrroline is the key contributor to the 'taro-like' aroma. Moreover, the relationship between 2-acetyl-1-pyrroline and ‘taro-like’ aroma was further verified via other pumpkin samples. Our results provide a theoretical basis for understanding the aroma characteristics of pumpkin fruit.
研究领域:
植物学
·
食品科学
·
分析化学
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产品关联
DOI
PubMed
高影响因子
CURRENT BIOLOGY
·
2024
·
IF 8.1
Yun Chen,Xia Hua,Siyu Li,Jiamei Zhao,Huan Yu,Dongyao Wang,Jiqiang Yang,Lijun Liu
Rice paddy has been the main source of anthropogenic methane (CH 4 ) emissions, with significant variations among rice varieties. 2-Acetyl-1-pyrroline (2-AP) is the key component of the pleasant aroma in fragrant rice. Here, we show that fragrant rice is metabolically active in nitrogen assimilation and exhibits high levels of 2-AP and that CH 4 fluxes at the booting stage and cumulative emissions are 25.5% and 14.8% lower, respectively, in fragrant rice paddies compared with nonfragrant rice paddies. Three precursors involved in 2-AP synthesis—proline, glutamic acid, and ornithine—are identified as crucial nitrogen compounds that significantly promote CH 4 oxidation in the rhizosphere. Augmenting 2-AP synthesis, either through foliar spraying or by utilizing CRISPR-Cas9 technology to generate knockout lines of BETAINE ALDEHYDE DEHYDROGENASE 2 gene, effectively enhances CH 4 oxidation and reduces CH 4 fluxes. Our findings reveal that the 2-AP metabolic pathway coordinates the carbon/nitrogen cycle to improve nitrogen assimilation along with high 2-AP levels and mitigate CH 4 emissions in paddy ecosystems.
研究领域:
植物学
·
环境科学
·
遗传学
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产品关联
DOI
PubMed
高影响因子
Food Analytical Methods
·
2022
·Vol. 15
·期 9
·2479-2486
·
IF 3.498
Zhang Shengnan,Li Zhibo,Qi Yanxia,Yu Pei,Zhao Qiancheng
The determination of 2-acetyl-1-pyrroline (2-AP), which is an important flavour compound of crustaceans and has a low odour threshold of 0.05 μg/L in water, is still a challenge due to the instability and trace levels of 2-AP in food samples. In this study, 2-AP was trapped by o-phenylenediamine and subsequently purified by the dispersive solid-phase extraction and dispersive liquid–liquid microextraction (DSPE-DLLME) methods for HPLC–UV analysis. The developed method was simple, fast and sensitive for the determination of 2-AP in shrimp. Under the optimized DSPE-DLLME conditions, the developed method exhibited excellent linearity ( R 2 = 0.996) and a low limit of detection (LOD, 1.77 μg/kg) and limit of quantitation (LOQ, 5.33 μg/kg). The recoveries of 2-AP in shrimp ranged from 86.3 to 101.6%. In addition, the developed method was applied to detect 2-AP levels in baked shrimp (ranging from 5.6 to 12.6 μg/kg), indicating that the formation of 2-AP could be observed in thermally treated shrimp depending on heating temperature and time. In summary, the developed method has potential application for the trace determination of 2-AP in shrimp due to its convenience and high sensitivity.
研究领域:
食品科学
·
分析化学
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DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2024
·
IF 7.7
Ju Liu,Danna Yan,Qianying Chen,Huayong Peng,Lu Jin,Chong Feng,Lixia Zhang,Guomin Zhao,Depo Yang,Zhimin Zhao
In this study, a homogeneous polysaccharide, named YDOP-1 was isolated form Dendrobium officinale using hot water extraction and ethanol precipitation method. YDOP-1 was characterized to be a typical O -acetyl-glucomannan with the molecular wight was 13,456 Da. Cell viability and colony forming assay showed that YDOP-1 possess moderate anti-gastric cancer effects. In order to further improve the anti-gastric cancer effects of YDOP-1, a selenium modification on YDOP-1 was performed. Energy dispersive spectrometer (EDS) and X-ray photoelectron spectroscopy (XPS) analysis demonstrated that the Se was successfully introduced into YDOP-1 by forming Se O bonds. Se modification significantly enhanced the anti-gastric cancer effects of YDOP-1, which could effectively inhibit the proliferation of MGC-803 cells via suppressing colony and inducing apoptosis by regulating the apoptosis proteins of Bax, Bcl-2, and Caspase-7. Our results indicated that the Se modified O -acetyl-glucomannan, YDOP-Se, was expected to be useful in the biomedicine field for the gastric cancer treatment.
研究领域:
药用植物学
·
肿瘤生物学
·
生物医学工程
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产品关联
DOI
PubMed
高影响因子
CARBOHYDRATE POLYMERS
·
2019
·
IF 6.044
Fu Li,Pengfei Fei,Bowen Cheng,Jianqiang Meng,Liang Liao
In order to improve the antibacterial efficiency and spectrum of cellulose acetate reverse osmosis membrane (CA–RO), both quaternary ammonium and bromoacetyl groups were introduced into cellulose diacetate under mild conditions forming CA–RO with bi-antibacterial groups for seawater desalination. Bromoacetyl bromide and a series of tertiary amine were chosen as the modification agents respectively. The characterization results showed that both two antibacterial groups were successfully introduced with a certain density. The obtaining membrane had a less hydrophilic but more electronegative surface as well as improved mechanical property. The flux values increased firstly and decreased subsequently after twice modifications while the salt rejection rose. The membrane modified with N,N- dimethyloctylamine (DMOA) had the optimal comprehensive performance of flux and salt rejection. The antibacterial testing results indicated that the resulting RO membranes showed high antibacterial efficiency and broad-spectrum. Their bactericidal rates against gram-negative Escherichia coli ( E. coli ) and gram-positive Staphylococcus aureus ( S. aureus ) were more than 99.9%.
研究领域:
材料科学
·
环境工程
·
生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Journal of Materials Research and Technology-JMR&T
·
2020
·
IF 5.289
Weiming Wang,Meng Xu,Jiahao Lou,Aixue Dong
Tetraacetylethylenediamine (TAED) activated hydrogen peroxide (H 2 O 2 ) was tentatively used in the bleaching of scoured jute fibers, and the effects of this method on the physicomechanical properties, main chemical compositions, and structures during bleaching were evaluated and compared with conventional H 2 O 2 bleaching. By comparing with H 2 O 2 bleached jute fibers, the TAED-activated H 2 O 2 bleached jute fibers were found to have a better storage stability of whiteness and yellowness, higher breaking tenacity, lower fineness value and breaking extension. The differences in morphological structure and thermogravimetric analysis showed that the TAED-activated H 2 O 2 bleaching system had a stronger ability for the removal of noncellulosic materials than conventional H 2 O 2 bleaching system. The changes in main chemical compositions and Fourier transform infrared spectra further indicated that the removal ability of TAED-activated bleaching for lignin was obviously stronger than that of conventional bleaching, but it had a similar removal ability for hemicellulose. Furthermore, when the whiteness and yellowness values were similar, the amount of H 2 O 2 , bleaching temperature, and time of TAED-activated H 2 O 2 bleaching were obviously less than those of H 2 O 2 bleaching.
研究领域:
材料科学
·
纺织工程
✓ 已验证
产品关联
DOI
高影响因子
Biomass Conversion and Biorefinery
·
2023
·
IF 4
Zhao Shiqiang,Gui Gang,Zhang Weihong,Chen Wei,Zhao Sibo,Xu Guizhuan,Chang Chun
Levulinic acid (LA) is an important biobased platform chemical, which can be produced from carbohydrates via acid hydrolysis. However, the LA concentaration is usually low via the batch process, which is not conducive to its subsequent separation and purification. In this study, we improved the LA production by using novel fed-batch hydrolysis. Compared with the batch process, the LA yield of the one-time feeding process and two-time feeding process increased to 38.66% and 40.60% from 27.80%, the LA concentration increased to 49.83 g/L and 52.33 g/L from 35.83 g/L, respectively. The feasibility of using the waste solid residue generated during the LA production as filler was further investigated. The polyurethane foam was prepared with the incorporation of solid residue, and the compressive strength of the biobased polyurethane foam composites increased by 32.08% with the addition of 5% solid residue. The characterization of the biobased polyurethane foam indicated the solid residue can be used for polyurethane foam enhancement. This study provided a novel method for the efficient and clean production of LA and high-value utilization of the waste produced in the process.
研究领域:
生物化学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
CARBOHYDRATE POLYMERS
·
2017
·
IF 4.811
Xueqian Wang,Mengliu Zhang,Dawei Zhang,Shumei Wang,Chunyan Yan
Osteoporosis is characterized by a reduction in bone mass and bone mineral density, which weakens the bone. Due to the side effects associated with drugs that are currently used to treat this disease, an increasing number of studies have focused on the research of effective ingredients derived from natural products. In particular, polysaccharides extracted from Chinese herbal medicines have received increasing attention. In this study, we isolated a homogeneous polysaccharide (COP90-1) from the dried rhizomes of Curculigo orchioides , a famous traditional Chinese medicine that is widely used in China, and determined its structure using the combined methods of chemical and spectral analyses. In addition, its effects on the proliferation and differentiation of primary mouse osteoblasts were assessed. The results showed that COP90-1 can effectively promote the proliferation and differentiation of primary osteoblasts in vitro . Additional studies are warranted to study the effects of this compound in vivo .
研究领域:
药理学
·
天然产物化学
·
骨骼生物学
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产品关联
DOI
PubMed
高影响因子
TRANSITION METAL CHEMISTRY
·
2013
·Vol. 38
·期 4
·463-471
·
IF 1.184
Zhang Nan,Fan Yu-Hua,Bi Cai-Feng,Zhao Yu,Zhang Xia,Zhang Dong-Mei,Huang Gui-Mei
A pair of stereoisomers of nickel Schiff base complexes, namely [Ni(C 17 H 15 N 4 O 2 ) 2 ·2CH 3 OH] n ( 1 ) (C 17 H 15 N 4 O 2 = 2-acetylpyrazine- l -tryptophan) and [Ni(C 17 H 15 N 4 O 2 ) 2 ·2CH 3 OH] n ( 2 ) (C 17 H 15 N 4 O 2 = 2-acetylpyrazine- d -tryptophan), were synthesized and characterized by physico-chemical and spectroscopic methods. The X-ray diffraction single-crystal analyses indicate that the structure of 2 is essentially 0D monomeric, while a 2D layer structure is formed through N–H…O intermolecular hydrogen bonds for 1 . The interactions between complex 1 and calf thymus DNA were investigated by spectroscopic and viscometric methods. The results indicate that complex 1 interacts with DNA very strongly ( K
b = 1.01 × 10 7 mol −1 L and K
sq = 1.11). The nature of the binding seems to be mainly an electrostatic interaction between DNA and the complex. However, other binding modes, such as hydrogen bonding, may also be present in this system.
研究领域:
无机化学
·
配位化学
·
生物无机化学
·
分子药理学
·
核酸化学
✓ 已验证
DOI
高影响因子
Food Analytical Methods
·
2017
·Vol. 10
·期 12
·3847-3855
·
IF 2.038
Sun Bin,Wang Chunpeng,Wang Qi,Chen Ling,Dang Xueping,Huang Jianlin,Chen Huaixia
An acryloyl β -cyclodextrin (A- β -CD) monolithic column for solid-phase microextraction (SPME) and determination of carbofuran and carbaryl by high-performance liquid chromatography (HPLC) have been prepared through a “one-step” polymerization method. The synthesis conditions, including the volume of cross-linker, the ratio and volume of mixed porogenic solvent consisted of methanol and N,N -dimethylformamide were optimized. The prepared monolithic column was characterized by thermogravimeteric analysis (TGA), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), and Brunner-Emmet-Teller (BET) measurement. The eluent type, volume and flow rate, sample volume, flow rate, acidity, and ionic strength were optimized in detail. Under the optimized conditions, a simple, rapid, and sensitive SPME-HPLC method was developed for determination of carbofuran and carbaryl in rice samples. The method yielded a linear calibration curve in the concentration ranges of 1.5–200 μg/kg for carbofuran and 0.3–200 μg/kg for carbaryl with correlation coefficients ( R
2 ) of above 0.9955. Limits of detection ( S / N = 3) were 0.5 μg/kg for carbofuran and 0.1 μg/kg for carbaryl, respectively. The recoveries of this method ranged from 88.1 to 105.8%. The relative standard deviations were less than 8.1%.
研究领域:
分析化学
·
食品科学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）