FOOD CHEMISTRY
·
2018
·
IF 4.946
Xiao-dan Shi,Ou-ye Li,Jun-yi Yin,Shao-ping Nie
Dictyophora echinovolvata is a kind of edible mushroom in the Dictyophora genus, of which polysaccharide is an important chemical substance. Herein, three polysaccharide fractions (DEP-4P, DEP-6P and DEP-8P) were prepared from water extract of D. echinovolvata using gradient ethanol precipitation method. Their chemical structures were analyzed by methylation analysis and 1D/2D NMR spectroscopy. Molecular weights were determined by multi-angle laser light scattering combined with size-exclusion chromatography (HPSEC-MALLS). HPSEC data showed that DEP-4P had the highest values of molecular weight, intrinsic viscosity and hydrodynamic radius. DEP-6P and DEP-8P had lower molecular weights, which contributed to their easily distinguished 1D and 2D NMR spectra. Methylation and NMR analysis suggested that the three fractions were linear α-(1 → 4)-glucans with α-Glc p residues linked to the backbone at C -6. Differences among the three fractions were the molar ratios of the identified glycosidic bonds. Repeating units of polysaccharides from D. echinovolvata were proposed as follows: Download : Download high-res image (60KB) Download : Download full-size image
研究领域:
生物化学
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食品科学
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DOI
PubMed
高影响因子
Gas Science and Engineering
·
2023
·
IF 0
Rui Zhang,Haonan Liu,Ruixi Liu,Yingjie Niu,Luning Yang,Francesco Barzagli,Chao'en Li,Min Xiao
The blending of primary amines, with fast reaction kinetic, together with tertiary amines, with a large loading capacity, is an increasingly popular approach to develop high-performance CO 2 capture sorbents with low energy requirements for regeneration. In this study, we investigated the CO 2 absorption performance of several aqueous solutions obtained by mixing ethanolamine (MEA) and diethylethanolamine (DEEA) and compared them with that of individual MEA and DEEA. CO 2 loadings at equilibrium were measured experimentally under a wide range of operating conditions, at temperatures between 298 and 323 K, CO 2 partial pressures in the range 5–60 kPa, and different amine mixing ratios. In addition, 13 C NMR spectroscopy was employed to elucidate the reaction mechanisms and identify the species formed during CO 2 capture. The results of the study reveal the intricate interplay of MEA and DEEA in CO 2 capture, where MEA carbamate formation predominates in the early stages, gradually shifting to bicarbonate formation as the amine concentration decreases. Moreover, excess properties, which reflect non-ideal behaviors in amine blends, were introduced as a key parameter in the study. An excess property model, based on excess CO 2 loading, was developed to accurately predict the CO 2 equilibrium solubility without constant experimental measurement. As a result, good agreement was found between the experimental data and those calculated with the model (excess CO 2 loading) under the same operating conditions, with a average relative deviation of 1.1%.
研究领域:
化学工程
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环境科学
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DOI
SEPARATION AND PURIFICATION TECHNOLOGY
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2024
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IF 8.1
Haonan Liu,Francesco Barzagli,Li Luo,Xin Zhou,Jiaofei Geng,Chao’en Li,Min Xiao,Rui Zhang
The combination of primary and tertiary amines represents a promising approach to improve sorbent performance in CO 2 capture by enhancing absorption efficiency and reducing regeneration energy. This study focuses on investigating the absorption performance of binary mixtures of ethanolamine (MEA) and N,N-dimethylethanolamine (DMEA) at temperatures between 298–323 K and CO 2 partial pressures between 5–60 kPa. The species generated during the absorption were analyzed using 13 C NMR spectroscopy, to clarify the intricate role of MEA and DMEA in the capture process. A developed excess property model for MEA-DMEA, based on excess CO 2 loading, predicted equilibrium CO 2 solubility data with an average absolute relative deviation (AARD) of 1.6 %. Additionally, the machine learning models XGBoost, RBFNN, and SVR were applied, providing AARD values between 0.86 % and 1.28 %, demonstrating strong agreement between experimental and predicted outcomes. These comprehensive findings enhance our understanding of mixed amines’ mechanisms and practical applications, contributing to ongoing research development.
研究领域:
化学工程
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环境科学
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机器学习
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DOI
高影响因子
JOURNAL OF SOLUTION CHEMISTRY
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2018
·Vol. 47
·期 4
·705-714
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IF 1.401
Li Qiang,Liu Bijun,Mu Wanjun,Yu Qianhong,Tian Yin,Liu Guoping,Yang Yuchuan,Li Xingliang,Luo Shunzhong
Glufosinate, an analogue of glutamic acid (also known as phosphinothricin), is an important herbicide. The protonation constants of glufosinate were determined by means of potentiometric titrations at variable temperatures with ionic strength 0.5 mol·L −1 (NaCl solution). The heat effects of the protonation reactions of glufosinate were measured by direct calorimetry. NMR spectroscopies have demonstrated that the first protonation site occurs on the nitrogen atom in the amino group, followed by one of the oxygen atoms in the phosphono group, and finally the carboxyl oxygen atom. This trend is in good agreement with the enthalpy of protonation and crystal structure results. These data will help to predict the speciation of glufosinate in physiological systems.
研究领域:
植物学
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化学
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环境科学
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DOI
高影响因子
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
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2011
·Vol. 13
·期 32
·14542-14549
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IF 3.454
Kelei Zhuo,Yujuan Chen,Jing Chen,Guangyue Bai,Jianji Wang
Extensive applications of ionic liquids (ILs) may result in their accumulation in the ecological environment and organisms. Although ILs are popularly called “green solvents”, their toxicity, in fact, has been exhibited. Therefore the interaction of ILs with biomolecules is a cutting-edge research subject. Herein, the interactions of 1-butyl-3-methylimidazolium carboxylate ionic liquids ([C4mim][HCOO], [C4mim][CH3COO] and [C4mim][CH3CH2COO]) with glucose in water were studied for their volumetric properties, viscosity, conductivity and NMR spectra. Limiting apparent molar volumes (V0Φ,IL), viscosity B-coefficients, limiting molar conductivities (Λ0) and Walden products (Λ0η0) were evaluated for the ILs in glucose + water solutions. Volumetric interaction parameters were also obtained from the transfer volumes of the ionic liquids. The contributions of the solvent properties (B1) and the ionic liquid–solvent interactions (B2) to the B-coefficient were extracted, together with molar activation energies (Δμ0≠IL) of the ionic liquids for viscous flow of the aqueous glucose + IL solution. In addition, the 13C and 1H NMR spectra of methyl β-D-glucopyranoside and ILs in β-D-glucopyranoside + IL + D2O were studied. The NMR results show that no special and strong interactions were observed between glucopyranoside and the ILs. However, it was confirmed that the H2 on the imidazolium ring has more activity (acidity) than atoms H4 and H5. The macro-properties and their changes were also discussed in terms of the size, structure and solvation of the ILs and glucose.
研究领域:
生物化学
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环境科学
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分析化学
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产品关联
DOI
PubMed
高影响因子
FOOD HYDROCOLLOIDS
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2021
·
IF 9.147
Wei Tang,Dan Liu,Yu Li,Ming-Yue Zou,Yu-Chen Shao,Jun-Yi Yin,Shao-Ping Nie
The water-extracted polysaccharide from Portulaca oleracea L. mainly consisted of two pectic polysaccharides designated as POWP-H and POWP-L. The POWP-L was rich in linear homogalacturonan with GalA content of 77.6%, while POWP-H might be a rhamnogalacturonan I (RG-I) pectin composed of Rha (15.7%), Ara (31.7%), Gal (42.5%) and GalA (10.1%). The structure of POWP-H was elucidated by partial degradation, methylation analysis combined with GC-MS method and NMR spectroscopy. It had a weight-average molecular weight of 1.2 × 10 6 g/mol and high degree of branch of 0.57. The presence of abundant arabinogalactan-II and certain galactan side chains in POWP-H was verified by the T-Ara f (17.4%), 1,3,6-Gal p (11.8%), 1,3-Gal p (8.1%), T-Gal p (13.4%) and 1,4-Gal p (14.3%). The evidence for the RG-I backbone of POWP-H was demonstrated by the structure analysis of its degraded product POWP-H-H, which had the backbone of →4)-α-Gal p A-(1 → 2)-α-Rha p -(1 → 4)-α-Gal p A-(1 → 2,4)-α-Rha p -(1→ substituted by short side chain of β-Gal p -(1 → 4)-β-Gal p -(1→ at O -4 position of →2,4)-α-Rha p -(1 → . Moreover, the POWP-H-H was mainly O -acetylated at O -3 position of α-Rha p with 24.8% acetylation degree. In conclusion, POWP-H was mainly the highly branched and acetylated RG-I pectin with relative short RG-I backbone and abundant arabinogalactan II and certain galactan side chains. Besides, it adopted a flexible chain conformation in 0.1 M NaNO 3 solution.
研究领域:
植物化学
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食品科学
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分子生物学
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DOI
高影响因子
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
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2021
·
IF 5.279
Pengfei Liu,Jiaojiao Zhang,Yan Qiao,Xianglin Hou,Yu Liu,Yingxiong Wang
Using environment-friendly catalysts to convert biomass into compounds with high values is one of the central topics of green chemistry. In this work, [Ch][Pro] (cholinium as the cation and l-proline as the anion) ionic liquid was synthesized and applied as a model catalyst in the production of deoxyfructosazine (DOF) and fructosazine (FZ) from d-glucosamine (GlcNH2). The 13C NMR chemical shift titration experiments and the diffusion-ordered NMR spectroscopy (DOSY) measurements showed that, when the [Ch][Pro] interacted with GlcNH2, the l-proline anion ([Pro]−) played a major catalytic role instead of cholinium cation ([Ch]+). The effects of the reaction temperature and the amount of [Ch][Pro] on the product yields were surveyed. The experimental results showed that the highest DOF yield (33.78%) was obtained after 30 min at 100 °C when the molar ratio of [Ch][Pro]/GlcNH2 was 1. Moreover, in situ1H NMR and in situ13C NMR experiments were applied to monitor the reaction process with [Ch][Pro] as the catalyst. The reactive intermediate, dihydrofructosazine, was clearly detected by these in situ techniques. Accordingly, a possible reaction pathway was proposed. By applying other amino acids as the anions, we also prepared five other [Ch][AA] ionic liquids, and they showed different catalytic activities and selectivity in the GlcNH2 self-condensation reaction.
研究领域:
绿色化学
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催化化学
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生物质转化
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DOI
PubMed
高影响因子
CARBOHYDRATE POLYMERS
·
2025
·
IF 12.5
Shasha Tian,Zian Mao,Yuexia Wang,Kewei Li,Yafei Li,Bingqi Zhu,Fangmei Zhou,Jingchao Li,Yingzhi Shen,Zhishan Ding
Tetrastigma hemsleyanum Diels et Gilg ( T. hemsleyanum ) is a rare traditional Chinese medicine with high medicinal value and T. hemsleyanum polysaccharides (THPs) have attracted increasing attention in recent years. However, detailed structural and functional insights into THPs remain limited. Here, a novel pectic polysaccharide (STHP4) with an average molecular weight (Mw) of 119 kDa was extracted and purified from the aboveground part of T. hemsleyanum . Structurally, STHP4 was mainly composed of galacturonic acid, glucuronic acid, and galactose, with minor glucose, rhamnose, arabinose, and mannose, and its primary backbone was 1,4-GalA. Pectinase treatment of STHP4 yields two distinct fractions: STHP4-1 and STHP4-2. STHP4-1 shared the same types of monosaccharides with STHP4, except for the absence of glucose, but had a broad Mw distribution (9.9 to 251 kDa). Another product, STHP4-2, a mixture of oligosaccharides and free monosaccharides, has a Mw of 1.387 kDa. Their structures were further elucidated via methylation analysis and NMR spectra. Furthermore, STHP4-1 exhibited superior immune regulatory effects on macrophages, including increased nitric oxide release and elevated interleukin-6, interleukin-1β, and tumor necrosis factor α expression. These findings suggest that STHP4-1 might be the core active domain of STHP4, and both STHP4 and STHP4-1 are potential immune enhancers.
研究领域:
植物化学
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免疫学
·
药理学
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DOI
PubMed
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2019
·Vol. 43
·期 18
·7028-7034
·
IF 3.069
Weitao Xu,Ming Liu,Mary Clare Escaño,Carl Redshaw,Bing Bian,Ying Fan,Zhu Tao,Xin Xiao
The interaction between cucuribit[10]uril (Q[10]) and a series of 4-pyrrolidinopyridinium salts bearing aliphatic substituents at the pyridinium nitrogen, namely 4-(C4H8N)C5H5NRBr, where R = Et (g1), n-butyl (g2), n-pentyl (g3), n-hexyl (g4), n-octyl (g5), n-dodecyl (g6), has been studied in aqueous solution by 1H NMR spectroscopy, electronic absorption spectroscopy and mass spectrometry. The results revealed that the guests g1–g5 are located completely inside the cavity differing only in the orientation of g1, g4 and g5 which are aligned with the portal, whilst g2 and g3 are perpendicular to it. For g6, the tetrahydropyrrole moiety remains outside of the portal. DFT calculations confirm the stability of the guests in the Q[10] and the possibility of their curved structure inside the Q[10].
研究领域:
化学
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分子生物学
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DOI
高影响因子
JOURNAL OF PHYSICAL CHEMISTRY B
·
2016
·
IF 3.187
Bijun Liu,Lan Dong,Qianhong Yu,Xingliang Li,Fengchang Wu,Zhaoyi Tan,Shunzhong Luo
Glyphosate [N-(phosphonomethyl)glycine] has been described as the ideal herbicide because of its unique properties. There is some conflicting information concerning the structures and conformations involved in the protonation process of glyphosate. Protonation may influence the chemical and physical properties of glyphosate, modifying its structure and the chemical processes in which it is involved. To better understand the species in solution associated with changes in pH, thermodynamic study (potentiometry, calorimetry and NMR spectroscopy) about the protonation pathway of glyphosate is performed. Experimental results confirmed that the order of successive protonation sites of totally deprotonated glyphosate is phosphonate oxygen, amino nitrogen, and finally carboxylate oxygen. This trend is in agreement with the most recent theoretical work in the literature on the subject ( J. Phys. Chem. A 2015,, 119, 5241−5249). The result is important because it confirms that the protonated site of glyphosate in pH range 7–8, is not on the amino but on the phosphonate group instead. This corrected information can improve the understanding of the glyphosate chemical and biochemical action.
研究领域:
化学
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环境科学
·
生物学
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DOI
PubMed
高影响因子
Journal of Magnetic Resonance Open
·
2025
·
IF 2
Bowen Han,Jing He,Shaohua Huang
Chiral amino acids play an indispensable role in living organisms. Diffusion-ordered NMR spectroscopy is an effective NMR tool and a noninvasive analytical method for the analyses of mixture without the need for physical separation of the analytes. However, conventional diffusion-ordered NMR spectroscopy method usually fails to resolve the mixtures of chiral amino acids because of their same molecular masses, sizes, and shapes. Microcrystalline cellulose has been gradually gained more and more interest owing to its wide compatibility, surface area, excellent separation efficiency, non-toxicity, cost-effective, and mechanical stability in many fields. Herein we provide a fast, simple, specific and sensitive method to resolve some D and L-amino acids mixtures by using microcrystalline cellulose as a matrix. This work recognized some D and L- proteinogenic amino acid enantiomers with diffusion-ordered NMR for the first time.
研究领域:
分析化学
·
生物化学
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DOI
高影响因子
RSC Advances
·
2015
·Vol. 5
·期 16
·12007-12014
·
IF 3.84
Lingxing Zhang,Huan Zhang,Fei Gao,Huiying Peng,Yonghong Ruan,Yuanze Xu,Wengui Weng
An azobenzene derivative (F-azo-COOH) was synthesized and could be E/Z isomerized by visible light. The host–guest interaction between F-azo-COOH and cyclodextrins (CDs) in alkaline aqueous solution was studied by NMR spectroscopy for the first time. The results revealed that F-azo-COOH did not form a stable host–guest complex with α-CD. However, both trans- and cis-F-azo-COOH could form stable 1 : 1 complexes with β-CD. Most interestingly, cis-F-azo-COOH could fit the cavity of β-CD more tightly (3.0 ± 0.3 × 103 M−1) than its trans form (2.1 ± 0.2 × 103 M−1), which was completely opposite to the conventional azobenzene/β-CD system.
研究领域:
化学
·
材料科学
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）