FUEL
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2019
·
IF 5.128
Balaji Panchal,Tao Chang,Shenjun Qin,Yuzhuang Sun,Jinxi Wang,Kai Bian
The objective of this study was to use n -hexane containing an ionic liquid for the extraction of oil and transesterification for the production of methyl esters from Jatropha curcas oil. A solid acidic ionic liquid polymer was synthesized using vinyl imidazole, 1,3-propane sultone, N , N -dimethylhexadecyl amine, allyl bromide, toluene, and the product was characterized by NMR and used for the transesterification. The optimum reaction conditions that resulted in the highest methyl ester yield of 94% were a J. curcas oil-to-dimethyl carbonate molar ratio of 1:5, a solid acidic ionic liquid polymer catalyst loading of 260 wt%, for 6 h with 500 rpm at 80 °C. Methyl esters were purified using celite powder and then analyzed by GC–MS. The activation energy and reaction rate constant were calculated from 4.862 to15.382 kJ/mol, and 0.389 to 4.602, respectively. The methyl esters met the quality standards defined under ASTM D6751-02.
研究领域:
化学工程
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可再生能源
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL THERMODYNAMICS
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2018
·
IF 2.631
Jing Fan,Qi Liu,Fenhong Song,Xiaopo Wang,Lihui Zhang
The utilization of biodiesel is a promising way to replace fossil fuels, and thermal conductivity of biodiesel is a very important thermophysical property for its applications. In this work, the transient hot-wire instrument with one bare platinum wire was used to measure the thermal conductivity of five pure components of biodiesel in liquid phase at atmospheric pressure. The measured substances include methyl butyrate, methyl pentanoate, methyl caproate, methyl caprylate, and methyl pelargonate, and the temperature range was from (283 to 358) K, (285 to 362) K, (263 to 368) K, (273 to 393) K, (278 to 383) K, respectively. The total standard uncertainty of the experimental results was estimated to be less than 2% and the repeatability was better than ±0.5%. The thermal conductivity data of each substance were fitted as a function of temperature. The average absolute relative deviation and maximum absolute relative deviation between the experimental data and calculated results were 0.17% and 0.44% for methyl butyrate, 0.25% and 0.58% for methyl pentanoate, 0.16% and 0.44% for methyl caproate, 0.15% and 0.47% for methyl caprylate, 0.15% and 0.33% for methyl pelargonate, respectively.
研究领域:
能源科学
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热物理学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL THERMODYNAMICS
·
2021
·
IF 3.178
Xiong Zheng,Yanqiong Bao,Dan Qu,Yu Liu,Guangzhao Qin
Fatty acid methyl esters (FAMEs) are the main component of biodiesels. Before the industrial application of FAMEs, it is essential to investigate the thermophysical properties of FAMEs. Thermal conductivity of fuels is used in various processes, such as the design of the heat transfer system and the determination of the temperature distribution of engines. Thus, it is of great significance to acquire accurate experimental data and develop reliable models for obtaining accurate thermal conductivity data of FAMEs. In this work, thermal conductivities of two short-chain FAMEs, methyl butyrate (MeC4:0) and methyl caproate (MeC6:0) were studied experimentally and theoretically. The thermal conductivities of these two FAMEs were measured by the transient hot-wire method at T = 303 to 523 K and p = 0.1 MPa to 15 MPa, the data were correlated as a polynomial function of temperature and pressure, the AADs are 0.38% for MeC4:0 and 0.42% for MeC6:0, respectively. Moreover, the experimental thermal conductivities agree well with the available data from literature. In addition, three classical models (Latini model, Sastri model, Liu model) were used to represent the present experimental data and the results show that Liu model with re-fitted parameters performs better in the prediction of the thermal conductivity of FAMEs, with regard to accuracy.
研究领域:
能源科学
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物理化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF PLANT PHYSIOLOGY
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2022
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IF 3.686
Shuangxi Zhang,Huachun Sheng,Yue Ma,Yanping Wei,Dan Liu,Yanhua Dou,Huiying Cui,Boyou Liang,Johannes Liesche,Jisheng Li,Shaolin Chen
Cell wall biogenesis is required for the production of seeds of higher plants. However, little is known about regulatory mechanisms underlying cell wall biogenesis during seed formation. Here we show a role for the phosphorylation of Arabidopsis cellulose synthase 1 (AtCESA1) in modulating pectin synthesis and methylesterification in seed coat mucilage. A phosphor-null mutant of AtCESA1 on T166 ( AtCESA1 T166A ) was constructed and introduced into a null mutant of AtCESA1 ( Atcesa1-1 ). The resulting transgenic lines showed a slight but significant decrease in cellulose contents in mature seeds. Defects in cellulosic ray architecture along with reduced levels of non-adherent and adherent mucilage were observed on the seeds of the AtCESA1 T166A mutant. Reduced mucilage pectin synthesis was also reflected by a decrease in the level of uronic acid. Meanwhile, an increase in the degree of pectin methylesterification was also observed in the seed coat mucilage of AtCESA1 T166A mutant. Change in seed development was further reflected by a delayed germination and about 50% increase in the accumulation of proanthocyanidins, which is known to bind pectin and inhibit seed germination as revealed by previous studies. Taken together, the results suggest a role of AtCESA1 phosphorylation on T166 in modulating mucilage pectin synthesis and methylesterification as well as cellulose synthesis with a role in seed development.
研究领域:
植物生物学
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分子遗传学
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细胞壁生物合成
✓ 已验证
DOI
PubMed
高影响因子
PHARMACEUTICAL CHEMISTRY JOURNAL
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2024
·Vol. 57
·期 8
·1174-1178
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IF 0.8
Zheng Qing-Xuan,Wang Rui,Li Hui-Jing,Dehaen Wim,Huai Qi-Yong
Oleanolic acid (OA) is a natural product with certain antitumor activity. In order to enhance its cytotoxicity, a total of five derivatives of OA were designed and synthesized. Their cytotoxicity against MDA-MB-231cells (human breast cancer cells), A549 cells (human nonsmall cell lung cancer cells) and BEAS-2B cells (human cervical cancer cells) were evaluated by the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) method. The results indicated that these target compounds have a wide molar activity range and some of them showed better activity than the commercial drug, doxorubicin. Compound 2a induces apoptosis of 14, 27, and 56% of MDA-MB-231 cells at 2, 4, and 8 mM respectively, and shows a linear correlation of concentration.
研究领域:
肿瘤学
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药物化学
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分子药理学
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天然产物化学
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转化医学
✓ 已验证
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2025
·
IF 3.9
Xi Liu,Delong Hou,Demeng Liu,Siyu Pan,Jun Yan,Qi Zeng,Yi Chen
The α-methyl esterification of natural fatty acid methyl esters (FAMEs) is an essential approach for preparing high-value chemicals such as migration-resistant bioplasticizers, polyester precursors, and anionic surfactants. However, previous strategies are primarily based on time-consuming Claisen condensation, which utilizes petroleum-derived dimethyl carbonate (DMC) as a building block for α-methyl esterification, as well as a NaH/DMF deprotonation system with a highly explosive risk. Here, we present an efficient approach that harnesses carbon dioxide as a green C1 building block to facilitate rapid, nonexplosive α-methyl esterification of FAMEs, producing fatty acid dimethyl esters with high yield (>85%) at ambient temperature within 3 h. Various natural FAMEs, even those derived from waste cooking oil, are amenable to this approach. Our findings establish a robust strategy for α-methyl esterification of FAMEs, bringing the production of high-value chemicals from FAMEs one step closer to sustainability.
研究领域:
绿色化学
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有机合成
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可持续化学
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二氧化碳利用
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生物炼制
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
FOOD HYDROCOLLOIDS
·
2023
·
IF 10.7
Yuxin Wang,Jiaxin Liu,Li chen,Shuang Jin,Can An,Long Chen,Bao Yang,Henk A. Schols,Paul de Vos,Weibin Bai,Lingmin Tian
Pomelo peel, a by-product of fruit processing, is an excellent source of pectin. We aimed to study the effects of thermal treatments on the extraction and in vitro fermentation patterns of pectins from pomelo peel. We used subcritical water extraction and hot water extraction, with or without chelator (citric acid or EDTA-2Na) assistance to obtain the pectins. The pectin fractions were characterized by their constituent monosaccharide composition and molecular weight (Mw) distribution. The degree of methyl esterification of pomelo pectins was determined using FT-IR spectroscopy. We also compared the fermentation patterns of the pectin using an in vitro simulated human gut fermentation model, monitored Mw changes during fermentation by high performance size exclusion chromatography (HPSEC), and analyzed short-chain fatty acid (SCFA) using gas chromatograph. Our results showed that both chelator assistance and subcritical water treatment increased the pectin yield. Chelator-assisted extraction increased the pectin Mw and decreased the degree of methyl esterification (DM) whereas, subcritical water treatment had the opposite effect. Pectin with low rhamnogalacturonan-I (RG-I) and high homogalacturonan (HG) domain can be obtained from the used pomelo peels by citric acid-assisted extraction. Although gut microbiota intensively utilized uronic acid (UA) of pomelo during early fermentation stages, constituent neutral monosaccharides were consumed even faster than UA. Pomelo pectins enhanced the relative abundance of Bacteroides and Prevotella 9 , and stimulated the production of SCFA, particularly acetic acid. Generally, pomelo pectin could be considered a new source for modulating gut microbiota towards a healthy pattern in functional foods.
研究领域:
食品科学
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营养学
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微生物学
·
生物技术
✓ 已验证
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2012
·
IF 2.237
Liangyan Wang,Xiabin Jing,Haibo Cheng,Xiuli Hu,Lixin Yang,Yubin Huang
The long-chain branched polylactides (LCB-PLAs) prepared by coupling the hydroxyl-terminated two-arm (linear) and triarm PLA prepolymers of identical arm length with hexamethylenediacianate (HDI) were used to improve the melt rheological and crystallization properties of linear polylactide resin, PLA 4032D from NatureWorks. The blends containing LCB-PLA displayed higher zero shear viscosities, more significant shear shinning, more melt elasticity, and much longer relaxation times together with significant strain hardening in elongational deformation. Tg, Tm and crystallinity (Xc) of linear PLA remained virtually unaffected, but the crystallization rate increased obviously, since the branch points of LCB-PLAs could play a role of nucleating agent. High melt strength, fast crystallization, and favorable miscibility improved the foaming ability of the linear/LCB-PLA blends, substantially.
研究领域:
高分子科学
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材料科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2024
·
IF 7.7
Tong Zhao,Sining Liu,Yutong Shuai,Xinyi Zhang,Min Chen,Sijie Pei,Yuxi Duan,Shukai Wang,Yu Lu,Zhongfu Wang,Guiping Gong,Linjuan Huang
Pectin is a structurally complex heteropolysaccharide that affects intestinal microorganisms and mucin O -glycans. The present study employed an in vitro model to investigate dynamic changes in microbiota during pectin fermentation. Residual pectin fragments arising from its fermentation were applied to HT29-MTX cells to study the effect of pectin structure on mucin O -glycosylation. Prevotella , Bacteroides , and Parabacteroides were found to preferentially degrade galactose, arabinose, and on the rhamnogalacturonan RG-I side chain region and methyl esterification groups of pectin. Bifidobacterium , Enterococcus , Megamonas , and Dorea metabolized the galacturonic HG region on pectin to produce butyrate. All pectin fragments were found to up-regulate total O -glycans (1.55–2.73 fold) and neutral O -glycans (1.11–1.49 fold) on HT29-MTX mucins. The large HG fragment (81.04 kDa) increased significantly the amount of non-fucosylated glycans (by 2.46-fold); whereas the small HG fragment (16.02 kDa) promoted fucosylated (by 9.25 fold), and especially di-fucosylated O -glycans. Collectively, these results demonstrate that gut microorganisms degrade pectin fragments in the following order of utilization: RG-I, RG-II, and HG. The small fragment of HG improves the expression of fucosylated O -glycans in HT29-MTX cells, mainly owing to an increase in di-fucosylated O -glycans.
研究领域:
微生物学
·
胃肠病学
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细胞生物学
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营养科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）