FOOD CHEMISTRY
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2024
·
IF 8.5
Yejun Zhang,Yongzhen Wang,Hao Dong,Jiao Li,Jianan Sun,Xiangzhao Mao
Temperature fluctuations can negatively affect the quality of frozen shrimp. Research on novel cryoprotectants to replace traditional agents (phosphate, etc.) has become a hotspot. Our results indicated that L-Proline could reduce thawing losses, delay texture deterioration and improve the functional properties of myofibrillar proteins of shrimp. Thawing loss in the proline group (3.2 %) was significantly lower than that in the control (5.4 %) after 3 freeze-thaw cycles ( p < 0.05). Compared to Na 4 P 2 O 7 , proline had better permeability and greater ability to inhibit ice crystal growth and volume expansion. Through molecular simulations, we found that proline might inhibit ice crystal formation by forming glassy states with water. Hydrogen bonding between proline and water/ice played a major role, and only a small amount of proline was required to significantly reduce the ice crystal growth rate from 0.16 m/s to 0.06 m/s. Briefly, proline exhibited potential as a cryoprotectant for shrimp in temperature fluctuations.
研究领域:
食品科学
·
分子生物学
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产品关联
DOI
PubMed
高影响因子
GREEN CHEMISTRY
·
2020
·Vol. 22
·期 13
·4222-4230
·
IF 9.48
Jiayuan Yu,Anker Degn Jensen,Lei Wang,Chunshan Li,Suojiang Zhang
Methacrolein (MAL) is an important chemical for the manufacture of methyl methacrylate and a key monomer in many polymerization reactions. In this study, L-proline was investigated as the catalyst for the aldol condensation of formaldehyde and propionaldehyde to produce MAL. The catalytic activity of the reaction system was closely related to the competition between the main reaction synthesizing MAL and the side reaction producing 2-methyl-2-pentenal, which could be modified by adjusting the operating parameters. The influences of several operating conditions, including temperature, reaction time and water content, on the catalytic performance of the system were systematically studied via a series of single-factor experiments, and the optimized reaction conditions were obtained. The mechanistic investigation via ESI-MS indicated that the reaction pathway followed the Mannich route. Experimental and theoretical kinetic analyses of the L-proline-catalyzed aldol condensation reaction were performed, and the reaction orders of the reactants were obtained by regression. The results showed that L-proline was an efficient catalyst for the production of MAL via aldol condensation under mild conditions.
研究领域:
化学工程
·
有机化学
✓ 已验证
产品关联
DOI
高影响因子
Catalysts
·
2021
·Vol. 12
·期 1
·42
·
IF 4.146
Longxin Ju,Gang Li,Hongxian Luo
Aldol condensation reactions are very important C–C coupling reactions in organic chemistry. In this study, the catalytic performance of layered double hydroxides (LDHs) in the aldol condensation reaction of formaldehyde (FA) and propionaldehyde (PA) was investigated. The MxAl-LDHs (denoted as re-MxAl–LDHs; M = Ca and Mg; X = 2–4), as heterogeneous basic catalysts toward the aldol condensation reaction, were prepared via a two-step procedure. The catalyst exhibited a high PA conversion (82.59%), but the methacrolein (MAL) selectivity was only 36.01% due to the limitation of the alkali-catalyzed mechanism. On this basis, the direct intercalation of L-proline into LDHs also has been investigated. The influences of several operating conditions, including the temperature, reaction time, and substrate content, on the reaction results were systematically studied, and the optimized reaction conditions were obtained. The optimized Mg3Al–Pro-LDHs catalyst exhibited a much higher MAL selectivity than those of re-MgxAl–LDHs.Keywords:layered double hydroxides;L-proline;aldol condensation reaction
研究领域:
有机化学
·
催化材料科学
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产品关联
DOI
高影响因子
International Journal of Chemical Engineering
·
2014
·
IF 0
Hu Li,Song Yang
L-Proline derived ionic liquids (ILs) used as both solvent and catalyst were efficient for transformation of fructose and sucrose to 5-hydroxymethylfurfural (HMF) in the presence of water. Response surface methodology (RSM) was employed to optimize fructose dehydration process, and a maximum HMF yield of 73.6% could be obtained at 90°C after 50 min. The recycling of the IL exhibited an almost constant activity during five successive trials, and a possible reaction mechanism for the dehydration of fructose to HMF was proposed.
研究领域:
化学工程
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催化反应
✓ 已验证
产品关联
DOI
Biomass Conversion and Biorefinery
·
2021
·Vol. 12
·期 1
·87-93
·
IF 4.987
Wang Yun,Yao Qiao-Xia,He Jia-Rui,Liang Zhi-Hui,Li Xiang,Cheng Hong,Li Li-Ling
Knoevenagel condensation of acetylacetone and aromatic aldehyde catalyzed by L-proline in the choline chloride-based deep eutectic solvents was achieved. High yields are up to 96.6%. Mild reaction conditions, enhanced rates, improved yields, recyclability of deep eutectic solvents containing L-proline, and reagents’ reactivity which is different from that in standard organic solvents are the remarkable features observed in deep eutectic solvents. The deep eutectic solvents containing catalyst was recycled in four subsequent runs with no decrease in activity.
研究领域:
有机化学
·
绿色化学
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产品关联
DOI
高影响因子
CHEMICAL PAPERS
·
2020
·Vol. 74
·期 11
·3839-3846
·
IF 1.68
Cai Zhifeng,Zhu Ruitao,Zhang Caifeng,Hao Erxiao,Zhao Jie,Wu Tianqi
Herein, a simple, green and low-cost method was established to synthesize l -proline-stabilized copper nanoclusters ( l -Pro-Cu NCs) with good water solubility, excellent photostability and resistance to sodium chloride. A series of methods including fluorescence spectroscopy, UV–Vis absorption spectroscopy, Fourier transform infrared spectroscopy, transmission electron microscopy and X-ray photoelectron spectroscopy were used to characterize the structure and optical performance of the Cu NCs. The as-prepared Cu NCs showed green fluorescence with the excitation wavelength of 373 nm. Under the optimal detection conditions, an excellent linear relationship was observed between relative fluorescence intensity ( F 0 / F ) and the concentrations of quercetin ranging from 0.5 to 50 μM, and the detection limit (LOD) was 0.012 μM. Moreover, the proposed method provided an excellent platform for the detection of quercetin in the real samples.
研究领域:
分析化学
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纳米材料科学
·
生物医学
✓ 已验证
DOI
高影响因子
BIOSENSORS & BIOELECTRONICS
·
2013
·
IF 5.437
Xiaoyu Mu,Li Qi,Ping Dong,Juan Qiao,Jian Hou,Zongxiu Nie,Huimin Ma
Gold nanoclusters (Au NCs) possess outstanding physical and chemical attributes that make them excellent scaffolds for the construction of novel chemical and biological sensors. In this study, a simple one-pot synthesis method, employing l -proline as the stabilizer, was presented for preparation of fluorescent Au NCs. This strategy allowed the generation of water-soluble Au NCs within a short time of 15 min. The as-prepared Au NCs exhibited a bluish fluorescence emission at 440 nm and a quantum yield of 2.94%. Based on the aggregation-induced fluorescence quenching mechanism, the Au NCs provided favorable biocompatibility, high sensitivity and good selectivity for the measurement of ferric ion (Fe 3+ ). Furthermore, serum samples were analyzed for the serum iron contents by using this proposed biocompatible fluorescent sensor, indicating the potential value of this Au NCs-based fluorescent sensor for application in biological and clinical analysis.
研究领域:
分析化学
·
生物医学
✓ 已验证
DOI
高影响因子
ACS Sustainable Chemistry & Engineering
·
2020
·
IF 7.632
Ying Sun,Shuhang Ren,Yucui Hou,Kai Zhang,Qi Zhang,Weize Wu
A series of environmentally benign functional ionic liquids (ILs) based on l-proline as the anion to efficiently absorb low-concentration NO have been investigated in this work. The results indicate that the ILs with an l-proline anion have high absorption capacities for 0.16 vol % NO, reaching a maximum absorption capacity of 0.51 mol of NO per mol of IL at 30 °C and ambient pressure for l-proline choline IL ([Ch][l-Pro]). The absorbed NO could be recovered from [Ch][l-Pro], and the regenerated IL had no significant loss of NO absorption capacity for at least 7 recycles. We verified the mechanism through both experimental and theoretical methods. The results indicate that the absorption of NO in [Ch][l-Pro] mainly resulted from a chemical process—NO and the secondary amine group in the anion form a NONOate with a chemical formula [l-Pro]−–(NO)–NO. We believe that this efficient and reversible absorption of low-concentration NO by the ILs has potential as a new NO capture technique.
研究领域:
环境科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
Biomass Conversion and Biorefinery
·
2022
·
IF 4.05
Wang Yun,Dong Kai-hui,Zhen Miao-lan,He Jia-Rui,Yao Qiao-xia
The Knoevenagel condensation of aromatic aldehydes and ethyl acetoacetate catalyzed by L-proline in water, ionic liquid, and deep eutectic solvents (DESs), respectively, was studied. The mild reaction conditions, enhanced rates, improved yields, and reagents’ reactivity are observed in deep eutectic solvents. The highest yields are up to 94.4%. The Z/E selectivity of products is up to 3.21. In addition, the influencing factors of product configuration were studied by calculation and experiment.
研究领域:
有机化学
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催化化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL RESEARCH
·
2015
·
IF 0.633
Fang-Ming Wang,Dan Bao,Bing-Xiang Hu,Ze-Yu Zhou,Deng-Deng Huang,Li-Zhuang Chen,Yuan-Yuan Dan
A series of novel 10-substituted 3,6-diphenyl-9-aryl-3,4,6,7,9,10-hexahydroacridine-1,8(2H,5H)-dione derivatives synthesised by condensation of different amines with xanthenes, was prepared from 5-phenylcyclohexane-1,3-dione and aromatic aldehydes by a Knoevenagel and Michael reaction and cyclisation catalysed by a trace of l-proline at room temperature. In addition, the molecular structure of a xanthene was determined by single-crystal X-ray diffraction analysis.
研究领域:
有机化学
·
药物化学
✓ 已验证
DOI
高影响因子
CURRENT ORGANIC SYNTHESIS
·
2024
·Vol. 21
·期 1
·47-60
·
IF 1.7
Zhang Cuizhi,Fan Yanchao,Wang Sijia,Liu Shaojie,Chu Xiaomeng,Tang Erjun
Introduction: L-proline is an efficient chiral small-molecule organocatalyst for the direct asymmetric aldol reaction between unmodified acetone and a variety of aldehydes. Methods: However, it is difficult to separate from the reaction medium for reuse. In this work, polyacrylic
acid (PAA) supported The acylation reaction between L-hydroxyproline and PAA prepared lproline (P(AA-co-PA)) catalysts with various catalyst loadings. Fourier characterized them transforms infrared spectroscopy, nuclear magnetic resonance spectrum, gel permeation chromatography and thermogravimetry
analysis. Results: These macromolecular catalysts were used to catalyze acetone and benzaldehydes' direct asymmetric aldol reaction. The influence of the catalyst structure on the catalytic performance was studied, and the reaction conditions were optimized. Conclusion: The results
showed that P(AA-co-PA) with 50 mol% catalyst loading had excellent catalytic performance, much higher than that of L-proline and L-hydroxyproline. Its recovery was achieved by simple filtration. After being reused 7 times, its catalytic performance was still higher than that of L-proline.
研究领域:
有机化学
·
催化化学
✓ 已验证
DOI
高影响因子
BIORESOURCE TECHNOLOGY
·
2022
·
IF 11.889
Xin-Yue Chen,Hui-Zhong Sun,Bin Qiao,Chang-Hao Miao,Zheng-Jie Hou,Shu-Jing Xu,Qiu-Man Xu,Jing-Sheng Cheng
The application of antibacterial lipopeptides is limited by high cost and low yield. Herein, the exogenous L-proline significantly improved lipopeptide production by Bacillus amyloliquefaciens HM618. A recombinant Corynebacterium glutamicum producing high levels of proline using genetically modifying proB and putA was used to establish consortium, to improve lipopeptide production of strain HM618. Compared to a pure culture , the levels of iturin A, fengycin, and surfactin in consortium reached 67.75, 39.32, and 37.25 mg L -1 , respectively, an increase of 3.19-, 2.05-, and 1.63-fold over that produced by co-cultures of B. amyloliquefaciens and recombinant C. glutamicum with normal medium. Commercial amylase and recombinant Pichia pastoris with a heterologous amylase gene were used to hydrolyze kitchen waste. A three-strain consortium with recombinant P. pastoris and C. glutamicum increased the lipopeptide production of strain HM618 in medium containing KW. This work provides new strategies to improve lipopeptide production by B. amyloliquefaciens.
研究领域:
微生物学
·
生物技术
✓ 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）