SEPARATION AND PURIFICATION TECHNOLOGY
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2021
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IF 7.312
Xuefeng Xiao,Yongjun Sun,Jianwen Liu,Huaili Zheng
Two bioflocculants of starch-graft-P[acrylamide-acrylic acid] (SAA) and starch-graft-P[acrylamide-2-acacrylamido-2-methyl-1-propanesulfonic acid] (SAS) are designed for the flocculation–chelation of heavy metals. The successful polymer synthesis is confirmed through physicochemical characterization. SAA and SAS are used to remove Cu(II), Zn(II), and Ni(II) from simulated wastewater and Ni(II) from actual electroplating wastewater. The removal efficiencies for Cu(II), Zn(II), and Ni(II) in the simulated wastewater by SAA and SAS are more than 80.00%, whereas those for Ni(II) are more than 90.0% in the Ni-containing electroplating wastewater at the optimal condition. Flocculation experiments reveal that the sulfonate structure of SAS is highly conducive to improve flocculation efficiency. SAA and SAS have high selectivities for Cu(II) in the simulated water sample with mixed heavy metal. Finally, the 3E (i.e., environmental impact, economic benefit, and energy consumption) triangular evaluation model is established to evaluate the flocculation experiments for the removal of heavy metal ions using SAA and SAS.
研究领域:
环境科学
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材料科学
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产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2025
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IF 8.5
Kai Yang,Zhenjie Tang,Chong Zhang,Ruide Zhang,Sheng Hu,Changjiang Lv,Jun Huang,Jiaqi Mei,Weirui Zhao,Lehe Mei
Salvianic acid A (SAA) is a catechol compound known for its diverse physiochemical functions and has significant applications in the food and pharmaceutical industries. 4-Hydroxyphenylacetate-3-hydroxylase (4HPA3H) is a critical enzyme for SAA biosynthesis, and improving its activity towards p -hydroxyphenyllactate acid (4HPLA) is essential for highly efficient SAA production in stable biosynthetic pathways. To address this, the distal site and loops of the substrate pocket were modified to improve 4HPA3H catalytic activity towards 4HPLA using computer-aided molecular modification methods. As a result, we identified and mutated two critical sites in Ec HpaB, a 4HPA3H monooxygenase from Escherichia coli : T398, a substrate loop site, and M205, a distal site. The mutants M205F, T398S, and M205F/T398S enabled 2.51-, 2.07-, and 2.20-fold increases in catalytic efficiency ( k cat / K m towards 4HPLA), respectively. Molecular dynamics simulations showed that the overall decreased flexibility of the substrate pocket loop in Ec HpaB might help improve the enzyme's catalytic activity for 4HPLA. Owing to the T398 site in the substrate pocket coming from another monomer, molecular modification of Ec HpaB with multi-monomer interactions was also worthy of attention. These findings not only enhanced the biosynthetic efficiency of SAA but also provided insights into enzyme distal site modification and the engineering of multi-monomer enzymes.
研究领域:
生物化学
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酶工程
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计算生物学
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产品关联
DOI
PubMed
高影响因子
Materials Research Express
·
2024
·Vol. 11
·期 8
·085310
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IF 1.8
Yunhai Shi,Kai Lu,Zejian He,Yulong Chen,Mi Zhou
Water reducing agent as an important admixture. It is used to decrease the initial water content in cement paste, improving its fluidity. Polycarboxylic acid water reducing agent (PCE) is a high-performance type with advantages such as low dosage, high water reduction rate, environmental friendliness, and a simple synthesis process. In this study, the third monomer (TPEG-SAA-SHES) was synthesized by modifying isopentenol polyoxyethylene ether (TPEG) with sodium hydroxyethyl sulfonate (SHES). Subsequently, a modified ether polycarboxylic acid-based water reducing agent (PCE-S) was synthesized with TPEG and acrylic acid (AA). The experimental conditions for the synthesis of PCE-S were optimized through orthogonal tests. The synthesized PCE-S showed a certain degree of improvement in the initial net slurry flow compared to PCE, with a maximum enhancement of 19.64%. The adsorption increased by 18.25% when the TSS dosage was 5%. PCE-S enhances the hydration products of cement, increasing the compactness of the structure. The product is environmentally friendly, safe, and durable, effectively reducing the dosage of additives and helping to cut costs. It lays the foundation for the next industrialized mass production.
研究领域:
建筑材料化学
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高分子材料合成
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产品关联
DOI
高影响因子
CHEMICAL PHYSICS
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2025
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IF 2.4
Wenchao Ma,Na Du,Wanguo Hou
Prediction of surface tension and surface composition of multicomponent liquid mixtures remains challenging. A predictive model, called the “surface aggregation adsorption” (SAA) model, was proposed recently, but its applicability needs to be examined, especially for the monophasic solutions containing immiscible components. In this work, the surface tensions of binary and ternary solutions consisting of isopropanol ( i PrOH), water, and n -decane (DA) or n -tetradecane (TDA) were determined. Based on the SAA model, the model parameters of the binary ( i PrOH–water or DA or TDA) solutions were first estimated, and then used to predict the surface tension and composition of the ternary ( i PrOH–water–DA or TDA) solutions. The predicted surface tension values for the ternary solutions are well consistent with their experimental ones. Importantly, the so-obtained information on surface compositions can provide a better understanding of the surface adsorption behavior.
研究领域:
物理化学
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材料科学
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产品关联
DOI
高影响因子
Bioresources and Bioprocessing
·
2023
·Vol. 10
·期 1
·1-14
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IF 4.6
Yang Jiahui,Wei Wanqing,Gao Changzheng,Song Wei,Gao Cong,Chen Xiulai,Liu Jia,Guo Liang,Liu Liming,Wu Jing
Salvianic acid A (SAA), used for treating cardiovascular and cerebrovascular diseases, possesses several pharmacological properties. However, the current methods for the enzymatic synthesis of SAA show low efficiency. Here, we constructed a three-enzyme cascade pathway in Escherichia coli BL21 (DE3) to produce SAA from l-dihydroxyphenylalanine (L-DOPA). The phenylpyruvate reductase (LaPPR) from Lactobacillus sp. CGMCC 9967 is a rate-limiting enzyme in this process. Therefore, we employed a mechanism-guided protein engineering strategy to shorten the transfer distances of protons and hydrides, generating an optimal LaPPR mutant, LaPPRMu2 (H89M/H143D/P256C), with a 2.8-fold increase in specific activity and 9.3-time increase in kcat/Km value compared to that of the wild type. Introduction of the mutant LaPPRMu2 into the cascade pathway and the optimization of enzyme levels and transformation conditions allowed the obtainment of the highest SAA titer (82.6 g L−1) ever reported in vivo, good conversion rate (91.3%), excellent ee value (99%) and the highest productivity (6.9 g L−1 h−1) from 90 g L−1 L-DOPA in 12 h. This successful strategy provides a potential new method for the industrial production of SAA.
研究领域:
生物化学
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生物技术
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酶学
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制药
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产品关联
DOI
PubMed
高影响因子
MOLECULAR PHARMACEUTICS
·
2023
·
IF 4.9
Qingfa Tang,Yao Chen,Yusheng Zhang,Kewei Wang,Li Liu,Dongmei Pan,Qiang Liu,Cuiping Jiang
Tanshinone IIA (TS-IIA) and salvianic acid A (SAA) are the main pharmacological active constituents of Danshen, which exhibit potent effects on atherosclerosis. A combination of TS-IIA and SAA might exert a synergistic antiatherosclerotic effect. However, the opposite solubility profiles of TS-IIA and SAA might lead to difficulty in achieving a synergistic combined effect of the two active components. Therefore, in this work, we fabricated a ROS-responsive prodrug micelle for the codelivery of TS-IIA and SAA (TS-IIA-PM) by self-assembling amphiphilic block copolymer PEG5000-SAA/PLA10000-APBA. The amphiphilic polymer was characterized by 1H NMR, FTIR, and alizarin red S competition tests. The ROS responsiveness of TS-IIA-PM was evidenced by time-course monitoring of particle size and morphology changes and drug release behavior in the presence of 1 mM H2O2. We found TS-IIA-PM was stable according to its critical micelle concentration and the unchanged particle sizes in 10% FBS for 7 days. The results of in vitro and in vivo tests revealed that TS-IIA-PM was safe and biocompatible. Furthermore, it was observed that TS-IIA and prodrug micelle could produce synergistic antiatherosclerotic effect based on the results of the antioxidant study, which was further confirmed by a series of pharmocodynamics studies, such as in vitro DiI-oxLDL uptake study, oil red O staining, cholesterol efflux study, inflammatory cytokine analysis, in vivo CD68 immunostaining, and lipid disposition staining studies. Collectively, TS-IIA-PM holds great potential for the safe and efficient codelivery of TS-IIA and SAA for synergistic antiatherosclerosis.
研究领域:
药学
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纳米技术
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心血管疾病
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药物递送系统
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生物医学工程
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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）