JOURNAL OF FOOD PROCESSING AND PRESERVATION
·
2020
·Vol. 44
·期 9
·e14691
·
IF 1.405
Liyang Wei,Changhong Liu,Jinjin Wang,Shoaib Younas,Huanhuan Zheng,Lei Zheng
In the current study, fresh-cut broccoli was soaked in melatonin solution before cold storage (4°C, 95% RH) for 25 days. The results indicated that 100 µM melatonin treatment inhibited the increase of L * and b * values and retained higher hue angle, total chlorophyll content, and fresh weight during storage. Furthermore, 100 µM melatonin treatment obviously increased antioxidant contents including ascorbic acid, total phenols, and flavonoids, and enhanced the antioxidant activity of florets. Individual phenolic compounds including epicatechin, rutin, and quercetin were positively influenced by melatonin treatment. Superoxide dismutase (SOD), ascorbate peroxidase (APX), and catalase (CAT) activities were obviously enhanced by 100 µM melatonin treatment whereas peroxidase (POD) activity was significantly reduced. Moreover, florets treated with melatonin exhibited lower malondialdehyde (MDA), H 2 O 2 , and O 2 − levels. Our research concluded that melatonin treatment could be an effective technique for enhancing antioxidant capacity and improving the quality of fresh-cut broccoli during cold storage. Practical applications Fresh-cut fruits and vegetables are more prone to senescence than their intact forms during postharvest storage. Broccoli is a healthy vegetable and has high demands in many countries. In order to reduce economic losses, it is important to delay the senescence and maintain the quality of fresh-cut broccoli during postharvest storage. In this article, 100 µM melatonin treatment was found to significantly enhance antioxidant capacity and delay the senescence of fresh-cut broccoli florets, which maintained the quality of broccoli during cold storage. We believe that melatonin treatment can be applied for the preservation of more fresh-cut fruits and vegetables.
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AAPS PHARMSCITECH
·
2020
·Vol. 21
·期 3
·1-10
·
IF 2.401
Li Xin,Lu Chao,Xia Wenquan,Quan Guilan,Huang Ying,Bai Xuequn,Yu Feiyuan,Xu Qian,Qin Wanbing,Liu Daojun,Pan Xin
Protein drugs were considered to be the first choice to treat many human diseases, but their clinical application was usually limited by their short half-life and lack of validated targeted therapy. Here, a series of folate-functionalized poly(ethylene glycol)- b -(poly(2-aminoethyl-L-glutamate)- g -poly(L-glutamic acid))s (FA-PEG- b -(PELG- g -PLGA)s) were designed as tumor-targeted carriers for cationic protein delivery. Compared with traditional copolymers consisting of PEG and linear charged hydrophilic blocks, FA-PEG- b -(PELG- g -PLGA) with brush-like polyelectrolyte segments were beneficial to improving their electrostatic interactions with loading protein molecules, thus increasing drug-loading stability and protecting encapsulated proteins from degradation. The designed polymer brushes could efficiently encapsulate cytochrome C (CytC), a cationic model protein, to form polyion complex (PIC) micelles with an average particle size of approximately 200 nm. An in vitro drug release study showed that the drug-loading stability of the formed PIC micelles was largely improved. The functionalization of the block copolymer carriers with a targeting folate group enhanced the tumor cell growth inhibition and total apoptotic rates induced by CytC. Our results shed light on the unique advantages of brush-like polymer carriers in delivering cationic proteins, and the poly(L-glutamic acid)-based linear-brush diblock copolymers could be applied as a versatile delivery platform for molecular targeting in cancer therapy.
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ENZYME AND MICROBIAL TECHNOLOGY
·
2020
·
IF 3.448
Cun-Duo Tang,Hong-Ling Shi,Yuan-Yuan Jia,Xiang Li,Lin-Feng Wang,Jian-He Xu,Lun-Guang Yao,Yun-Chao Kan
L -Phenylglycine ( L -PHG) is a member of unnatural amino acids, and becoming more and more important as intermediate for pharmaceuticals, food additives and agrochemicals. However, the existing synthetic methods for L -PHG mainly rely on toxic cyanide chemistry and multistep processes. To provide green, safe and high enantioselective alternatives, we envisaged cascade biocatalysis for the one-pot synthesis of L -PHG from racemic mandelic acid. A engineered E. coli strain was established to co-express mandelate racemase, D -mandelate dehydrogenase and L -leucine dehydrogenase and catalyze a 3-step reaction in one pot, enantioselectively transforming racemic mandelic acid to give L -PHG ( e.e. >99 %). After the conditions for biosynthesis of L -PHG optimized by response surface methodology, the yield and space-time yield of L -PHG can reach 87.89 % and 79.70 g·L −1 ·d −1 , which was obviously improved. The high-yielding and enantioselective synthetic methods use cheap and green reagents, and E. coli whole-cell catalysts, thus providing green and useful alternative methods for manufacturing L -PHG.
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INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2020
·
IF 3.573
Congshu Feng,Yun Chen,Jun Shao,Haoqing Hou
Blending of poly(l-lactide) (PLLA) and poly(d-lactide) (PDLA) would produce polylactide stereocomplex crystallites (PLA SC). In the PLLA/PDLA specimens prepared by solution mixing or melt blending, the isomeric polymers were mixed in the molecular level. When the distance of these isomers increased, the crystallization behaviors of PLLA/PDLA were not clear yet. In this study, PLLA/PDLA blends were prepared by different electrospinning methods, i.e., spinning by mixed solution (DL-A), side-by-side mode (DL-B), and double spinnerets (DL-C). Results revealed that the distances between isomeric molecules increased in the order of DL-A, DL-B, and DL-C, and this distance influences the phase transition and subsequently crystallization behaviors. In the DL-A, the homochiral crystallites (HC) developed at first, and then SC formed in the specimen with lower content of PDLA. The formation of SC was observed at first, and less or no content of HC was developed with higher content of PDLA. For the DL-B group, the formation of HC was observed at ∼100 °C, and the SC were produced around 140 °C irrespective of composition. More content of SC was produced during or after melting of HC. When referring to the DL-C group, the HC developed at the first stage, and the SC were produced during or after melting of PLA HC. In addition, the SC that developed in the three groups have different nucleation efficiencies for the subsequent formation of HC. The nucleation efficiency increased in the order of DL-A < DL-B < DL-C, and these results hinted that not only the content but also the distribution of SC affects the formation of HC.
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DESIGNED MONOMERS AND POLYMERS
·
2020
·
IF 1.75
Yunpeng Min,Hang Zhang,Huiru Wang,Yimin Song
This work aims to study the construction of reverse aspirin-loaded micelles prepared from amphiphilic PEG-PLA-SA triblock copolymers and the optimization of the preparation process. Using polyethylene glycol (PEG) as the initiator, ring-opening polymerization of L-lactide (L-LA) was used to prepare PEG-PLA diblock copolymers. Final product PEG-PLA-SA triblock copolymers were prepared by the reaction of stearic acid (SA) and PEG-PLA catalyzed by 4-dimethylaminopyridine (DMAP) and N,N’-Dicyclohexylcarbodiimide (DCC). Fourier transform infrared spectrometer (FT-IR) was used to characterize the product structure. PEG-PLA-SA triblock copolymers self-assembled in toluene/ethanol/water system to form reverse micelles, which could encapsulate aspirin into a hydrophilic core. Dynamic light scattering (DLS) and transmission electron microscopy (TEM) were used to determine the size and morphology of reverse micelles. The results showed that the reverse micelles are spherical, with a particle size of less than 70 nm. Response surface analysis method was applied to optimize the preparation process of PEG-PLA-SA. In vitro drug release was achieved by embedding reverse aspirin-loaded micelles in the biocompatible membrane in phosphate buffer saline (PBS) at 37°C. In the first 8 h, the drug release rate of the triblock copolymers was slower than that of the diblock copolymers. After 8 h, the drug release rate of both tended to be flat. The stability of aspirin-loaded reverse micelles was studied through accelerated test. These results indicate that reverse micelle PEG-PLA-SA may be a promising carrier for hydrophilic drugs like aspirin.
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MICROCHEMICAL JOURNAL
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2020
·
IF 3.594
Ming-Zhu Gao,Qi Cui,Li-Tao Wang,Yao Meng,Lian Yu,Yan-Yan Li,Yu-Jie Fu
Green and tailor-made deep eutectic solvents (DESs) coupled with microwave-assisted extraction (MAE) were performed to extract phenolic compounds from mulberry leaves. Among the twelve DESs prepared, Choline chloride/Glycerol (1:2) with 20% water content was more efficient to get high extraction yields of phenolics. Then, several essential parameters of microwave-assisted deep eutectic solvents extraction (DES-MAE) were optimized by single-factor and Box-Behnken design (BBD) experiments. According to the result of optimization, the total extraction yield of target phenolic compounds reached 8.352 mg/g at microwave temperature 66 o C for extracting 18 min with the liquid/solid ratio of 20 mL/g, which was obviously superior to conventional solvent extraction. In addition, the extraction kinetic models confirmed that microwave-assisted extraction was a more efficient extraction technique than ultrasound-assisted extraction and heat-refluxing extraction. Meanwhile, the macroporous resin was utilized to enrich and separate target compounds from DES extracts, and the recovered DES still exhibited a good solvent effect to be applied for re-extraction. Therefore, DES-MAE followed by macroporous resin column chromatography was a green and integrated strategy for the extraction and preparative separation of active ingredients from plant materials.
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JOURNAL OF APPLIED POLYMER SCIENCE
·
2019
·Vol. 137
·期 18
·48646
·
IF 2.188
Meng Ma,Lin Xu,Kai Liu,Si Chen,Huiwen He,Yanqin Shi,Xu Wang
Reactive blending is an innovative method for the improvement of compatibility of polymer blend. In this work, poly ( L -lactic acid) and poly (butylene succinate) (PLLA/PBS) blends were prepared by melt blending to ameliorate the toughness of PLLA. Triphenyl phosphite (TPP) was introduced into the PLLA/PBS blends (80/20 by weight) to enhance their compatibility via reactive blending. The effects of TPP on the morphology and properties of PLLA/PBS blends were studied systematically. The increased torque during melt blending demonstrated that the compatibilizer successfully reacted with PLLA and PBS. The mechanical properties of the blends were exceedingly improved only with 0.5 wt% TPP. A reduction tendency of size of the dispersed phase was observed due to the improvement of compatibility. The DSC and DMA results indicate that the T g of PLLA decreased at a slow rate with the increasing content of TPP. This work provided a simple approach for preparing a kind of high toughed PLLA material. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137 , 48646.
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MICROCHEMICAL JOURNAL
·
2019
·
IF 3.206
Chi Chen,Zhuang Fu,Weiying Zhou,Qiushi Chen,Chenzhao Wang,Lu Xu,Zhibing Wang,Hanqi Zhang
The ionic liquid-immobilized NaY zeolite was prepared by means of impregnation approach and used as the dispersant of matrix solid phase dispersion for the extraction of aloe-emodin, emodin, chrysophanol and physcion in Rheum palmatum L.. High performance liquid chromatography coupled with diode-array detection was used for the separation and determination of target analytes. The ionic liquid-immobilized NaY zeolite was further characterized by SEM, FT-IR, TG, XRD and BET. The experimental parameters, such as type and content of ionic liquid, mass ratio of sample to dispersant, type of washing solvent, and type and volume of elution solvent, were optimized. The results revealed that the prepared ionic liquid-immobilized NaY zeolite presents suitable properties and can be used as the dispersant of matrix solid phase dispersion for the extraction of anthraquinones. Good linearities ( r > 0.9995) were obtained in the range of analyte concentration investigated. The recoveries were 73–98% with the relative standard deviations lower than 6%. Compared with ultrasound-assisted extraction and heat reflux extraction, the present method requires less sample, organic solvent and extraction time. The present method can be applied to the determination of anthraquinones from medicinal plant.
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ACS Sustainable Chemistry & Engineering
·
2022
·
IF 9.224
Zecun Zhang,Xinyu Wan,Baomin Fan,Yuhong Ma,Biao Yang
Poor heat resistance and toughness put some limitations on the applications of poly(lactic acid), one of the most promising eco-friendly polymers. Herein, bimodal poly(l-lactic acid) (PLLA) was prepared by melt-blending high- and low- molecular-weight PLLAs, and the nonisothermal crystallization behavior, heat resistance, and mechanical properties of bimodal PLLA were investigated. Low-molecular-weight PLLA (L-PLLA) improves the crystallization capability of bimodal PLLA. The double melting behavior is reasonably explained by the melting–recrystallization mechanism. Octamethylenedicarboxylic dibenzoylhydrazide, a typical heterogeneous nucleating agent, significantly enhances the crystallization rate and crystallinity of PLLA. The maximum crystallinity of 100% L-PLLA is as high as 54.4%, and the heat deflection temperature (HDT) of the bimodal PLLA containing 95% L-PLLA is up to 151 °C, while the impact strength drops sharply to 17.2 kJ/m2 due to the large crystallite size. d-Sorbitol (DS) exhibits a completely different mechanism from heterogeneous nucleation, that is, a lower crystallization rate but elevated crystallinity and crystallization temperature. The DS-modified sample realizes an excellent balance between heat resistance (HDT up to 136 °C) and impact strength (47.9 kJ/m2) via a self-toughening effect by increasing the crystallinity and reducing the crystallite size.
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FOOD CONTROL
·
2022
·
IF 6.652
Bin Li,Zhirong Wang,Gang Yang,Shan Huang,Shenglan Liao,Kewei Chen,Muying Du,Zsolt Zalán,Ferenc Hegyi,Jianquan Kan
Aflatoxin contamination poses a significant threat to world health and has caused huge economic losses to countries worldwide. The application of volatile organic compounds (VOCs) has emerged as one of the most promising strategies for the prevention and control of fungal contamination. In this work, first, VOCs produced by six lactic acid bacteria (LAB) strains exhibited excellent inhibition activity against the growth of Aspergillus flavus . Then, gas chromatograph-mass spectrometry (GC-MS) identified 32 compounds from captured VOCs of LAB. In addition, partial least square (PLS) analysis revealed that 1-pentanal, 1-pentanol, glycidol, 1- hexanol and 1-heptanol are the compounds most related to antifungal effect in volatile profiles, demonstrating excellent inhibition against A. flavus on both potato dextrose agar (PDA) plates and red pepper powder in next antifungal assay. In vitro experiments revealed 1-pentanal to have the highest antifungal activity of the five VOCs, with a minimal inhibitory concentration (MIC) of 40 μL/L. Scanning electron microscopy (SEM) proved that exposure to 1-pentanal caused A. flavus to exhibit mycelial shriveling and failed conidia formation. Meanwhile, our results showed that fumigation with 1-pentanal had no adverse effect on the quality of red pepper powder. These results indicate that 1-pentanal, identified as the component with the highest antifungal activity in this study, is a promising bio-preservative with the potential to prevent A. flavus contamination of red pepper.
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Journal of Biological Engineering
·
2026
·
IF 6.3
Zhang Zhi,Li Xue,Tang Teng Hua,Yang Wan Jia,Lu Qin Hui,Qiu Yan Yan,Wu Cheng Xin
Background Poly(β-L-malic acid) (PMA) is a biodegradable, biocompatible, and chemically modifiable polymer with broad applications. However, the production of high-molecular-weight, high-purity PMA (hhPMA) has long been constrained by “upstream–downstream linkage obstacles”, resulting in relatively low yield, high cost, and significant environmental burden. To address this issue, we systematically reconstructed the hhPMA production chain, establishing an integrated green chain covering the upstream, midstream, and downstream stages. Results In the upstream stage, we isolated a high-performing strain ( Aureobasidium pullulans 389) for hhPMA from Hevea brasiliensis , which inherently produces high titers of PMA with a dominant high-molecular-weight fraction, and systematically engineered it by reducing by-product biosynthesis, enhancing precursor supply, and balancing cofactors, thereby improving PMA synthesis further. In the midstream stage, a mixed-substrate strategy combining refined sugars with H. brasiliensis sawdust hydrolysate reduced refined carbon and nitrogen inputs by ~ 85% and ~ 100% in shake flasks, and achieved a PMA titer of ~ 260 g/L in a 5-L bioreactor. In the downstream stage, a green separation process integrating CaCO₃ recycling, anion-exchange resin adsorption, and ultrafiltration achieved an overall PMA recovery of > 90%, with > 95% recovery and nearly 99% purity for the ≥ 20 kDa fraction, minimizing Ca-containing wastewater and eliminating solvents. Conclusions This study systematically reconstructed the hhPMA production chain through coordinated upstream strain engineering, midstream mixed-substrate fermentation, and downstream green purification. The reconstructed production chain overcomes “upstream–downstream linkage obstacles,” enabling a more efficient, economical, and green hhPMA manufacturing process from lignocellulosic biomass of H. brasiliensis wood. These findings offer a valuable reference for the production of hhPMA and related organic acids/biopolymers in A. pullulans .
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EUROPEAN JOURNAL OF MEDICINAL CHEMISTRY
·
2016
·
IF 3.902
Han Wang,Renyang Xu,Yongying Shi,Longlong Si,Pingxuan Jiao,Zibo Fan,Xu Han,Xingyu Wu,Xiaoshu Zhou,Fei Yu,Yongmin Zhang,Liangren Zhang,Lihe Zhang,Demin Zhou,Sulong Xiao
Since the influenza viruses can rapidly evolve, it is urgently required to develop novel anti-influenza agents possessing a novel mechanism of action. In our previous study, two pentacyclic triterpene derivatives ( Q8 and Y3 ) have been found to have anti-influenza virus entry activities. Keeping the potential synergy of biological activity of pentacyclic triterpenes and l -ascorbic acid in mind, we synthesized a series of novel l -ascorbic acid-conjugated pentacyclic triterpene derivatives ( 18 – 26 , 29 – 31 , 35 – 40 and 42 – 43 ). Moreover, we evaluated these novel compounds for their anti-influenza activities against A/WSN/33 virus in MDCK cells. Among all evaluated compounds, the 2,3- O , O -dibenzyl-6-deoxy- l -ascorbic acid-betulinic acid conjugate ( 30 ) showed the most significant anti-influenza activity with an EC 50 of 8.7 μM, and no cytotoxic effects on MDCK cells were observed. Time-of-addition assay indicated that compound 30 acted at an early stage of the influenza life cycle. Further analyses revealed that influenza virus-induced hemagglutination of chicken red blood cells was inhibited by treatment of compound 30 , and the interaction between the influenza hemagglutinin (HA) and compound 30 was determined by surface plasmon resonance (SPR) with a dissociation constant of K D = 3.76 μM. Finally, silico docking studies indicated that compound 30 and its derivative 31 were able to occupy the binding pocket of HA for sialic acid receptor. Collectively, these results suggested that l -ascorbic acid-conjugated pentacyclic triterpenes were promising anti-influenza entry inhibitors , and HA protein associated with viral entry was a promising drug target.
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