Catalysis Science & Technology
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2022
·Vol. 13
·期 3
·684-693
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IF 6.177
Lian Xu,Dan Nie,Bing-Mei Su,Xin-Qi Xu,Juan Lin
The synthesis of chloramphenicol, a kind of amphenicol antibiotic with broad-spectrum antibacterial activity, is challenging due to its stereochemistry. Here, we have designed a four-step chemoenzymatic strategy, including a biocatalytic step mediated by L-threonine transaldolase from Pseudomonas sp. (PsLTTA) to convert 4-nitrobenzaldehyde (1) to (2S,3R)-2-amino-3-hydroxy-3-(4-nitrophenyl)propanoic acid (2) followed by a three-step chemical reaction to obtain chloramphenicol. A rational design of PsLTTA was devised by reshaping the substrate binding pocket and substrate access channel, resulting in the best variant PsLTTA-N35A/C57I/F59A/H69F (PsLTTA-Mu9), which achieved a 7.1-fold higher yield of 2 than wild-type PsLTTA. After coupling with ScADH/CbFDH to remove the byproduct acetaldehyde and optimizing the reaction conditions, the whole-cell catalyst BL21(PsLTTA-Mu9/ScADH/CbFDH) could synthesize 200 mM of 2 in four hours with 99% conversion and 97.7% de, delivering the highest time–space yield (11.3 g L−1 h−1) ever reported. Finally, the chemoenzymatic approach was applied for the gram-scale synthesis of 5 with a high overall yield (54%). The success of this strategy demonstrates the great advantage of the chemoenzymatic approach in the asymmetric synthesis of chloramphenicol and may contribute to its industrial synthesis.
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INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2022
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IF 8.025
Peng Zhou,Xiangzhou Li,Zhi Jiang,Jun Zhou,Guang He,Limin Qu
In this paper, a kind of superabsorbent resin (SAR) with superior quality for hygiene products was developed using Fructus Aurantii Immaturus pectin (FAIP) from Citrus aurantium L.. FAIP-g-AM/AMPS SAR was established by free radical graft co -polymerization with FAIP as skeleton structure, N, N′-Methylene-bis (acrylamide) (MBA) as the cross-linker. Meanwhile, the functional monomers of acrylamide (AM) and 2-acrylamido-2-methylpropane sulfonic acid (AMPS) were introduced. The structure and morphology of FAIP-g-AM/AMPS were characterized by FTIR , 13 C NMR, XRD, SEM and TG-DSC analysis. The results confirmed that the AFIP-g-AM/AMPS SAR was successfully prepared, which exhibited a three-dimensional (3D) network structure and an excellent thermal stability . The absorption and retention capacity of FAIP-g-AM/AMPS was comparable to or even better than commercial diapers and sanitary napkins. Significantly, FAIP-g-AM/AMPS itself exhibited excellent antibacterial and safety. FAIP-g-AM/AMPS has an inhibition ratio of 97.1 % for Escherichia coli ( E. coli ) and 98.5 % for Staphylococcus aureus ( S. aureus ), and was non-irritating and non-allergic to the skin. In addition, FAIP-g-AM/AMPS presented amazing biodegradability and a weight loss reached 37.1 % after 30 days by soil burial test. The research provides a safe and high-performance SAR, which expected to be used in hygiene products such as baby diapers, adult incontinence pads and sanitary napkins.
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FOOD RESEARCH INTERNATIONAL
·
2022
·
IF 7.425
Zi Ye,Zhixun Shang,Shiyao Zhang,Meiqi Li,Xuetin Zhang,Hongbing Ren,Xiaosong Hu,Junjie Yi
Pickled chili pepper ( Capsicum frutescens L.), a traditional Chinese fermented vegetable product, is favored by consumers because of its unique flavor. Microbial succession is the main factor affecting the development of the typical flavor of pickled chili pepper. This study investigated the dynamics of flavor changes (mouthfeel sensation, taste properties, and aroma profile) and microbial diversity (bacterial and fungal communities) during the industrial-scale fermentation of pickled chili pepper. Results revealed that during fermentation, the hardness and pungency of pickled chili pepper decreased significantly ( P < 0.05), whereas organic acids, free amino acids, and volatiles (especially terpenes, alcohols, and aldehydes) increased significantly ( P < 0.05). Lactobacillus and Candida species, specifically, Lactobacillus brevis and Candida sp. F15, dominated in pickled chili pepper. Correlation analysis indicated that the dominant bacterial ( Lactobacillus versmoldensis and L. brevis ) and fungal ( Colletotrichum simmondsii and Cladosporium tenuissimum ) species had a high positive correlation with volatile compounds (e.g., aldehydes, terpenes, and esters).
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JOURNAL OF POLYMER RESEARCH
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2022
·Vol. 29
·期 5
·1-12
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IF 3.061
Hu Chunwang,Wei Hongliang,Hua Bingyan,Zhang Yaqi,Wang Gang,Shen Yanmin,Niu Yongsheng
Drug- controlled delivery can effectively avoid excessive drug use and improve the utilization rate of drugs and reduce the harm of drugs to the body. Herein, a novel poly(α-L-lysine)-based interpenetrating network (IPN) hydrogel with thermo/pH sensitivity was fabricated by synchronous free-radical polymerization and amine-anhydride click reaction in one pot. The hydrogels were characterized by FTIR, X-ray diffraction (XRD), and scanning electron microscopy (SEM). The IPN hydrogels well integrated thermo-sensitivity and pH-sensitivity of two single-network hydrogels. The experimental results showed that the IPN hydrogel exhibited different swelling properties at different pH and temperatures. Finally, the anticancer drug 5-fluorouracil (5-Fu) was chosen as a model drug to investigate the controlled release behavior of the hydrogel. The study showed that the release behavior of 5-Fu from the IPN hydrogel depended on temperature and pH changes, which followed the Korsmeyer-Peppas kinetic model. The IPN hydrogel is expected to be a candidate material for drug sustained-release carriers.
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SCIENCE OF THE TOTAL ENVIRONMENT
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2022
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IF 10.753
Yue Cai,Binbin Yuan,Xiaoyue Ma,Guodong Fang,Dongmei Zhou,Juan Gao
Nano-enabled foliar-application could be an ideal strategy for advancing agricultural productivity. However, it remains largely unknown whether they inhibit or promote the uptake of pollutants. Here, we systematically examined how foliar applying SiO 2 nanoparticles (nSiO 2 ) and ZnO nanoparticles (nZnO) (20 nm, 100 mg·L −1 ), influence polycyclic aromatic hydrocarbons (PAHs) uptake in 4-week-old amaranth ( Amaranthus tricolor L.). Results showed that foliar application of nSiO 2 or nZnO enhanced amaranth biomass by 20.2–26.4% but decreased PAHs bioaccumulation in leaves by 20.4–54.9% after 7-d incubation. Changes regarding amino acid-related pathways (alanine/aspartate/glutamate metabolism and arginine biosynthesis) and energy maintenance pathways (TCA cycle) were observed in amaranth leaves after foliar application of nSiO 2 and nZnO. Specific PLS-DA analyses with total PAHs uptake as the biological endpoint showed that the contents of PAHs positively correlated with valine ( R 2 = 0.799) and tyrosine ( R 2 = 0.789), but negatively correlated with D-tagatose ( R 2 = 0.805) and L-gulonolactone ( R 2 = 0.877), indicating greater oxidant stress under higher PAHs level. We propose that mechanisms of declined uptake of PAHs involve the biomass-dependent dilute effect and activation of biological response against PAHs accumulation. These findings provide a prospective vision on how nano-enabled foliar-application alleviates PAH-enriched environmental burden while producing higher-yield agricultural products, especially for low toxic and biocompatible nSiO 2 .
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JOURNAL OF COLLOID AND INTERFACE SCIENCE
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2022
·
IF 9.965
Jingxuan Pei,Yibo Sun,Xiang Yu,Zhenfei Tian,Shuting Zhang,Songbo Wei,Yanfang Zhao,Rabah Boukherroub
Development of reliable sensing strategy combining surface-enhanced Raman scattering (SERS) and surface-assisted laser desorption/ionization-mass spectrometry (SALDI-MS) is of significant interest to distinguish cysteine enantiomers in body fluid for understanding their physiological roles and toxicity hazards. In this work, a SERS/SALDI-MS dual-mode sensing platform of gold nanoparticles (Au NPs) decorated holey carbon nitride (hg-C 3 N 4 ) was fabricated for sensitive detecting cysteine. The designed Au@hg-C 3 N 4 matrix featured a uniform distribution of Au NPs with the help of anchoring effect of hg-C 3 N 4 holey structure, which was conducive to produce highly repeatable signals. Moreover, the combination of Au NPs and holey g-C 3 N 4 endowed this matrix with superior enrichment capacity, enhanced charge transfer and strong UV absorption. These merits allowed the matrix to acquire high sensitivity and enhanced reproducibility for l -cysteine by means of SERS/SALDI-MS. Likewise, reliable detection of l -cysteine and efficient recognition of d -cysteine in human serum jointly revealed its prospect for detecting cysteine enantiomers in body fluids. This work offers a reliable SERS/SALDI-MS strategy for determining L/D-cysteine enantiomers, and the designed Au@hg-C 3 N 4 matrix becomes a potential application candidate for selective detection of bio-enantiomers.
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FOOD CHEMISTRY
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2022
·
IF 9.231
Ming Nie,Lu Wang,Shengmin Lu,Yangguang Wang,Meiyu Zheng,Zhongxiang Fang
The protective effects of three amino acids ( l -phenylalanine, l -tryptophan and l -methionine) on the stability of bayberry anthocyanins were investigated. The anthocyanin stability under constant illumination (5000 Lux, 50 Hz) or in the presence of ascorbic acid were evaluated by degradation kinetic parameters, and the interaction between l -methionine and cyanidin-3-O-glucoside (C3G) in a model beverage system was analyzed using Fourier transform infrared spectroscopy, 1H nuclear magnetic resonance, X-ray diffraction, molecular docking, and molecular dynamics simulation. Results indicated that the three amino acids significantly reduced the degradation rate of bayberry anthocyanins (p < 0.05), with the most effect by l -methionine. l -methionine could bind to C3G via hydrogen bonds and Van der Waals forces. This study suggested that l -methionine could well protect anthocyanin against degradation in the aqueous solution and have the potential to be used as a co-pigment to improve the sensory property and extend the shelf life of anthocyanin rich berry products.
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FOOD CHEMISTRY
·
2022
·
IF 9.231
Zhimin Zhang,Miao Liang,Binshan Liu,Yajian Wu,Rui Wang,Yuping Liu
To characterize the key odorants in ripe Capparis spinosa L. fruit (RCF) and to investigate changes in the odorants after storage, volatiles were captured by both solid-phase microextraction and solvent extraction combined with solvent-assisted flavor evaporation; a total of 22 aroma-active regions were detected in the isolates by gas chromatography–olfactometry. Of 19 odor-active compounds identified positively, 13 odorants were found in RCF for the first time; their flavor dilution factors ranging from 1 to 512 were measured by an aroma extract dilution assay. Eleven odorants were determined as the key odorants by stable isotope dilution analysis, odor activity value (OAV) calculation, and recombination experiments. To further investigate the changes in odorants after storage, their concentrations and OAVs were determined. The results showed that the number of key odorants did not change before and after storage, but the concentrations of octanoic acid, sotolon, and 3-methylbutanoic acid increased markedly.
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FOOD SCIENCE AND TECHNOLOGY RESEARCH
·
2021
·
IF 0.668
Shirong Huang,Huan Liu,Sinian Yan,Dongfang Chen,Xin Mei
Here, the changes in phenolic composition and antioxidant activities (ABTS, DPPH, and FRAP) of raw and pickled cowpea green pod during in vitro simulated gastrointestinal digestion (GID) were investigated. The inhibitory activities of the undigested and digested samples towards α-amylase, α-glucosidase and lipase were determined. Results revealed that total phenolic (TP) and flavonoid (TF) contents of both raw and pickled samples were increased after gastric and intestinal digestion, and the pickled sample had lower TP and TF content after each digestion phase. A similar trend was observed for antioxidant activities, which were significantly correlated with TP and TF contents (p < 0.05). Seven phenolic compounds were identified and quantified by HPLC-DAD. Their contents were affected by digestion and pickling, and raw cowpea pod had higher contents before and after GID. Inhibitory effects towards α-amylase, α-glucosidase and lipase were increased for raw cowpea pod after GID. Pickled cowpea pod also showed an increased inhibitory activity towards lipase, while no activity towards α-amylase and α-glucosidase. Raw cowpea pod had higher inhibitory effects towards α-amylase, α-glucosidase and lipase than the pickled one at each digestion phase. Our results showed that pickling process reduced the health-promoting properties of cowpea green pod.
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FOOD CHEMISTRY
·
2021
·
IF 7.514
Li-Xin Ma,Xu-Hui Huang,Jie Zheng,Liu Dong,Jia-Nan Chen,Xiu-Ping Dong,Da-Yong Zhou,Bei-Wei Zhu,Lei Qin
Blue mussel ( Mytilus edulis L.) is a popular, nutritional, and tasty mollusk. To better understand the composition of nutrients and improve further processing of the mussels, metabolomic approaches were used to analyze the free amino acids, 5ʹ-nucleotides, and lipid compositions of different tissues. Our results showed that the viscera and gonad were rich in glutamine and glycine. Adenosine 5ʹ-monophosphate, uridine 5ʹ-monophosphate, guanosine 5ʹ-monophosphate, and inosine 5ʹ-monophosphate were abundant in the mantle, foot, and adductor muscle. Three main types of lipids, phospholipids (PLs), glycerides, and fatty acids (FAs), were semi-quantified. PLs were mainly distributed in the gonad of male mussels and viscera, gonad, and mantles of female mussels. FAs were relatively high in the viscera of males and in the gonad and viscera of females. The viscera of females were rich in phosphatidylcholine, such as 16:0/22:6 and 16:0/20:5. Triglycerides were the key lipids for distinguishing different tissues, especially 16:0/18:1/18:3 and 16:0/18:4/20:5.
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TOXICOLOGY
·
2021
·
IF 4.221
Yaodong Yi,Liping Li,Feifeng Song,Ping Li,Mingyang Chen,Shixin Ni,Hengbin Zhang,Hui Zhou,Su Zeng,Huidi Jiang
Oxaliplatin (OXA) is a third-generation platinum drug; however, its application is greatly limited due to the severe peripheral neurotoxicity. This study aims to confirm the transport mechanism of OXA and to explore whether L-tetrahydropalmatine (L-THP) would alleviate OXA-induced peripheral neurotoxicity by selectively inhibiting these uptake transporters in vitro and in vivo . Our results revealed that organic cation transporter 2 (OCT2), organic cation/carnitine transporter 1 (OCTN1) and organic cation/carnitine transporter 2 (OCTN2) were involved in the uptake of OXA in dorsal root ganglion (DRG) neurons and mitochondria, respectively. L-THP (1−100 μM) reduced OXA (40 μM) induced cytotoxicity in MDCK-hOCT2 (Madin–Darby canine kidney, MDCK), MDCK-hOCTN1, MDCK-hOCTN2, and rat primary DRG cells, and decreased the accumulation of OXA in above cells and rat DRG mitochondria, but did not affect its efflux from MDCK-hMRP2 cells. Furthermore, Co-administration of L-THP (5–20 mg/kg for mice, 10–40 mg/kg for rats; twice a week, iv or ig ) attenuated OXA (8 mg/kg for mice, 4 mg/kg for rats; twice a week, iv ) induced peripheral neurotoxicity and reduced the platinum concentration in the DRG. Whereas, L-THP (1−100 μM for cells; 10–20 mg/kg for mice) did not impair the antitumour efficacy of OXA (40 μM for cells; 8 mg/kg for mice) in HT29 tumour-bearing nude mice nor in tumour cells (HT29 and SW620 cells). In conclusion, OCT2, OCTN1 and OCTN2 contribute to OXA uptake in the DRG and mitochondria. L-THP attenuates OXA-induced peripheral neurotoxicity via inhibiting OXA uptake but without impairing the antitumour efficacy of OXA. L-THP is a potential candidate drug to attenuate OXA-induced peripheral neurotoxicity.
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JOURNAL OF MATERIALS SCIENCE
·
2020
·Vol. 56
·期 1
·731-745
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IF 3.553
Wang Jingguang,Gao Huichang,Hu Yang,Zhang Naiyue,Zhou Wuyi,Wang Chaoyang,Binks Bernard P.,Yang Zhuohong
Abstract Biocompatible and bioactive scaffolds with multiscale porosity, shape memory effect and drug delivery performance are highly promising in bone tissue engineering applications within the approach of minimally invasive surgical implantation. In this study, we report an effective method to fabricate multiscale porous bioactive (MPB) scaffolds with shape memory effect by freeze drying of 3D printed high internal phase Pickering emulsion (Pickering HIPE) templates stabilized by hydrophobically modified hydroxyapatite and silica nanoparticles. MPB scaffolds containing a shape memory polymer matrix of poly(D,L-lactide-co-trimethylene carbonate) display high porosity and fully interconnected filament networks with multiscale pore structures. The in vitro biomineralization study verifies that MPB scaffolds are bioactive with the apatite formation ability. The thermal property testing shows that the glass transition temperature of MPB scaffolds is easily tuned to fall between 45.9 and 49.1 °C by varying the HIPE composition. Moreover, MPB scaffolds exhibit observable shape memory properties with fast shape recovery. The antibacterial drug enrofloxacin can be efficiently loaded into MPB scaffolds and then released in a sustained manner displaying effective antimicrobial effect. Furthermore, cell culture assays confirm that MPB scaffolds could sustain the cell growth, proliferation and osteogenic differentiation, indicating the cytocompatibility and osteoinduction activity of MPB scaffolds. Therefore, combining freeze drying with 3D printing of Pickering HIPE templates paves the way towards MPB scaffolds with shape memory effect, which are promising as minimally invasive implantation scaffolds in bone tissue engineering applications. Graphic Abstract
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