JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
·
2024
·
IF 5.7
Qilin Yang,Yitao Bai,Shuangping Liu,Xiao Han,Tiantian Liu,Dongna Ma,Jian Mao
Elevated levels of biogenic amines (BAs) in fermented food can have negative effects on both the flavor and health. Mining enzymes that degrade BAs is an effective strategy for controlling their content. The study screened a strain of Lactobacillus hilgardii 1614 from fermented food system that can degrade BAs. The multiple copper oxidase genes LHMCO1614 were successfully mined after the whole genome protein sequences of homologous strains were clustered and followed by homology modeling. The enzyme molecules can interact with BAs to stabilize composite structures for catalytic degradation, as shown by molecular docking results. Ingeniously, the kinetic data showed that purified LHMCO1614 was less sensitive to the substrate inhibition of tyramine and phenylethylamine. The degradation rates of tyramine and phenylethylamine in huangjiu (18% vol) after adding LHMCO1614 were 41.35 and 40.21%, respectively. Furthermore, LHMCO1614 demonstrated universality in degrading tyramine and phenylethylamine present in other fermented foods as well. HS-SPME-GC-MS analysis revealed that, except for aldehydes, the addition of enzyme treatment did not significantly alter the levels of major flavor compounds in enzymatically treated fermented foods (p > 0.05). This study presents an enzymatic approach for regulating tyramine and phenylethylamine levels in fermented foods with potential applications both targeted and universal.
研究领域:
微生物学
·
食品安全
·
酶学
✓ 已验证
DOI
PubMed
高影响因子
FIBERS AND POLYMERS
·
2021
·Vol. 22
·期 9
·2440-2446
·
IF 2.153
Ju Lin-Xin,Li Fan,Ning Xin,He Hong-Wei,Zhou Rong
As a natural cellulose fiber, kapok fiber is much easier to degrade due to its thin wall structure of fiber in the process of storage and use. In this work, a finishing modification was designed and developed to prevent kapok fiber from degradation. Dopamine was polymerized in situ and deposited on the surface of kapok fiber, which was operated in the mixed solvents of ethanol:water (1:1 in volume) to overcome the strong buoyancy. Polyethyleneimine (PEI) was introduced to assist dopamine polymerization and improve the load rate. An optimum dosage, 1.0 g/ l of PEI could afford the highest loading rate of 32.1% of polydopamine (PDA), and remarkably improve loading fastness. As a multi-amino polymer, PEI could reduce Ag + and chelate with metal silver (Ag). The PDA/Ag covered kapok fiber and nonwovens showed good antibacterial activity and better mechanic strength, which would be more suitable for durable oil absorption and sound absorption materials than pure kapok fiber.
研究领域:
材料科学
·
纺织工程
·
生物学
✓ 已验证
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2017
·Vol. 41
·期 16
·7924-7931
·
IF 3.269
Aiping Gao,Yiran Li,Haiting Lv,Dan Liu,Na Zhao,Qianqian Ding,Xinhua Cao
In this study, a new gelator containing lenalidomide and cholesterol groups was synthesized, which could form stable gels in 1,4-dioxane and mixed solvents of DMF/H2O (v/v, 1/1). The self-assembly process was studied and certified by field emission scanning electron microscopy, UV-vis, IR, XRD, and CA. Based on the results obtained from the abovementioned analyses, the self-assembly structure, aggregation pattern, and surface wettability could be tuned via the addition of melamine due to intermolecular hydrogen bonding between compound 1 and melamine (MA). The irregular lumpy and the closely packed fiber structures could be turned into microbelt and sparse fiber structures after the addition of MA, respectively. Moreover, the hydrophobicity of the xerogel film of 1-MA was obviously increased. The mechanical strength of gel 1-MA was obvisously enhanced due to the addition of MA. The UV-vis, IR, and XRD experiment results showed that the self-assembly process and mode of 1 was changed due to the addition of MA through intermolecular hydrogen bonding between 1 and MA. Therefore, these results provide a method for the regulation of the self-assembly process via intermolecular noncovalent interaction.
研究领域:
化学
·
材料科学
·
生物医学
✓ 已验证
DOI
高影响因子
DRUG DEVELOPMENT AND INDUSTRIAL PHARMACY
·
2015
·
IF 2.101
Zhuojun Gu,Meng Wang,Qiongyan Fang,Huaiyu Zheng,Feiyue Wu,Dai Lin,Ying Xu,Yi Jin
Context: Polyamidoamine (PAMAM) dendrimers have attracted lots of interest as drug carriers. And little study about whether pluronic-attached PAMAM dendrimers could be potential drug delivery systems has been carried on.Objective: Pluronic F127 (PF127) attached PAMAM dendrimers were designed as novel drug carriers.Methods: Two conjugation ratios of PF127-attached PAMAM dendrimers were synthesized. 1H nuclear magnetic resonance (1H-NMR), Fourier transform infrared spectrum (FTIR), element analysis and ninhydrin assay were used to characterize the conjugates. Size, zeta potential and critical micelle concentrations (CMC) were also detected. And DOX was incorporated into the hydrophobic interior of the conjugates. Studies on their drug loading and drug release were carried on. Furthermore, hemolysis and cytotoxicity assay were used to evaluate the toxicity of the conjugates.Results and discussion: PF127 was successfully conjugated to the fifth generation PAMAM dendrimer at two molar ratios of 19% and 57% (PF127 to surface amine per PAMAM dendrimer molecular). The conjugates showed an increased size and a reduced zeta potential. And higher CMC values were obtained than pure PF127. Compared with unconjugated PAMAM dendrimer, PF127 conjugation significantly reduced the hemolytic toxicity and cytotoxicity of PAMAM dendrimer in vitro. The encapsulation results showed that the ability to encapsulate DOX by the conjugate of 19% conjugation ratio was better than that of 57% conjugation ratio. And the maximum is ∼12.87 DOX molecules per conjugate molecule. Moreover, the complexes showed a sustained release behavior compared to pure DOX.Conclusion: Findings from the in vitro study show that the PF127-attached PAMAM dendrimers may be potential carriers for drug delivery.
研究领域:
药学
·
生物医学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
PLANT PHYSIOLOGY AND BIOCHEMISTRY
·
2018
·
IF 2.718
Chen Geng,Tengfei Zhao,Chunxian Yang,Qiaozhuo Zhang,Feng Bai,Junlan Zeng,Fangyuan Zhang,Xiaoqiang Liu,Xiaozhong Lan,Min Chen,Zhihua Liao
N -methylputrescine is the precursor of nicotine and pharmaceutical tropane alkaloids such as hyoscyamine . Putrescine N -methyltransferase (PMT) catalyzes the N -methylation of putrescine to form N -methylputrescine. While the role of PMT in nicotine biosynthesis is clear, knowledge of PMT in the biosynthesis of tropane alkaloids (TAs) and the regulation of polyamines remains limited. We characterized a PMT gene from Hyoscyamus niger , designated HnPMT that was specifically expressed in roots, especially in the secondary roots and dramatically induced by methyl jasmonate (MeJA). The GUS gene was specifically expressed in Arabidopsis roots or in the vascular tissues , including pericycles and endodermis , of the H. niger hairy root cultures , when it was driven by the 5′-flanking promoter region of HnPMT . The recombinant HnPMT was purified for enzymatic assays. HnPMT converted putrescine to form N -methylputrescine, as confirmed by LC-MS. The kinetics analysis revealed that HnPMT had high affinity with putrescine but low catalytic activity, suggesting that it was a rate-limiting enzyme . When HnPMT was suppressed in the H. niger plants by using the VIGS approach, the contents of N -methylputrescine and hyoscyamine were markedly decreased, but the contents of putrescine, spermidine and a mixture of spermine and thermospermine were significantly increased; this suggested that HnPMT was involved in the biosynthesis of tropane alkaloids and played a competent role in regulating the biosynthesis of polyamines . Functional identification of HnPMT facilitated the understanding of TA biosynthesis and thus implied that the HnPMT-catalyzed step might be a target for metabolic engineering of the TA production in H. niger .
研究领域:
植物学
·
代谢工程
·
分子生物学
✓ 已验证
DOI
高影响因子
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
·
2012
·
IF 2.098
Shucai Liang,Hui Yu,Jin Xiang,Wang Yang,Xiaohui Chen,Yanbin Liu,Chen Gao,Guoping Yan
A new naphthalimide modified polyethylenimine (PEI) nanoparticles (called NPEI-NPs) was synthesized and applied as fluorescent probe for rapid, selective and sensitive fluorometric detection of trace DNA. The synthesis involved the covalent modification of PEI with 4-butylamino-N-carboxymethyl-1,8-naphthalimide(BACMN) for getting amphiphilic polymer. Then the amphiphilic polymer was self-assembled in water to give the NPEI-NPs. NPEI-NPs was soluble in water and emitted fluorescence at 545 nm with exciting at 460 nm. The fluorescence spectra resulting from the interaction between NPEI-NPs and DNA indicated that the fluorescence of NPEI-NPs increased in the present of DNA. Therefore, a fluorescence enhancement method was developed for the determination of trace fish sperm DNA (fsDNA) and calf thymus DNA (ctDNA). Under the optimal conditions, the calibration curves were linear over the concentration ranges of 0.05–2.8 μg/mL for fsDNA and 0.08–3.0 μg/mL for ctDNA. The detection limits for fsDNA and ctDNA were 1.6 and 2.0 ng/mL, respectively. The proposed method has been employed to quantify DNA in synthetic samples with the satisfactory results.
研究领域:
生物化学
·
分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Materials Today Physics
·
2021
·
IF 9.298
Feichong Yao,Wenhao Xie,Ming Yang,Hang Zhang,Hongbo Gu,Ai Du,Nithesh Naik,David P. Young,Jing Lin,Zhanhu Guo
With the purpose of ameliorating the electrical property, permittivity and magnetoresistance of polyaniline (PANI) nanofibers , three types of phenylenediamine (PDA), including o -PDA, m -PDA, and p -PDA, and different contents of PDA have been incorporated into the PANI polymer backbone by the interfacial copolymerization of aniline with PDA. The results demonstrate that different types and contents of PDAs could disclose the distinct effects on the chemical structures , crystalline structures, and morphologies for copolymers of aniline with PDA affirmed by Fourier transform infrared (FTIR) spectroscopy, solid-state 13 C nuclear magnetic resonance ( 13 C NMR), X-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscopy (TEM). The molecular weight of all copolymers is reduced by several orders of magnitude relative to pure PANI nanofibers confirmed by gel permeation chromatography (GPC). The resistivity variations for the copolymers of aniline with different types of PDAs are well explained from the point view of their molecular structures based on the first-principle simulations (i.e. intrachain electrical conductivity) and degree of crystallinity gained from XRD (i.e. interchain electrical conductivity). A tunable room-temperature magnetoresistance (MR) and a controllable negative permittivity are discovered in the copolymers of aniline with different types and contents of PDAs. This work provides a new insight for the manipulation of electrical transport for PANI nanofibers and helps seek the new applications of conductive polymer .
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
Molecular Catalysis
·
2021
·
IF 5.062
Chang Bai,Yong Liu,Cong Wang,Xiao-Cong Zhang,Jia-Xuan Wu,Hai-Tao Ren,Xu Han
Although the oxidation processes mediated by persulfate (PS) and peroxymonosulfate (PMS) attract more attention in the degradation of various recalcitrant contaminants, the high concentrations of oxidants required for the low concentrations of contaminants always limit their large-scale applications. In this work, aniline can be effectively oxidized by CuO and PS under pH-neutral and alkaline conditions. The increased observed rate constant ( k obs ) values with increasing pHs indicate that the oxidation of aniline is facilitated by solution OH − . Meanwhile, the low ratios between the removed PS and aniline (1.19 at pH 7.0 and 1.68 at pH 12.0) indicate the high catalytic oxidation efficacy of the CuO-PS system. The insignificant contributions of SO 4 − , OH, 1 O 2 and O 2 − to aniline oxidation in quenching experiments and EPR analysis suggest that PS is likely activated on the surface of CuO via the non-radical pathway. The presence of carbon-centered radicals (CCRs), as well as UV and GC MS analysis, indicates the important intermediates of PhNH 2 + and PhNH radicals during the oxidation process, revealing that separate transfer of an electron from aniline to the activated PS, followed by subsequent abstraction of a H + by OH − to form PhNH are two important steps in the oxidation process. Further coupling of PhNH radicals results in the formation of insoluble polyaniline polymers at pHs 7.0 and 12.0. The high thermal stability and ideal pseudo-capacitive properties of the insoluble products indicate that the polyaniline produced from aniline wastewater can be used for high-temperature-resistant materials or capacitors. This study provides an efficient alternative to turn aniline waste to polyaniline polymers.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
CARBOHYDRATE POLYMERS
·
2018
·
IF 5.158
Shaojie Liu,Huazhe Liang,Tingting Sun,Desheng Yang,Meng Cao
Polyamidoamine (PAMAM) dendrimers of G1.0 and 2.0 were synthesized by the repeated Michael addition and ester aminolysis of ethylenediamine and methyl acrylate. Through the reductive amination reaction of primary amines in PAMAM and carbonyl groups in 4-oxo-2,2,6,6-tetramethylpiperidine-1-oxyl (4-oxo-TEMPO), the water-soluble PAMAM immobilized TEMPO (PAMAM-TEMPO) was successfully prepared. The obtained PAMAM-TEMPO was characterized by Fourier transform infrared spectroscopy (FT-IR) and ultraviolet-visible spectrophotometer (UV–vis). PAMAM-TEMPO was used as catalyst instead of free TEMPO for selective catalytic oxidation of primary hydroxyl groups in cellulose with water as reaction medium. The results showed that the catalytic performance of G1.0 PAMAM-TEMPO with 28.8% TEMPO loading was equivalent to free TEMPO. After salting out the supernatant of oxidation mixture, PAMAM-TEMPO was recovered by extraction with N ,N- dimethylformamide and reused for further oxidation cycles. No significant reduction in catalytic performance was found after 4 oxidation cycles. The recovery of PAMAM-TEMPO after each cycle was about 90%. By sonication of oxidized cellulose obtained with G1.0 PAMAM-TEMPO as catalyst, the individualized cellulose nanofibers with approximately 10 nm in diameter were successfully prepared. This is the first report on the use of immobilized TEMPO catalysts comparable to the performance of free TEMPO to oxidize cellulose in water.
研究领域:
化学工程
·
材料科学
·
绿色化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
POLYMER COMPOSITES
·
2013
·Vol. 35
·期 4
·627-635
·
IF 1.482
Lei Xia,Baoqing Shentu,Zhixue Weng
The effect of dendrimer-like polyamidoamine grafted attapulgite (ATP-PAMAM) on the microstructure and morphology of Nylon-6 (PA6) was investigated. The ATP-PAMAM nanoparticles were prepared by treating attapulgite (ATP) with heat and acid followed by grafting with polyamidoamine (PAMAM) molecules, which was confirmed by Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), and dispersion state in formic acid. The X-ray diffraction (XRD) analysis result indicated that the grafting modification was occurred on the surface of fibrous crystals and did not shift the crystal structure of ATP. PA6/ATP-PAMAM (G 2.0 ) nanocomposites with different modified ATP content were prepared by melt compounding in a twin screw extruder. XRD measurements suggested that the intensity of diffraction peak of α crystalline form of PA6 decreased gradually as the inclusion of ATP-PAMAM(G 2.0 ) into the PA6 matrix, while that of γ crystalline form increased gradually. The results of molau experiment and scanning electron microscopy (SEM) observation showed not only a uniform dispersion of ATP-PAMAM(G 2.0 ) in the PA6 matrix but also a strong interfacial adhesion between them. Mechanical investigation (by tensile test) showed an obvious improvement in the presence of surface modified ATP. POLYM. COMPOS., 35:627–635, 2014. © 2013 Society of Plastics Engineers
研究领域:
材料科学
·
高分子化学
✓ 已验证
产品关联
DOI
高影响因子
MATERIALS LETTERS
·
2022
·
IF 3.574
Zhiye Qiu,Bin Wu,Huali Miao,Yang Yang,Zili Wang,Minghua Wu,Jiping Wang,Jindan Wu
Herein, a rapid and efficient deposition of polydopamine (PDA) was achieved by using a solvent-assisted method. Decamethyl cyclopentasiloxane (D5) was selected as the solvent, in which the hydrophilic dopamine suspended and approached the fabric rapidly due to its natural affinity with the hydration layer of the cotton fibers . The fast formation of PDA coatings was realized with high utilization of dopamine and improved uniformity. It was found that the type and amount of liquid presoaked by the fabric were critical for the PDA deposition process. This novel method is applicable for the deposition and reaction of various hydrophilic finishing agents on hydrophilic fabrics.
研究领域:
材料科学
·
纺织工程
✓ 已验证
产品关联
DOI
高影响因子
SURFACE & COATINGS TECHNOLOGY
·
2023
·
IF 5.4
Liping Yan,Siming Yan,Yi He,Yi Fan,Xinyu Cheng,Huilian Zhou,Jiamin Zhong,Zhiyuan Li,Jinxue Song,Hongjie Li
In this study, propylamine and ethylenediamine intercalated α-ZrP nanocomposites (denoted by P-α-ZrP and E-α-ZrP, respectively) were synthesized. The effects of propylamine and ethylenediamine intercalated α-ZrP nanocomposites and their reinforcements on the corrosion resistance and mechanical properties of Ni-B coatings were investigated and compared. The morphology and structure of the three composites were characterized using transmission electron microscopy, atomic force microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, infrared spectroscopy, thermogravimetric analysis, and particle size analysis. Both propylamine and ethylenediamine intercalation increase the layer spacing of α-ZrP, but do not change the lamellar structure of α-ZrP. The EIS test results show that both Ni-B/P-α-ZrP and Ni-B/E-α-ZrP composite coatings have significantly lower corrosion rates than Ni-B and Ni-B/α-ZrP composite coatings. Compared to Ni-B/α-ZrP, the corrosion rates are reduced by 32 % and 76 % respectively. The R ct values for Ni-B/P-α-ZrP and Ni-B/E-α-ZrP composite coatings are also distinctly higher than Ni-B/α-ZrP, with Ni-B/E-α-ZrP having the highest values. In addition, Ni-B/P-α-ZrP and Ni-B/E-α-ZrP composite coatings are both harder than Ni-B/α-ZrP and have lower average coefficients of friction and wear rates than Ni-B/α-aZrP. Among them, the Ni-B/E-α-ZrP composite coating has the highest microhardness (1163.64 ± 21.20 HV) and the best wear resistance. The wear rate is reduced by 87 % and 65 % compared to Ni-B and Ni-B/α-ZrP composite coatings respectively. In conclusion, both P-α-ZrP and E-α-ZrP are better than α-ZrP in terms of enhancement, with E-α-ZrP being the best.
研究领域:
材料科学
·
电化学
·
表面工程
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）