Frontiers in Nutrition
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2022
·
IF 6.59
Luo Bi,Lv Jia,Li Kejie,Liao Peiran,Chen Peng
This study aimed to extract polysaccharides from Citrus medica L. var. sarcodactylis (finger citron fruits) and analyze their structures and potential bioactivities. A new polysaccharide named K-CMLP was isolated and purified by Diethylaminoethylcellulose (DEAE)-Sepharose Fast Flow and DEAE-52 cellulose column chromatography with an average molecular weight of 3.76 × 103 kDa. Monosaccharide composition analysis revealed that K-CLMP consisted of rhamnose, galactose, and glucose, with a molar ratio of 6.75:5.87:1.00. Co-resolved by methylation and two-dimensional nuclear magnetic resonance (NMR), K-CLMP was alternately connected with 1, 2-Rha and 1, 4-Gal to form the backbone, and a small number of glucose residues was connected to O-4 of rhamnose. The results of DPPH⋅ and ABTS+⋅ radical scavenging assays indicated that both crude polysaccharide Citrus medica L. var. polysaccharide (CMLP) and K-CLMP exhibited strong free-radical-scavenging properties in a dose-dependent manner. In addition, K-CMLP significantly inhibited the production of pro-inflammatory cytokines (IL-6 and TNF-α) and reactive oxygen species (ROS) in RAW 264.7 cells treated with LPS. These results provide a basis for further use as one of the potential functions of food or natural medicine.
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Biomass Conversion and Biorefinery
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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.
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LANGMUIR
·
2022
·
IF 4.331
Hongjiao Wu,Jun Liu,Zhuoyu Chen,Pengcheng Lin,Wentao Ou,Zian Wang,Wei Xiao,Ying Chen,Donglin Cao
Peroxidase-like nanozymes with robust catalytic capacity and detection specificity have been proposed as substitutes to natural peroxidases in biochemical sensing. However, the catalytic activity enhancement, detection mechanism, and application of nanozyme-based biosensors toward l-cysteine (l-Cys) detection still remain significant challenges. In this work, a doped ferrite nanozyme with well-defined structure and surface charges is fabricated by a two-step method of continuous flow coprecipitation and high-temperature annealing. The resulted ferrite nanozyme possesses an average size of 54.5 nm and a zeta-potential of 6.45 mV. A high-performance biosensor is manufactured based on the peroxidase-like catalytic feature of the doped ferrite. The ferrite nanozyme can oxidize the 3,3′,5,5′-tetramethylbenzidine (TMB) with the assistance of H2O2 because of the instinctive capacity to decompose H2O2 into ·OH. The Michaelis–Menten constants (0.0911 mM for TMB, 0.140 mM for H2O2) of the ferrite nanozyme are significantly smaller than those of horseradish peroxidase. A reliable colorimetric method is established to selectively analyze l-Cys via a facile mixing-and-detecting methodology. The detection limit and linear range are 0.119 μM and 0.2–20 μM, respectively. Taking the merits of the ferrite nanozyme-based biosensors, the l-Cys level in the human serum can be qualitatively detected. It can be anticipated that the surface-charged ferrite nanozyme shows great application prospects in the fields of bioanalytical chemistry and point-of-care testing.
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POLYMER TESTING
·
2022
·
IF 4.931
Zhenghui Lei,Ke Jiang,Yuzhu Chen,Jinqiu Qi,Jiulong Xie,Xingyan Huang,Yongze Jiang,Shaobo Zhang,Shanshan Jia,Hui Xiao
Although soy protein (SP) adhesives have shown great potential in promoting the green and sustainable development of the wood industry, the practical application of SP adhesives is limited by poor performance (bonging strength, mold resistance and water resistance). Cross-linking modification is considered to be the most effective modification method for SP adhesives. In this work, non-antibacterial l -tyrosine (TYR) was treated with epichlorohydrin to graft multiple epoxy groups and transformed into tetraepoxy l -tyrosine (ETY). Interestingly, ETY exhibited obvious antifungal properties with a bacteriostatic rate as high as 98.3%. Adding a low amount (3 wt%) of ETY, the wet shear strength of the modified adhesive was 169.1% higher than that of the pristine SP adhesive, reaching 1.83 MPa. Moreover, in an environment of 28 °C and 80% humidity, both uncured and cured SP adhesives (with 3 wt% ETY) exhibited an anti-mold period of more than 30 days. Therefore, this work reveals that non-antibacterial bio-based materials may be endowed with antibacterial properties through epoxidation and transformed into multifunctional modifiers, and provides a new way for the development of high-strength antibacterial bio-based adhesives.
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Food Chemistry-X
·
2022
·
IF 6.443
Sen Li,Mengyao Li,Hongwei Cao,Xiao Guan,Ying Zhang,Kai Huang,Yu Zhang
To improve the quality of wheat gluten (WG) gels, the effect of l -Lysine on gelatin formation of WG under microwave (MW) irradiation was studied. The strength of WG gels treated by MW heating increased significantly (P < 0.05) in the alternating electromagnetic fields with zwitterionic l -Lysine. l -Lysine enhanced the surface hydrophobicity of WG under MW irradiation indicating that the dielectric buffering of l -Lysine changed the conformation of WG. The second structure of WG by Fourier transformed infrared spectroscopy showed that the α-helix content of WG decreased, while the β-sheet content. Furthermore, compared to the non- l -Lysine addition group, the ultraviolet absorption and fluorescence intensity of the WG increased. Scanning electron microscopy presented denser porous network microstructure of WG gels by MW treatment with adding l -Lysine. These results elucidate the regulation effect of l -Lysine on WG gelation in the MW field.
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APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY
·
2022
·Vol. 194
·期 8
·3453-3467
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IF 3.094
Ye Hangyu,Li Xiaojun,Li Luyuan,Zhang Yinjun,Zheng Jianyong
Aspergillus niger has been used for homologous and heterologous expressions of many protein products. In this study, the α-L-rhamnosidase from A. niger (Rha-N1, GenBank XP_001389086.1) was homologously expressed in A. niger 3.350 by Agrobacterium tumefaciens -mediated transformation. The enzyme activity of Rha-N1 was 0.658 U/mL, which was obtained by cultivation of engineered A. niger in a 5-L bioreactor. Rha-N1 was purified by affinity chromatography and characterized. The optimum temperature and optimum pH for Rha-N1 were 60 °C and 4.5, respectively. Enzyme activity was promoted by Al 3+ , Li + , Mg 2+ , and Ba 2+ and was inhibited by Mn 2+ , Fe 3+ , Ca 2+ , Cu 2+ , and organic solvents. The result indicated that rutin was the most suitable substrate for Rha-N1 by comparison with the other two flavonoid substrates hesperidin and naringin. The transformed products of isoquercitrin, hesperetin-7-O-glucoside, and prunin were identified by LC–MS and 1 H-NMR.
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ANALYTICA CHIMICA ACTA
·
2022
·
IF 6.911
Sisi Tang,Xiaodan Wu,Pengfei Zhao,Kangling Tang,Yu Chen,Jinli Fu,Shu Zhou,Zhaoxia Yang,Zhaohui Zhang
This work firstly developed a near-infrared fluorescence capillary imprinted sensor with high selectivity and sensitivity for the chiral recognition of l -histidine. The near-infrared fluorescence imprinted polymer prepared by sol-gel method using CdTe quantum dots as the near-infrared fluorescence source was self-sucked into activated capillary to form the fluorescence imprinted capillary. The fluorescence imprinted capillary sensor had higher fluorescence response efficiency. With the superior stability, reproducibility and reusability, the fluorescence capillary imprinted sensor displayed higher selectivity toward l -histidine. Under the optimal conditions, the fluorescence intensity (λex = 370 nm, λem = 695 nm) of the fluorescence capillary imprinted sensor was enhanced in proportion to l -histidine concentration ranged from 0.1 pM to 1.8 pM with a limit of detection of 0.08 pM. Spiking experiment showed that the fluorescence capillary imprinted sensor was successfully used for determination of l -histidine in human urine and serum with the recoveries of 99.6–102.7%. The near-infrared fluorescence capillary imprinted sensor possessed significantly potential for high sensitive detection of l -histidine, which realized trace-level analysis for micro-volume sample and provided promising utility for green chemical.
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Foods
·
2022
·Vol. 11
·期 9
·1252
·
IF 5.561
Ri-Si Wang,Pan-Hao Dong,Xi-Xiang Shuai,Ming-Shun Chen
This study evaluated thirteen different black mulberry fruits (Morus nigraL.) grown in the Guangdong region in order to select the best cultivar for health benefits and commercial applications. The phenolic compounds were identified and quantified using UPLC-ESI-MS/MS. The antioxidant activity was evaluated by three in vitro methods. Significant differences among samples were found regarding total soluble solids (6.20–15.83 °Brix), titratable acidity (5.82–48.49 mg CA/g), total phenolic contents (10.82–27.29 mg GAE/g), total flavonoid contents (1.21–2.86 mg RE/g) and total anthocyanin contents (2.91–11.86 mg CE/g). Fifty-five different phenolic compounds were identified, of which fifteen were reported in mulberry for the first time, but only forty-six of them were quantitated. The DPPH radical scavenging activity, ABTS radical scavenging activity and ferric ion-reducing antioxidant power varied significantly among the samples. Overall, cultivars with better combinations of phenolic compounds and antioxidant activity were Qiong46 (M-2), Yuebanguo (M-4) and Heizhenzhu (M-10), which were recommended for commercial cultivation.Keywords:mulberry fruit;cultivar;phenolic compounds;antioxidant activity
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LUMINESCENCE
·
2022
·Vol. 37
·期 8
·1267-1274
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IF 2.613
Qi Wang,Bin Zhu,Yejiao Han,Xin Yang,Yanan Xu,Ying Cheng,Taotao Liu,Jiana Wu,Shengling Li,Lifeng Ding,Jingjing Bai,Yulan Niu
In this work, carbon dots (CDs) was easily synthesized from aspartic acid through a pyrolysis method. Based on their favourable fluorescence properties, CDs were utilized to design a metal ion-mediated fluorescent probe for N -acetyl- l -cysteine (NAC) detection. The fluorescence intensity of CDs was firstly quenched by manganese ions (Mn 2+ ) through static quenching effect and subsequently restored by NAC via the combination with Mn 2+ due to the coordination effect. Therefore, the fluorescent turn-on sensing of NAC was actuated based on the fluorescence quenching stimulated by Mn 2+ and recovery induced by coordination. The fluorescence recovery efficiencies showed a proportional range to the concentration of NAC in the range 0.04–5 mmol L −1 and the detection limit was 0.03 mmol L −1 . Furthermore, this metal ion-mediated fluorescent nanoprobe was applied to human urine sample detection and the standard recovery rates were located in the range 97.62–102.34%. This was the first time that Mn 2+ was used to construct a fluorescent nanoprobe for NAC. Compared with other heavy metal ions, Mn 2+ with good biosecurity prevented the risk of application, which made the nanoprobe green and biopractical. The facile synthesis of CDs and novel metal ion-mediated sensing mode made it a promising method for pharmaceutical analysis.
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MOLECULES
·
2022
·Vol. 27
·期 9
·2865
·
IF 4.927
Xiuqiong Huang,Wei Gao,Xuan Yun,Zhixing Qing,Jianguo Zeng
In recent years, synthetic antioxidants that are widely used in foods have been shown to cause detrimental health effects, and there has been growing interest in antioxidants realised from natural plant extracts. In this study, we investigate the potential effects of natural antioxidant components extracted from the forage plant marigold on the oxidative stability of soybean oil. First, HPLC-Q-TOF-MS/MS was used with 1,1-diphenyl-2-picrylhydrazyl (DPPH) to screen and identify potential antioxidant components in marigold. Four main antioxidant components were identified, including quercetagetin-7-O-glucoside (1), quercetagetin (2), quercetin (3) and patuletin (4). Among them, quercetagetin (QG) exhibited the highest content and the strongest DPPH radical scavenging activity and effectively inhibited the production of oxidation products in soybean oil during accelerated oxidation, as indicated by reductions in the peroxide value (PV) and acid value (AV). Then, the fatty acids and volatile compounds of soybean oil were determined with gas chromatography–mass spectrometry (GC-MS) and headspace solid-phase microextraction–gas chromatography–mass spectrometry (HS-SPME-GC-MS). A total of 108 volatile components, including 16 alcohols, 23 aldehydes, 25 ketones, 4 acids, 15 esters, 18 hydrocarbons, and 7 other compounds, were identified. QG significantly reduced the content and number of aldehydes and ketones, whereas the formation of acids and hydrocarbons was completely prevented. In addition, the fatty acid analysis demonstrated that QG significantly inhibited oxidation of unsaturated fatty acids. Consequently, QG was identified as a potential, new natural antioxidant that is believed to be safe, effective and economical, and it may have potential for use in plant extracts feed additives.Keywords:Tagetes erectaL.;quercetagetin;DPPH-HPLC-Q-TOF/MS;HS-SPME-GC-MS;oxidative stability
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Microbial Biotechnology
·
2022
·Vol. 15
·期 5
·1610-1621
·
IF 6.575
Xing Liu,Xiao Han,Yuan Peng,Chunlin Tan,Jing Wang,Hongsong Xue,Ping Xu,Fei Tao
Summary 3, 4-Dihydroxyphenyl- l -alanine ( l -DOPA) is a compound of high medical value and is considered effective as a treatment for Parkinson’s disease. Currently, bioproduction of l -DOPA is mainly carried out by whole-cell catalysis mediated by recombinant Escherichia coli carrying heterogeneous tyrosine phenol lyase. Vibrio natriegens is increasingly attracting attention owing to its superiority, including extremely rapid growth and high soluble protein expression capacity. In this study, we attempt to develop an efficient whole-cell catalyst for l -DOPA production using V. natriegens as the chassis. The maximum soluble protein expression by V. natriegens was accomplished in 4 h at 37°C, which was equivalent to that achieved by E. coli in 16 h at 16°C. Furthermore, the maximum productivity reached over 10.0 g l −1 h −1 in the early stage of biocatalysis, nearly two-fold higher than previously reported. Approximately 54.0 g l −1 l -DOPA was obtained with a catechol conversion rate greater than 95%. In conclusion, V. natriegens displays advantages, including rapid protein expression and catalytic rate in the catalysis process for l -DOPA production. These findings strongly suggest that V. natriegens has remarkable potential as a whole-cell catalysis chassis for the production of valuable chemicals.
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RSC Advances
·
2022
·Vol. 12
·期 5
·2947-2958
·
IF 4.036
Jing Wang,Chengbao Liu,Bei Qian
A novel L-histidine based ionic liquid (LHIL) was developed and successfully synthesized. Its structure was confirmed by Fourier-transform infrared spectroscopy, UV-vis spectroscopy, X-ray photoelectron spectroscopy, 1H-NMR and high-resolution mass spectrometry. The outstanding corrosion inhibition effect of the LHIL on mild steel in 1 M hydrochloric acid was thoroughly evaluated by Tafel plots, electrochemical impedance spectroscopy, and localized electrochemical strategies. The results revealed that the corrosion of mild steel was effectively suppressed by the adsorption of LHIL on its surface, and the best inhibition efficiency reached 98.8%. The adsorption behavior of LHIL on steel obeyed the Langmuir adsorption isotherm, which involved both chemisorption and physisorption. Theoretical calculations indicated the strong chemisorption of LHIL on steel, as proved by the low energy gap (ΔE = 0.0522 eV) and high binding energy (Ebinding = 303.47 kcal mol−1), which clearly confirmed the effectiveness of LHIL for steel protection.
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