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  • 1
    Online Resource
    Online Resource
    The Antioxidant and Antibacterial Activities of the Pyridine‐4‐Aldehyde Schiff Bases Grafted Chloracetyl Chitosan Oligosaccharide Derivatives
    Wiley ; 2023
    In:  Starch - Stärke Vol. 75, No. 1-2 ( 2023-01)
    Details
    In: Starch - Stärke, Wiley, Vol. 75, No. 1-2 ( 2023-01)
    Abstract: As a reactive intermediate, chloracetyl chitosan oligosaccharide (CACS) can be nucleophilic substituted by some bioactive groups to give novel derivatives of chitosan oligosaccharide (COS). The Schiff bases of pyridine‐4‐aldehyde are grafted onto CACS to give four COS derivatives in this paper. Specific structural characterization is implemented by fourier‐transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR). The degree of substitution (DS) of COS derivatives is quantitatively calculated by ratio of hydrogen proton integral. Their antioxidant property is evaluated using free radical scavenging assay towards 1,1‐diphenyl‐2‐picrylhydrazyl (DPPH) and superoxide anion radicals, and the antibacterial activity against Staphylococcus aureus ( S. aureus ) and Escherichia coli ( E. coli ) is also investigated. The results revealed that the pyridine‐4‐aldehyde Schiff bases grafted chloracetyl chitosan oligosaccharide derivatives showed better antioxidant activity as well as antibacterial activity than COS and CACS, which may be related to the positive charge of these derivatives. Among all final products, derivative BPCACS with the highest DS has the best bioactivity with scavenging rate of 91.49% for the DPPH assay and inhibition diameter of 39.25 mm for S. aureus inhibitory assay, respectively. These results indicated that COS derivatives with enhanced biological activities could serve as potential biomaterial for antioxidant and antibacterial applications.
    Type of Medium: Online Resource
    ISSN: 0038-9056 , 1521-379X
    URL: Issue
    URL: Article
    DOI: 10.1002/star.v75.1-2
    DOI: 10.1002/star.202100268
    Language: English
    Publisher: Wiley
    Publication Date: 2023
    detail.hit.zdb_id: 1481133-9
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  • 2
    Online Resource
    Online Resource
    Synthesis of aminopyridinium‐grafted starch derivatives and evaluation of their antioxidant property
    Wiley ; 2017
    In:  Starch - Stärke Vol. 69, No. 7-8 ( 2017-07)
    Details
    In: Starch - Stärke, Wiley, Vol. 69, No. 7-8 ( 2017-07)
    Abstract: In order to improve the bioactivity of starch, novel starch derivatives were developed including 2‐(2‐aminopyridinium)acetyl starch (2APASC), 2‐(3‐aminopyridinium)acetyl starch (3APASC), 2‐(4‐aminopyridinium)acetyl starch (4APASC), 2‐(2,3‐diaminopyridinium)acetyl starch (2,3DAPASC), 2‐(2,6‐diaminopyridinium)acetyl starch (2,6DAPASC), and 2‐(3,4‐diaminopyridinium)acetyl starch (3,4DAPASC). The in vitro antioxidant capacities against hydroxyl‐radical, DPPH‐radical, and superoxide‐radical for all synthesized starch derivatives were evaluated using free radicals scavenging assays. The results showed that the scavenging effect of starch derivatives bearing aminopyridinium groups was better than starch. Especially, 2,3DAPASC and 2,6DAPASC could scavenge hydroxyl‐radicals completely at 0.4 mg/mL. Moreover, the antioxidant property of synthesized starch derivatives was affected by the different positions and the number of amino groups on pyridinium rings. Because the aminopyridinium acetyl starch derivatives could be synthesized conveniently and also possessed significantly strong antioxidant activity, this synthetic strategy might provide an effective tool to broaden further utilization of starch.
    Type of Medium: Online Resource
    ISSN: 0038-9056 , 1521-379X
    URL: Issue
    URL: Article
    DOI: 10.1002/star.v69.7-8
    DOI: 10.1002/star.201600259
    Language: English
    Publisher: Wiley
    Publication Date: 2017
    detail.hit.zdb_id: 1481133-9
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  • 3
    Online Resource
    Online Resource
    Synthesis, Characterization, and the Antifungal Property of Aminoethyl Chitosan Quaternary Ammonium Salts
    Wiley ; 2018
    In:  Starch - Stärke Vol. 70, No. 5-6 ( 2018-05)
    Details
    In: Starch - Stärke, Wiley, Vol. 70, No. 5-6 ( 2018-05)
    Abstract: Chemical modification of chitosan is one of effective methods to improve the biological activity of chitosan. In this paper, aminoethyl chitosan quaternary ammonium salts, including N ‐trimetyl quaternary ammonium salt chitosan (TMC), 6‐O‐(aminoethyl)‐2‐trimethyl quaternary ammonium chitosan derivative (ONC), and 6‐ N ‐(aminoethyl)‐2‐trimethyl quaternary ammonium chitosan derivative (NNC), are successfully designed, synthesized, and characterized by FT‐IR, 1 H NMR, and elemental analyses. Moreover, three kinds of antifungal activities, including B. cinerea Pers ., Gibberella zea , and P. asparagi , are all tested by hyphal measurement in vitro. The results show that all chitosan derivatives have better antifungal activities than chitosan. And the antifungal activity decrease in the order: NNC 〉 ONC  〉 TMC 〉 chitosan at 1.0 mg mL −1 . Furthermore, the inhibitory indices of NNC and ONC against three kinds of phytopathogens are higher than 75% at 1.0 mg mL −1 . Especially, the inhibitory index of NNC against B. cinerea Pers . attain even 90% at 1.0 mg mL −1 . These data demonstrate that the aminated chitoan derivative could remarkably improve the antifungal activity of chitosan. On the one hand, the higher positive charge would interact with the anionic components to damage the cell wall. On the other hand, based on the “permeability” point, the aminoethyl as lipophilic group might pass the oil film into the cell.
    Type of Medium: Online Resource
    ISSN: 0038-9056 , 1521-379X
    URL: Issue
    URL: Article
    DOI: 10.1002/star.v70.5-6
    DOI: 10.1002/star.201700266
    Language: English
    Publisher: Wiley
    Publication Date: 2018
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  • 4
    Online Resource
    Online Resource
    Synthesis and Characterization of Inulin Derivatives Bearing Urea Groups with Promising Antifungal Activity
    Wiley ; 2019
    In:  Starch - Stärke Vol. 71, No. 1-2 ( 2019-01)
    Details
    In: Starch - Stärke, Wiley, Vol. 71, No. 1-2 ( 2019-01)
    Abstract: The toxicity concerns associated with chemical fungicides currently on the market have resulted in an increased demand for alternative ecofriendly fungicides. As a biodegradable and biocompatible dietary fiber, inulin shows potential as such a compound, given its lack of toxicity. In the current study, seven novel inulin derivatives with promising antifungal activity (BUCAIL, 2CBUCAIL, 3CBUCAIL, 4CBUCAIL, 3,4CBUCAIL, 2FBUCAIL, and 2BBUCAIL) are synthesized via condensation reactions of chloroacetyl inulin (CAIL) with urea groups bearing 4‐amino‐pyridine. Their structures are confirmed using FT‐IR, 1 H NMR, 13 C NMR, and elemental analysis. Their antifungal activity against three kinds of phytopathogen ( Fusarium oxysporum f. sp. niveum, Phomopsis asparagus , and Fusarium oxysporum f. sp. cucumebrium Owen) is evaluated using the mycelial growth rate in vitro at concentrations of 0.10, 0.25, 0.50, 0.75, and 1.0 mg mL −1 . Results reveal that all seven inulin derivatives show improved antifungal properties compared with unmodified inulin, and two obvious inhibition rules are found: 3,4CBUCAIL  〉  4CBUCAIL  〉  3CBUCAIL  〉  2CBUCAIL  〉  BUCAIL  〉  CAIL  〉  inulin and 2FBUCAIL  〉  2CBUCAIL  〉  2BBUCAIL  〉  BUCAIL  〉  CAIL  〉  inulin. Thus, the introduction of urea groups into inulin derivatives could be key to increasing the antifungal activity of such compounds.
    Type of Medium: Online Resource
    ISSN: 0038-9056 , 1521-379X
    URL: Issue
    URL: Article
    DOI: 10.1002/star.v71.1-2
    DOI: 10.1002/star.201800058
    Language: English
    Publisher: Wiley
    Publication Date: 2019
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  • 5
    Online Resource
    Online Resource
    Preparation and Characterization of Chitosan Derivatives Bearing Imidazole Ring with Antioxidant, Antibacterial, and Antifungal Activities
    Wiley ; 2023
    In:  Starch - Stärke Vol. 75, No. 3-4 ( 2023-03)
    Details
    In: Starch - Stärke, Wiley, Vol. 75, No. 3-4 ( 2023-03)
    Abstract: In this study, three series of chitosan derivatives bearing imidazole rings, including the Schiff‐bases of chitosan, N ‐substituted chitosan, and quaternized chitosan are designed and synthesized. The structures of these chitosan derivatives are verified by FT‐IR and 1 H NMR, and their antioxidant, antibacterial, and antifungal activities are tested. The Schiff‐bases of chitosan and N ‐substituted chitosan have similar biological properties compared with chitosan. Derivatives 2IMTMC, 4IMTMC, MIMTMC, and BIMTMC exhibit significant antioxidant ability and antifungal activity, especially derivative BIMTMC. All the quaternized chitosan remarkably inhibits Escherichia coli , Staphylococcus aureus , and Vibrio harvey , especially derivative BIMTMC, whose minimum inhibitory concentration values are 0.03125, 0.0625, and 0.03125 mg mL −1 , respectively. The results indicated that quaternized chitosan are synergistic with imidazole groups and have the better antioxidant, antifungal, and antibacterial properties than chitosan, which can be used as drug materials for antioxididant and antimicrobial purposes.
    Type of Medium: Online Resource
    ISSN: 0038-9056 , 1521-379X
    URL: Issue
    URL: Article
    DOI: 10.1002/star.v75.3-4
    DOI: 10.1002/star.202200204
    Language: English
    Publisher: Wiley
    Publication Date: 2023
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  • 6
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    Online Resource
    Combined effects of paper‐containing 1‐methylcyclopropene with nitrogen‐modified atmosphere packaging in the logistics process of e‐commerce on fruit quality of plum ( Prunus salicina cv. ‘Qingcuili’) during shelf life
    Wiley ; 2023
    In:  International Journal of Food Science & Technology Vol. 58, No. 8 ( 2023-08), p. 4144-4154
    Details
    In: International Journal of Food Science & Technology, Wiley, Vol. 58, No. 8 ( 2023-08), p. 4144-4154
    Abstract: In this study, the paper‐containing 1‐methylcyclopropene (1‐MCP) and 100% nitrogen (modified atmosphere packaging, MAP) were used to treat plums during logistics process of e‐commerce (about 24 h). Quality changes of plums were analysed during shelf life at 25 °C and 4 °C for 6 and 12 days, respectively. Results showed that compared with control, 1‐MCP, MAP and 1‐MCP + MAP decreased respiration rate and ethylene production, maintained lower weight loss, higher green ( a *) and firmness, maintained titratable acidity (TA) and ascorbic acid (ASA) content, reduced malondialdehyde (MDA) accumulation, inhibited polyphenol oxidase (PPO) activity and maintained peroxidase (POD) activity. The quality of 1‐MCP + MAP group was the best, followed by the 1‐MCP group and MAP group. Overall, the combination of 1‐MCP with MAP treatments in the logistics process of e‐commerce has potential prospects for application to maintain the shelf life quality of fruits.
    Type of Medium: Online Resource
    ISSN: 0950-5423 , 1365-2621
    URL: Issue
    URL: Article
    DOI: 10.1111/ijfs.v58.8
    DOI: 10.1111/ijfs.16486
    Language: English
    Publisher: Wiley
    Publication Date: 2023
    detail.hit.zdb_id: 2016518-3
    detail.hit.zdb_id: 2401430-8
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  • 7
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    Online Resource
    Asymmetric Total Synthesis of Sarpagine and Koumine Alkaloids
    Wiley ; 2021
    In:  Angewandte Chemie International Edition Vol. 60, No. 23 ( 2021-06), p. 13105-13111
    Details
    In: Angewandte Chemie International Edition, Wiley, Vol. 60, No. 23 ( 2021-06), p. 13105-13111
    Abstract: We report here a concise, collective, and asymmetric total synthesis of sarpagine alkaloids and biogenetically related koumine alkaloids, which structurally feature a rigid cage scaffold, with L ‐tryptophan as the starting material. Two key bridged skeleton‐forming reactions, namely tandem sequential oxidative cyclopropanol ring‐opening cyclization and ketone α‐allenylation, ensure concurrent assembly of the caged sarpagine scaffold and installation of requisite derivative handles. With a common caged intermediate as the branch point, by taking advantage of ketone and allene groups therein, total synthesis of five sarpagine alkaloids (affinisine, normacusine B, trinervine, N a ‐methyl‐16‐epipericyclivine, and vellosimine) with various substituents and three koumine alkaloids (koumine, koumimine, and N ‐demethylkoumine) with more complex cage scaffolds has been accomplished.
    Type of Medium: Online Resource
    ISSN: 1433-7851 , 1521-3773
    URL: Issue
    URL: Article
    DOI: 10.1002/anie.v60.23
    DOI: 10.1002/anie.202102416
    RVK:
    VA 2100
    Language: English
    Publisher: Wiley
    Publication Date: 2021
    detail.hit.zdb_id: 2011836-3
    detail.hit.zdb_id: 123227-7
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  • 8
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    Online Resource
    Ultrathin and Conformable Lead Halide Perovskite Photodetector Arrays for Potential Application in Retina‐Like Vision Sensing
    Wiley ; 2021
    In:  Advanced Materials Vol. 33, No. 9 ( 2021-03)
    Details
    In: Advanced Materials, Wiley, Vol. 33, No. 9 ( 2021-03)
    Abstract: Solution‐processed lead halide perovskites are considered one of the promising materials for flexible optoelectronics. However, the array integration of ultrathin flexible perovskite photodetectors (PDs) remains a significant challenge limited by the incompatibility of perovskite materials with manufacturing techniques involving polar liquids. Here, an ultrathin (2.4 µm) and conformable perovskite‐based PD array (10 × 10 pixels) with ultralight weight (3.12 g m −2 ) and excellent flexibility, is reported. Patterned all‐inorganic CsPbBr 3 perovskite films with precise pixel position, controllable morphology, and homogenous dimension, are synthesized by a vacuum‐assisted drop‐casting patterning process as the active layer. The use of waterproof parylene‐C film as substrate and encapsulation layer effectively protects the perovskite films against penetration of polar liquids during the peeling‐off process. Benefitting from the encapsulation and ultrathin property, the device exhibits long‐term stability in the ambient environment, and robust mechanical stability under bending or 50% compressive strain. More importantly, the ultrathin flexible PD arrays conforming to hemispherical support realize imaging of light distribution, indicating the potential applications in retina‐like vision sensing.
    Type of Medium: Online Resource
    ISSN: 0935-9648 , 1521-4095
    URL: Issue
    URL: Article
    DOI: 10.1002/adma.v33.9
    DOI: 10.1002/adma.202006006
    RVK:
    UA 1538
    Language: English
    Publisher: Wiley
    Publication Date: 2021
    detail.hit.zdb_id: 1474949-X
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  • 9
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    Online Resource
    Flexible Photodetector Arrays Based on Patterned CH 3 NH 3 PbI 3− x Cl x Perovskite Film for Real‐Time Photosensing and Imaging
    Wiley ; 2019
    In:  Advanced Materials Vol. 31, No. 3 ( 2019-01)
    Details
    In: Advanced Materials, Wiley, Vol. 31, No. 3 ( 2019-01)
    Abstract: The quest for novel deformable image sensors with outstanding optoelectronic properties and large‐scale integration becomes a great impetus to exploit more advanced flexible photodetector (PD) arrays. Here, 10 × 10 flexible PD arrays with a resolution of 63.5 dpi are demonstrated based on as‐prepared perovskite arrays for photosensing and imaging. Large‐scale growth controllable CH 3 NH 3 PbI 3− x Cl x arrays are synthesized on a poly(ethylene terephthalate) substrate by using a two‐step sequential deposition method with the developed Al 2 O 3 ‐assisted hydrophilic–hydrophobic surface treatment process. The flexible PD arrays with high detectivity (9.4 × 10 11 Jones), large on/off current ratio (up to 1.2 × 10 3 ), and broad spectral response exhibit excellent electrical stability under large bending angle (θ = 150°) and superior folding endurance after hundreds of bending cycles. In addition, the device can execute the functions of capturing a real‐time light trajectory and detecting a multipoint light distribution, indicating that it has widespread potential in photosensing and imaging for optical communication, digital display, and artificial electronic skin applications.
    Type of Medium: Online Resource
    ISSN: 0935-9648 , 1521-4095
    URL: Issue
    URL: Article
    DOI: 10.1002/adma.v31.3
    DOI: 10.1002/adma.201805913
    RVK:
    UA 1538
    Language: English
    Publisher: Wiley
    Publication Date: 2019
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  • 10
    Online Resource
    Online Resource
    Urinary iodine excretion ( UIE ) estimated by iodine/creatinine ratio from spot urine in Chinese school‐age children
    Wiley ; 2017
    In:  Clinical Endocrinology Vol. 86, No. 4 ( 2017-04), p. 628-633
    Details
    In: Clinical Endocrinology, Wiley, Vol. 86, No. 4 ( 2017-04), p. 628-633
    Abstract: To assess the validity of urinary iodine excretion ( UIE ) estimated by urinary iodine/creatinine ratio ( UI /Cr) from spot urines in Chinese school‐age children. Design A cross‐sectional survey was performed in which twice‐repeated collections of 24‐h urine, and spot urine samples were obtained within 1 month. Measurements Urinary iodine concentration ( UIC ), urinary creatinine concentration ( UC r), urine volume (Uvol) of spot and 24‐h urine samples were measured. Measured 24‐h UIE was calculated from 24‐h UIC multiplied by 24‐h Uvol, while the estimated 24‐h UIE was calculated from spot UI /Cr multiplied by 24‐h urinary creatinine excretion (24‐h UC rE). Results No significant difference was observed in 24‐h Uvol between two repeated collections ( P = 0·70), while spot UIC , 24‐h UIC , spot UI /Cr and measured 24‐h UIE were significantly different ( P 〈 0·05). The estimated 24‐h UIE was 247 (136–431) μg/day in the first collection, lower than the measured 24‐h UIE of 329 (183–536) μg/day ( P 〈 0·001), while no significant difference was observed ( P = 0·30) in the second sampling as the estimated 24‐h UIE was 355 (168–624) μg/day and the measured 24‐h UIE 350 (181–615) μg/day. The spot UIC ( r = 0·57, P 〈 0·001), spot UI /Cr ( r = 0·63, P 〈 0·001) and the estimated 24‐h UIE ( r = 0·83, P 〈 0·001) were strongly correlated with the measured 24‐h UIE in the first collection. Likewise, in the second sampling, spot UIC ( r = 0·60, P 〈 0·001), spot UI /Cr ( r = 0·72, P 〈 0·001) and the estimated 24‐h UIE ( r = 0·89, P 〈 0·001) were also correlated with measured 24‐h UIE . The Bland–Altman results indicated 95% of subjects were expected to locate within the limits of agreement ( LOA ), but showed an underestimation of the urinary iodine excretion by the estimated 24‐h UIE . In addition, moderate‐to‐good agreement was found for the estimated and measured 24‐h UIE , with kappa values of 0·55 and 0·66. Conclusions Estimated 24‐h UIE by UI /Cr ratio from spot urine could represent a valid and reliable alternative for measured 24‐h UIE in estimating iodine excretion in children.
    Type of Medium: Online Resource
    ISSN: 0300-0664 , 1365-2265
    URL: Issue
    URL: Article
    DOI: 10.1111/cen.2017.86.issue-4
    DOI: 10.1111/cen.13282
    RVK:
    XA 10000
    Language: English
    Publisher: Wiley
    Publication Date: 2017
    detail.hit.zdb_id: 2004597-9
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