Radical cascade cyclizations of o‐allyloxybenzaldehydes have emerged as a powerful strategy for the synthesis of 3‐substituted chroman‐4‐ones. This minireview summarizes the incorporation of various ...functional groups into the C3‐position of chroman‐4‐ones by employing appropriate radical precursors through transition‐metal‐free systems, silver‐catalyzed systems, or visible‐light‐promoted systems.
This minireview summarizes radical reactions for incorporating various functional groups into the C3‐position of chroman‐4‐ones. The generation of radicals can be accomplished using transition metal free systems, silver‐based systems, or photoredox catalysts under visible‐light irradiation.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Microwave-assisted synthesis of polyheterocyclic-fused quinoline-2-thiones through the annulation of
ortho
-heteroaryl anilines and CS
2
was realized in water without using any catalysts and ...additives. The desired products were obtained in high yields through simple filtration. A remarkable
E
-factor of 0.45 and an EcoScale score of 85.5 were obtained.
Microwave-assisted synthesis of polyheterocyclic-fused quinoline-2-thiones through the annulation of
ortho
-heteroaryl anilines and CS
2
was realized in water without using any catalysts and additives.
A Cu-Fe bimetallic hydrogel (2-QF-CuFe-G) was constructed through a simple method. The 2-QF-CuFe-G metallohydrogel possesses excellent peroxidase-like activity to catalyze the oxidation of ...3,3′,5,5′-tetramethylbenzidine (TMB) in the presence of H
2
O
2
. The catalytic mechanism was confirmed by the addition of
*
OH radical scavenger isopropyl alcohol (IPA),
tert
-butyl alcohol (TBA) and &z.rad;OH trapping agent terephthalic acid (TA). Remarkably, the resultant blue ox-TMB system can be used to selectively and sensitively detect ascorbic acid (AA) with an LOD of 0.93 μM in the range of 4-36 μM through the colorimetric method. Moreover, the assay based on the 2-QF-CuFe-G metallohydrogel can be successfully applied to detect AA in fresh fruits.
A Cu-Fe bimetallic hydrogel (2-QF-CuFe-G) with excellent peroxidase-like activity was constructed through a simple method.
Here, an integrated cascade nanozyme with a formulation of Pt@PCN222-Mn is developed to eliminate excessive reactive oxygen species (ROS). This nanozyme mimics superoxide dismutase by incorporation ...of a Mn-5,10,15,20-tetrakis(4-carboxyphenyl)porphyrinato-based metal-organic framework compound capable of transforming oxygen radicals to hydrogen peroxide. The second mimicked functionality is that of catalase by incorporation of Pt nanoparticles, which catalyze hydrogen peroxide disproportionation to water and oxygen. Both in vitro and in vivo experimental measurements reveal the synergistic ROS-scavenging capacity of such an integrated cascade nanozyme. Two forms of inflammatory bowel disease (IBD; i.e., ulcerative colitis and Crohn's disease) can be effectively relieved by treatment with the cascade nanozyme. This study not only provides a new method for constructing enzyme-like cascade systems but also illustrates their efficient therapeutic promise in the treatment of in vivo IBDs.
The construction of smart materials, especially white light emitting (WLE) hydrogels with multi-stimuli responsive properties, has received widespread attention from researchers. In this study, a WLE ...hydrogel was obtained by the
in situ
doping of Eu
3+
and Tb
3+
into a blue emission low molecular weight gelator (MPF). Remarkably, the prepared WLE hydrogel possessed excellent stimuli responsiveness to pH, temperature and chemicals, and could be used as a soft thermometer and a selective sensor for Cu
2+
. The correlated color temperature of the WLE hydrogel was calculated to be 5063 K, suggesting a potential application in cool white light. Moreover, a series of metallohydrogels with different colors were obtained by modulating the ratio of MPF, Eu
3+
and Tb
3+
or changing the excitation wavelength, which was an excellent candidate to construct soft materials of a full-color system. Additionally, the WLE hydrogel could be used for constructing anti-counterfeiting materials. Therefore, this study provides a new approach for preparing smart WLE hydrogels with multiple functions.
White light emitting (WLE) soft materials with multi-stimuli responsive properties were constructed. The prepared WLE hydrogels can be used for environmental sensing and anti-counterfeiting.
In this study, we have synthesized a facile tyrosine derivative based compound (2-QY), which can act both as a gelator and a reducing agent. 2-QY can assemble to form a functional metallohydrogel ...(2-QY-Au) in the presence of HAuCl
4
under mild conditions (room temperature, aqueous solution, and simple sonication treatment). Au nanoparticles (Au NPs) can be
in situ
formed and dispersed uniformly in the gel system, which did not require an external reducing agent and a stabilizing agent. The obtained 2-QY-Au NP@metallohydrogel can be used as a catalyst to degrade a variety of dyes, such as methyl orange, methyl green, reactive black 5, reactive orange 16, and
p
-nitrophenol. In particular, it exhibits excellent catalytic activity towards degradation of methylene blue in the presence of NaBH
4
, with a
k
app
value (13.23 ± 0.21 s
−1
) higher than those of most of the reported catalysts in the literature. Moreover, 2-QY-Au NPs have good biocompatibility and exhibit antibacterial activity against
E. coli
and
B. subtilis
. Therefore, the 2-QY-Au NP@metallohydrogel could be used as an effective catalyst for the degradation of pollution containing organic dyes, as well as for potential applications in the biomedical field.
The X-ray crystal structure of F43Y/T67R myoglobin revealed unique Tyr-heme double cross-links between Tyr43 and the heme 4-vinyl group, which represents a novel post-translational modification of ...heme proteins. Moreover, with the feature of a distal His-Arg pair, the designed artificial enzyme exhibited a peroxidase activity comparable to that of native peroxidases, such as the most efficient horseradish peroxidase.
A rationally designed enzyme of F43Y/T67R myoglobin formed unique Tyr-heme double cross-links between Tyr43 and the heme 4-vinyl group, and exhibited a peroxidase activity comparable to that of native peroxidases.
Cyclin D1 was an important molecular involved in the pathological process of osteoarthritis (OA). The purpose of this study was to identify the effect and potential mechanism of Cyclin D1 for the ...proliferation and apoptosis of OA chondrocytes.
We used polymerase chain reaction (PCR) method to identify the expression levels of Cyclin D1 and down-stream Wnt/β-catenin pathway-related genes in OA chondrocytes according to the grade of OA. Small interfering RNA (siRNA) or overexpression of Cyclin D1 were used to identify the role of Cyclin D1 in cell proliferation and apoptosis. Next, we used XAV-939 to inhibit the Wnt/β-catenin pathway and explore the relevant mechanism.
Cyclin D1 was significantly decreased with OA grade (p < .05). After siCyclin D1 transfection, the expression level of WNT3 and nuclear β-catenin were significantly increased, while Wnt10a and total β-catenin were not obviously changed. Co-cultured with XAV-939 and siCyclin D1 abolished the effects of siCyclin D1 on proliferation and apoptosis of OA chondrocytes (p < .05).
Cyclin D1 regulated chondrocyte proliferation and apoptosis through Wnt3/β-catenin instead of Wnt10a/β-catenin signalling pathway.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Metallohydrogels are attractive biomaterials, whereas formation of a selective bimetallogel in aqueous solution has rarely been explored. In this study, we show that a phenylalanine derivative ...containing a 4‐pyridine group can not only assemble to form single crystals with copper acetate, but also selectively generate a Cu‐Ag bimetallohydrogel upon further addition of silver nitrate, which exhibits excellent multi‐responsiveness. This study represents a novel example of a selective bimetallohydrogel in aqueous solution, which provides insights into the formation of a bimetallohydrogel and clues for future design of more functional biomaterials.
A copper‐silver hydrogel: A phenylalanine derivative containing a 4‐pyridine group can construct not only single crystals, but also a novel selective Cu–Ag bimetallohydrogel in aqueous solution.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Developing efficient and safe antibacterial agents to inhibit pathogens including Physalospora piricola and Staphylococcus aureus is of great importance. Herein, a novel compound composed of Rosa ...roxburghii procyanidin, chitosan and selenium nanoparticle (RC-SeNP) was bio-synthesized, with the average diameter and zeta potential being 84.56 nm and -25.60 mV, respectively. The inhibition diameter of the RC-SeNP against P. piricola and S. aureus reached 18.67 mm and 13.13 mm, and the maximum scavenging activity against DPPH and ABTS reached 96.02% and 98.92%, respectively. Moreover, the RC-SeNP completely inhibited the propagation P. piricola and S. aureus on actual apples, suggesting excellent in vivo antimicrobial capacity. The transcriptome analysis and electron microscope observation indicated that the antibacterial activity would be attributed to adhering to and crack the cell walls as well as damage the cytomembrane and nucleus. Moreover, the RC-SeNP effectively maintained the vitamin C, total acid, and water contents of red bayberry, demonstrating potential application for fruit preservation. At last, the RC-SeNP showed no cell toxicity and trace selenium residual dose (0.03 mg/kg on apple, 0.12 mg/kg on red bayberry). This study would enlighten future development on novel nano-bioantibacterial agents for sustainable agriculture.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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