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1.
Food Chem ; 373(Pt B): 131434, 2021 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-34731803

RESUMO

Colorimetric sensing is a low-cost, intuitive method for monitoring the freshness of food. We prepared a colorimetric strip sensor array by mixing different amounts of bromophenol blue (BPB) and bromocresol green (BCG). As results of NH3 simulation, the array strip turned from yellow to blue, and the number of blue spots increased with the increasing NH3, like a progress bar. Although the actual color is quite different, the color-changing trend was consistent with the simulated model calculated by a computer. The progress bar results remained stable under three lighting conditions. Furthermore, in the Cod preservation experiment, the color-changing progress of the strip sensor array is consistent with the simulation and can indicate Cod freshness while providing more distinguish levels. Therefore, a "progress bar" indicator built by this strategy possess the potential of realizing nondestructive, more accurate, and commercially available food quality monitoring through the naked eye and smart equipment recognition.

2.
J Agric Food Chem ; 69(38): 11470-11484, 2021 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-34543010

RESUMO

The development of new green fungicides based on the structural optimization of natural products can effectively solve the problems of low safety and high pathogen resistance of traditional fungicides. In this paper, based on pyrazole amide compound h-I-9 with excellent fungicidal activity discovered in the previous work, a series of l-serine-derived pyrazole amide and waltherione alkaloid-derived pyrazole ester derivatives were synthesized. The structures were successively identified by 1H NMR, 13C NMR, high-resolution mass spectrometry, and X-ray single-crystal diffraction. The in vitro and in vivo fungicidal activity screening demonstrated that compound II-5 showed a good inhibition rate against Physalospora piricola. A transmission electron microscope and fluorescence microscope observation further revealed that compound II-5 may cause damage to the cell membranes and vacuoles, and the hyphae treated with II-5 could produce obvious and easily observed blue fluorescence. The succinate dehydrogenase (SDH) enzymatic activity and molecular docking simulation indicated that compounds I-3 and I-4 may be potential SDH inhibitors against Alternaria sp.


Assuntos
Alcaloides , Produtos Biológicos , Fungicidas Industriais , Alcaloides/farmacologia , Amidas/farmacologia , Produtos Biológicos/farmacologia , Ésteres , Fungicidas Industriais/farmacologia , Simulação de Acoplamento Molecular , Estrutura Molecular , Pirazóis/farmacologia , Serina , Relação Estrutura-Atividade , Succinato Desidrogenase/metabolismo
3.
Carbohydr Polym ; 271: 118427, 2021 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-34364567

RESUMO

In recent years, chitosan-based biomaterials have been continually and extensively researched by using layer-by-layer (LBL) assembly, due to their potentials in biomedicine. Various chitosan-based LBL materials have been newly developed and applied in different areas along with the development of technologies. This work reviews the recent advances of chitosan-based biomaterials produced by LBL assembly. Driving forces of LBL, for example electrostatic interactions, hydrogen bond as well as Schiff base linkage have been discussed. Various forms of chitosan-based LBL materials such as films/coatings, capsules and fibers have been reviewed. The applications of these biomaterials in the field of antimicrobial applications, drug delivery, wound dressings and tissue engineering have been comprehensively reviewed.

4.
J Agric Food Chem ; 69(23): 6423-6430, 2021 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-34085526

RESUMO

Nicotinic acid, also known as niacin, is a natural product, which is widely found in plants and animals. To discover novel natural-product-based herbicides, a series of N-(arylmethoxy)-2-chloronicotinamides were designed and synthesized. Some of the new N-(arylmethoxy)-2-chloronicotinamides exhibited excellent herbicidal activity against Agrostis stolonifera (bentgrass) at 100 µM. Compound 5f (2-chloro-N-((3,4-dichlorobenzyl)oxy)nicotinamide) possessed excellent herbicidal activity against Lemna paucicostata (duckweed), with an IC50 value of 7.8 µM, whereas the commercial herbicides clomazone and propanil had values of 125 and 2 µM, respectively. The structure-activity relationships reported in this paper could be used for the development of new herbicides against monocotyledonous weeds.


Assuntos
Herbicidas , Niacina , Herbicidas/farmacologia , Niacina/farmacologia , Niacinamida/análogos & derivados , Plantas Daninhas , Relação Estrutura-Atividade
5.
J Agric Food Chem ; 69(25): 6968-6980, 2021 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-34137594

RESUMO

It is important to discover new pesticides with new modes of action because of the increasing evolution of pesticide resistance. In this study, a series of novel pyrimidin-4-amine derivatives containing a 5-(trifluoromethyl)-1,2,4-oxadiazole moiety were designed and synthesized. Their structures were confirmed by 1H NMR, 13C NMR, and HRMS. Bioassays indicated that the 29 compounds synthesized possessed excellent insecticidal activity against Mythimna separata, Aphis medicagini, and Tetranychus cinnabarinus and fungicidal activity against Pseudoperonospora cubensis. Among these pyrimidin-4-amine compounds, 5-chloro-N-(2-fluoro-4-(5-(trifluoromethyl)-1,2,4-oxadiazol-3-yl)benzyl)-6-(1-fluoroethyl)pyrimidin-4-amine (U7) and 5-bromo-N-(2-fluoro-4-(5-(trifluoromethyl)-1,2,4-oxadiazol-3-yl)benzyl)-6-(1-fluoroethyl) pyrimidin-4-amine(U8) had broad-spectrum insecticidal and fungicidal activity. The LC50 values were 3.57 ± 0.42, 4.22 ± 0.47, and 3.14 ± 0.73 mg/L for U7, U8, and flufenerim against M. separata, respectively. The EC50 values were 24.94 ± 2.13, 30.79 ± 2.21, and 3.18 ± 0.21 mg/L for U7, U8, and azoxystrobin against P. cubensis, respectively. The AChE enzymatic activity testing revealed that the enzyme activities of compounds U7, U8, and flufenerim are 0.215, 0.184, and 0.184 U/mg prot, respectively. The molecular docking results of compounds U7, U8, and flufenerim with the AChE model demonstrated the opposite docking mode between compound U7 or U8 and positive control flufenerim in the active site of AChE. The structure-activity relationships are also discussed. This work provided excellent pesticide for further optimization. Density functional theory analysis can potentially be used to design more active compounds.


Assuntos
Inseticidas , Praguicidas , Aminas , Animais , Inseticidas/farmacologia , Simulação de Acoplamento Molecular , Estrutura Molecular , Oxidiazóis/farmacologia , Relação Estrutura-Atividade
6.
Int J Mol Sci ; 22(5)2021 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-33673430

RESUMO

To discover new compounds with broad spectrum and high activity, we designed a series of novel benzamides containing 1,2,4-oxadiazole moiety by bioisosterism, and 28 benzamides derivatives with antifungal activity were synthesized. These compounds were evaluated against four fungi: Botrytis cinereal, FusaHum graminearum, Marssonina mali, and Thanatephorus cucumeris. The results indicated that most of the compounds displayed good fungicidal activities, especially against Botrytis cinereal. For example, 10a (84.4%), 10d (83.6%), 10e (83.3%), 10f (83.1%), 10i (83.3%), and 10l (83.6%) were better than pyraclostrobin (81.4%) at 100 mg/L. In addition, the acute toxicity of 10f to zebrafish embryo was 20.58 mg/L, which was classified as a low-toxicity compound.


Assuntos
Antifúngicos/farmacologia , Benzamidas/farmacologia , Oxidiazóis/farmacologia , Peixe-Zebra/microbiologia , Animais , Ascomicetos/efeitos dos fármacos , Basidiomycota/efeitos dos fármacos , Benzamidas/síntese química , Benzamidas/química , Benzamidas/toxicidade , Botrytis/efeitos dos fármacos , Embrião não Mamífero/efeitos dos fármacos , Embrião não Mamífero/microbiologia , Fusarium/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Oxidiazóis/síntese química , Oxidiazóis/química , Oxidiazóis/toxicidade , Peixe-Zebra/embriologia
7.
Carbohydr Polym ; 251: 117084, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33142625

RESUMO

Many anti-counterfeiting inks have been explored recently, most of them are commonly involved in weak fastness, high cost and long-term toxicity, impeding their real-life applications. Herein, an environment-friendly and inexpensive anti-counterfeiting ink with excellent fastness is reported. The untifake ink is developed by combining hybrid dots (silicon/carbon) with hydroxyethyl cellulose (HEC) binder. Interestingly, the HEC binder can effectively prevent from aggregation-induced quenching of hybrid dots. Subsequently, the customized patterns are successfully transferred onto different surfaces of various substrates including cotton fabric, cellulosic paper, glass, metal, silicon wafer and PET film, using the as-prepared ink by screen-printing technique, exhibiting that the hybrid dots/HEC ink possesses widespread practicability. Notably, fluorescent color of these patterns can be switchable by adjusting environmental pH-value, further imparting the as-prepared ink with excellent covert performance. This new fluorescent hybrid dots/HEC ink will be promising candidates for high-level anti-counterfeiting applications including food packaging, apparel and documents.


Assuntos
Celulose/análogos & derivados , Celulose/química , Corantes/química , Crime/prevenção & controle , Excipientes/química , Fraude , Impressão/instrumentação , Tinta
8.
Drug Des Devel Ther ; 14: 4251-4261, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33116413

RESUMO

Objective: The protective effects of epigallocatechin gallate (EGCG) on interleukin-1ß (IL-1ß)-induced apoptosis were investigated in murine MIN6 pancreatic ß-cells. The role of uncoupling protein-3 (UCP3) signaling in this process was also explored. Methods: After treatment with IL-1ß and EGCG, cells were collected and analyzed. Cell viability was measured using the CCK8 assay and the function of ß-cells was evaluated by analyzing insulin secretion. Detection of mitochondrial function in cells was performed by measuring mitochondrial membrane potential, the concentration of ATP and activity of ROS. Apoptosis was analyzed by Hochest33258 staining and flow cytometry. Expression levels of UCP3 were interrogated using immunohistochemistry, RT-PCR and Western blotting. Results: Compared with the control group, IL-1ß treatment (20nM) for 24 h significantly decreased cell viability and insulin secretion, damaged mitochondrial function and increased ROS activity. Results also showed increased apoptosis and a decrease in UCP3 expression levels (p<0.01). However, treatment with low (1mM) or high (5mM) concentrations of EGCG significantly decreased IL-1ß-induced apoptosis (p<0.01), restored mitochondrial function and subsequently increased UCP3 levels in IL-1ß-induced ß-cells (p<0.01). Conclusion: These results suggest that EGCG protects against IL-1ß-induced mitochondrial injury and apoptosis in ß-cells through the up-regulation of UCP3.


Assuntos
Apoptose/efeitos dos fármacos , Catequina/análogos & derivados , Interleucina-1beta/antagonistas & inibidores , Interleucina-1beta/farmacologia , Ilhotas Pancreáticas/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Proteína Desacopladora 3/efeitos dos fármacos , Trifosfato de Adenosina/metabolismo , Animais , Catequina/farmacologia , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Humanos , Insulina/metabolismo , Ilhotas Pancreáticas/citologia , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Camundongos , Mitocôndrias/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Proteína Desacopladora 3/biossíntese
9.
Nan Fang Yi Ke Da Xue Xue Bao ; 40(9): 1353-1358, 2020 Sep 30.
Artigo em Chinês | MEDLINE | ID: mdl-32990220

RESUMO

OBJECTIVE: To investigate the clinical outcomes of patients with aneurysmal subarachnoid hemorrhage (aSAH) after surgeries in Yunnan Province. METHODS: We retrospectively analyzed the demographic features, vascular risk factors, severity at admission, and aneurysm locations in 85 patients with aSAH receiving surgical interventions in Yunnan Province. All the patients were treated by aneurysm clipping or coiling and followed up for clinical outcomes and recovery of daily activities evaluated by modified Rankin Scale (mRS) and Activities of Daily Living (ADL) scale, respectively. RESULTS: Thirty-four of the patients (40.0%) underwent aneurysm clipping and 51 (60.0%) underwent aneurysm coiling. During a median follow- up period of 66.23 months (IOR, 12.03 months), 84.7% of the patients had low mRS scores, and 78.8% lived independently. The WFNS grade at admission was significantly correlated with the follow-up mRS scores (95%CI: 1.48-19.09, P=0.011) and ADL (95%CI: 2.55-28.77, P < 0.001). Multivariate analysis showed that age (95%CI: 1.02-1.23, P=0.017; 95%CI: 1.00-1.15, P=0.038) and a high WFNS grade at admission (95%CI: 2.19-141.48, P=0.007; 95%CI: 2.84-82.61, P=0.002) were independent predictors of both mRS and ADL scores at follow-up. There was no significant difference in clinical outcomes or the length of hospital stay between the two treatment strategies (P > 0.05), but the cost of hospitalization was significantly higher in coiling group than in the clipping group (P < 0.001). CONCLUSIONS: Both aging and a high WFNS grade at admission are associated with a poor prognosis of aSAH, for which aneurysm clipping and coiling have similar long- term outcomes, but for patients with a high WFNS score, aneurysm clipping is favored over coiling in terms of health economics.


Assuntos
Aneurisma Intracraniano/cirurgia , Hemorragia Subaracnóidea , Atividades Cotidianas , Idoso , China/epidemiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Hemorragia Subaracnóidea/cirurgia , Resultado do Tratamento
10.
Molecules ; 25(15)2020 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-32752024

RESUMO

To find pesticidal lead compounds with high activity, a series of novel benzamides substituted with pyridine-linked 1,2,4-oxadiazole were designed by bioisosterism, and synthesized easily via esterification, cyanation, cyclization and aminolysis reactions. The structures of the target compounds were confirmed by 1H-NMR, 13C-NMR and HRMS. The preliminary bioassay showed that most compounds had good larvicidal activities against mosquito larvae at 10 mg/L, especially compound 7a, with a larvicidal activity as high as 100%, and even at 1 mg/L was still 40%; at 50 mg/L, all the target compounds showed good fungicidal activities against the eight tested fungi. Moreover, compound 7h exhibited better inhibitory activity (90.5%) than fluxapyroxad (63.6%) against Botrytis cinereal. Therefore, this type of compound can be further studied.


Assuntos
Benzamidas/química , Inseticidas/síntese química , Oxidiazóis/química , Piridinas/química , Animais , Antifúngicos/síntese química , Antifúngicos/química , Antifúngicos/farmacologia , Botrytis/efeitos dos fármacos , Desenho de Fármacos , Inseticidas/química , Inseticidas/farmacologia , Larva/efeitos dos fármacos , Mariposas/efeitos dos fármacos , Mariposas/crescimento & desenvolvimento , Oxidiazóis/síntese química , Oxidiazóis/farmacologia , Relação Estrutura-Atividade
11.
J Agric Food Chem ; 68(28): 7324-7332, 2020 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-32530612

RESUMO

Natural products are a source of many novel compounds with biological activity for the discovery of new pesticides and pharmaceuticals. Quinoxaline is a fused N-heterocycle in many natural products and synthetic compounds, and seven novel quinoxaline derivatives were designed and synthesized via three steps. Pesticidal activities of title quinoxaline derivatives were bioassayed. Most of these compounds had herbicidal, fungicidal, and insecticidal activities. The compounds 2-(6-methoxy-2-oxo-3-phenylquinoxalin-1(2H)-yl)acetonitrile (3f) and 1-allyl-6-methoxy-3-phenylquinoxalin-2(1H)-one (3g) were the most active herbicides and fungicides. Mode-of-action studies indicated that 3f is a protoprophyrinogen oxidase-inhibiting herbicide. Compound 3f also possessed broad-spectrum fungicidal activity against the plant pathogen Colletotrichum species. Some of these compounds also had insecticidal activity. Molecular docking and DFT analysis can potentially be used to design more active compounds.


Assuntos
Praguicidas/síntese química , Praguicidas/farmacologia , Quinoxalinas/química , Animais , Colletotrichum/efeitos dos fármacos , Colletotrichum/crescimento & desenvolvimento , Fungicidas Industriais/síntese química , Fungicidas Industriais/química , Fungicidas Industriais/farmacologia , Herbicidas/síntese química , Herbicidas/química , Herbicidas/farmacologia , Insetos/efeitos dos fármacos , Insetos/crescimento & desenvolvimento , Inseticidas/síntese química , Inseticidas/química , Inseticidas/farmacologia , Simulação de Acoplamento Molecular , Praguicidas/química , Plantas Daninhas/efeitos dos fármacos , Quinoxalinas/farmacologia , Relação Estrutura-Atividade
12.
J Enzyme Inhib Med Chem ; 35(1): 682-691, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32148108

RESUMO

Thirty-six novel threoninamide carbamate derivatives were designed and synthesised using active fragment-based pharmacophore model. Antifungal activities of these compounds were tested against Oomycete fungi Phytophthora capsici in vitro and in vivo. Interestingly, compound I-1, I-2, I-3, I-6 and I-7 exhibited moderate control effect (>50%) against Pseudoperonospora cubensis in greenhouse at 6.25 µg/mL, which is better than that of control. Meanwhile most of these compounds exhibited significant inhibitory against P. capsici. The other nine fungi were also tested. More importantly, some compounds exhibited remarkably high activities against Sclerotinia sclerotiorum, P. piricola and R. solan in vitro with EC50 values of 3.74-9.76 µg/mL. It is possible that the model is reliabile and this method can be used to discover lead compounds for the development of fungicides.


Assuntos
Amidas/farmacologia , Antifúngicos/farmacologia , Desenho de Fármacos , Fungos/efeitos dos fármacos , Treonina/farmacologia , Amidas/síntese química , Amidas/química , Antifúngicos/síntese química , Antifúngicos/química , Relação Dose-Resposta a Droga , Testes de Sensibilidade Microbiana , Estrutura Molecular , Relação Estrutura-Atividade , Treonina/síntese química , Treonina/química
13.
Soft Matter ; 16(14): 3416-3424, 2020 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-32219229

RESUMO

The introduction of structured microsphere composites into hydrogels is found to improve their mechanical strength capability. Herein, chitosan microspheres were functionalized with poly(acrylamide-co-1-benzyl-3-vinylimidazolium bromide) (CS-P(AM-G)), which was synthesized through an in situ copolymerization of acrylamide and a guest functional monomer. Supramolecular hydrogels were fabricated by dynamic host-guest interactions between guest units and the host molecule cucurbit[8]uril (CB[8]). Investigations on the mechanical properties of the hydrogels show that the tensile stress and the compress stress of the hydrogels are five times higher than those of CB[8] hydrogels without CS, and the healing efficiency of the hydrogels at room temperature is 88% after 24 h. The results show that CS microspheres serve as both polyfunctional initiating and cross-linking centers, whereas the dynamic host-guest interactions endow the hydrogels with a higher self-healing property. The process provides a novel method for the production of tough and self-healing supramolecular hydrogels with various potential applications.

14.
Pest Manag Sci ; 76(7): 2368-2378, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32022382

RESUMO

BACKGROUND: Succinate dehydrogenase (SDH) has been identified as one of the most significant targets for fungicide discovery. To date, 23 commercial SDH inhibitor (SDHI) fungicides have been approved for plant protection since the first launch of carboxin in 1966, and extensively applied to combat destructive plant fungi. RESULTS: In this project, 20 novel pyridine sulfide derivatives containing SDH-based heterocyclic amide fungicide were designed, synthesized, and characterized by proton nuclear magnetic resonance (1 H-NMR), carbon-13 (13 C)-NMR and high-resolution mass spectrometry (HRMS). In vitro fungicidal activity experiment, the target compound I-1 displayed excellent inhibitory rates against the common agricultural pathogens with half maximal effective concentration (EC50 ) values of 5.2 to 39.8 µg mL-1 . The in vivo fungicidal activities demonstrated that the compound I-1 could effectively prevent Botrytis cinerea from infecting tomato and cucumber leaves with the preventative rates of 67% and 50%. The mitochondrial membrane potential detection, SDH enzyme assay and the molecular docking simulation revealed that the mechanism of action of the compound I-1 and the relevant interactions with the target enzyme may be similar to those of the control fluopyram. CONCLUSION: The biological activity screening and validation of mechanism of action indicated that the compound I-1 could be identified as a potential SDH inhibitor for further study. © 2020 Society of Chemical Industry.


Assuntos
Ascomicetos , Fungicidas Industriais/farmacologia , Botrytis , Simulação de Acoplamento Molecular , Doenças das Plantas , Piridinas , Relação Estrutura-Atividade , Succinato Desidrogenase , Sulfetos
15.
Pest Manag Sci ; 76(3): 868-879, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31429196

RESUMO

BACKGROUND: 4-Hydroxyphenylpyruvate dioxygenase (HPPD, EC 1.13.11.27) has been a good target for herbicide discovery. In order to discover novel HPPD herbicides, a series of pyrazole aromatic ketone analogs were designed and synthesized. RESULTS: The 25 pyrazole aromatic ketone analogs synthesized were tested for herbicidal activity and compounds A1, A3, A4, A17, A20 and A25 displayed excellent herbicidal activity against Chenopodium serotinum, Stellaria media and Brassica juncea at 37.5 g ha-1 . In addition, compounds A1, A5, A9, A10, A16, A17, A20 and A25 exhibited good crop selectivity for wheat, maize and rice at 150 g ha-1 . Inhibition activities against AtHPPD proved the compounds were HPPD inhibitors. The structure-activity relationship of these pyrazole aromatic ketone analogs was studied using molecular docking. CONCLUSION: These pyrazole aromatic ketone derivatives could be used as lead structures for development of HPPD herbicides against dicotyledonous weeds with further structure modification. © 2019 Society of Chemical Industry.


Assuntos
Pirazóis/química , 4-Hidroxifenilpiruvato Dioxigenase , Herbicidas , Cetonas , Simulação de Acoplamento Molecular , Estrutura Molecular , Relação Estrutura-Atividade
16.
Talanta ; 204: 592-601, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31357339

RESUMO

Development of conjugated polymers with fluorescence sensing characteristics has received close attention from researchers in fields of environmental protection, biosensing and toxins detection on food. In this paper, novel polyaniline derivatives of poly(9-methyl-9H-carbazol-3-amine) and poly(9,9-dihexyl-9H-fluoren-2-amine) are prepared by facile chemical polymerization. Then they are characterized with NMR (Nuclear Magnetic Resonance), GPC (Gel Permeation Chromatography), XRD (X-Ray Diffraction), FT-IR (Fourier Transform Infrared spectroscopy), FL (Fluorescence spectrometry) and UV-vis (Ultraviolet-visible spectroscopy) characterizations and further applied to the fluorescence detection of different acids and amines. Moreover, the obtained poly(9-methyl-9H-carbazol-3-amine) displays excellent fluorescence properties in the detection for both acids and amines. Besides, this poly(9-methyl-9H-carbazol-3-amine) can not only be used for fluorescence detection in solution, but also can be prepared into solid state and applied in the gas phase fluorescence detection. This work has greatly expanded the scope of application to these polyaniline derivatives materials, opening a new path for the researches on multi-functional chemosensor.


Assuntos
Compostos de Anilina/química , Carbazóis/química , Fluorenos/química , Corantes Fluorescentes/química , Compostos de Anilina/síntese química , Carbazóis/síntese química , Etilenodiaminas/análise , Etilenodiaminas/química , Fluorenos/síntese química , Fluorescência , Corantes Fluorescentes/síntese química , Ácido Clorídrico/análise , Ácido Clorídrico/química , Ligação de Hidrogênio , Limite de Detecção , Metilaminas/análise , Metilaminas/química , Ácido Nítrico/análise , Ácido Nítrico/química , Reprodutibilidade dos Testes , Espectrometria de Fluorescência/métodos
17.
Pest Manag Sci ; 75(11): 2892-2900, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31050111

RESUMO

BACKGROUND: In recent years, carboxamide fungicides, targeting succinate dehydrogenase (SDH), have shown highly efficient and broad spectrum fungicidal activity. Structure-activity relationship (SAR) results for these commercial fungicides show that the carboxamide group was a key active group. This is useful information for the discovery of new pyrazole carboxamide derivatives with fungicidal activity. RESULTS: Twenty-seven novel pyrazole carboxamides were designed and synthesized. Their fungicidal activities against Gibberella zeae, Phytophthora infestans, Phytophthora capsici, Rhizoctonia solani, Alternaria solani, Botrytis cinerea, Fusarium oxysporum, Cercospora arachidicola, Sclerotinia sclerotiorum and Physalospora piricola were tested; derivatives possessed excellent inhibitory at 50 mg L-1 in particular. Furthermore, some pyrazole carboxamides exhibited remarkably high activities against Sclerotinia sclerotiorum in vitro with EC50 values of 2.04 to 15.2 µg mL-1 . In addition, some compounds also exhibited high activities against Physalospora piricola, Cercospora arachidicola and Phytophthora capsici. Inhibition activities against SDH proved that the designed analogues were effective at the enzyme level. The SAR of these pyrazole carboxamides was studied by using the docking method. CONCLUSION: It is possible that pyrazole carboxamides, which exhibit good activity against Sclerotinia sclerotiorum, can be further optimized as a lead compounds of carboxamide fungicides. © 2019 Society of Chemical Industry.


Assuntos
Ascomicetos/efeitos dos fármacos , Fungicidas Industriais/farmacologia , Fungos Mitospóricos/efeitos dos fármacos , Phytophthora infestans/efeitos dos fármacos , Pirazóis/farmacologia , Fungicidas Industriais/síntese química , Fungicidas Industriais/química , Pirazóis/síntese química , Pirazóis/química , Relação Estrutura-Atividade
18.
Nanomaterials (Basel) ; 8(12)2018 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-30544509

RESUMO

More multipurpose and convenient demand driven by Radio Frequency Identification (RFID) and intelligent packaging require flexible power sources. A VO2(B)/graphene (VO2(B)/GN) core-shell composite was successfully synthesized by the hydrothermal treatment with V2O5 and graphite. The as-obtained sample was characterized by XRD, FT-IR, SEM, TEM, and XPS measurements. In addition, the electrochemical properties of VO2(B)/GN were tested. Due to its great electrochemical performance and mechanical properties, graphene could increase the electrochemical performance and strengthen the structural stability of the material at the same time. With increasing loading amount of GN, the specific capacitance of VO2(B)/GN increased correspondingly. With 20% GN loading, the initial discharge specific capacity could reach 197 F g-1 at 0.5 A g-1, and 160 F g-1 at 1 A g-1 in 0.5 M Na2SO4 electrolyte, which is better than that of pure rod-like VO2(B). The capacitance of the VO2(B)/GN (20%) composite electrode retains 95.49% after 1000 cycles, which is higher than that of a pure VO2(B) electrode (85.43%), indicating that the VO2(B)/GN composite possesses better cycling stability. Moreover, a symmetrical solid-state supercapacitor (SCs) using VO2(B)/GN(20%) as the anode was assembled. Four printed SCs were connected in series to light up a 1.5 V red LED. This demonstrates its potential application in intelligent packaging to trace food safety.

19.
Materials (Basel) ; 11(12)2018 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-30501047

RESUMO

Colorimetric oxygen indicators can be applied for non-destructive testing in packaging; especially in modified atmosphere packaging (MAP). In this paper; titanium dioxide (TiO2) nanotube; which is used as a semiconductor photocatalyst in oxygen indicators; was synthesized via a microwave-assisted hydrothermal method. X-Ray Diffraction (XRD) was used to analyze its crystal form and Scanning Electron Microscope (SEM).to characterize its morphology. Its properties were studied using Brunauer-Emmett-Teller (BET), Diffuse Reflection Spectrum (DRS), and Bluebottle experiments. The results showed that the synthesized TiO2 nanotube was a mixture of rutile and anatase; with a specific surface area of 190.35 m²/g; and a wide band gap of 3.34 eV. Given the satisfactory performance; the TiO2-based oxygen indicator was prepared and combined with glycerol; methylene blue; and hydroxyethyl cellulose (HEC). The oxygen indicator demonstrated excellent photocatalytic performance and effectively avoided excitation by visible light. We studied the rheological properties; thixotropic properties; and wettability of the indicator. The results demonstrated the printability of the indicator solution; which was then printed in the polyethylene terephthalate (PET) film by screen printing and applied to MAP. The application results showed that the prepared oxygen indicator was able to provide visual support to judge whether the packaging was intact and the food was safe.

20.
Bioorg Med Chem Lett ; 27(24): 5457-5462, 2017 12 15.
Artigo em Inglês | MEDLINE | ID: mdl-29132751

RESUMO

A series of new 3-substitutedphenyl-4-substitutedbenzylideneamino-1,2,4-triazole Mannich bases and bis-Mannich bases were synthesized through Mannich reaction with high yields. Their structures were confirmed by means of IR, 1H NMR, 13C NMR and elemental analysis. The preliminary bioassay indicated that compounds 7g, 7h and 7l exhibited potent in vitro inhibitory activities against ketol-acid reductoisomerase (KARI) with Ki value of (0.38 ±â€¯0.25), (6.59 ±â€¯2.75) and (8.46 ±â€¯3.99) µmol/L, respectively, and were comparable with IpOHA. They could be new KARI inhibitors for follow-up research. Some of the title compounds also exhibited obvious herbicidal activities against Echinochloa crusgalli and remarkable in vitro fungicidal activities against Physalospora piricola and Rhizoctonia cerealis. The SAR of the compounds were analyzed, in which the molecular docking revealed the binding mode of 7g with the KARI, and the 3D-QSAR results provided useful information for guiding further optimization of this kind of structures to discover new fungicidal agents towards Rhizoctonia cerealis.


Assuntos
Antifúngicos/síntese química , Herbicidas/síntese química , Cetol-Ácido Redutoisomerase/antagonistas & inibidores , Bases de Mannich/química , Triazóis/química , Antifúngicos/química , Antifúngicos/farmacologia , Sítios de Ligação , Echinochloa/efeitos dos fármacos , Echinochloa/enzimologia , Fungos/efeitos dos fármacos , Fungos/enzimologia , Herbicidas/química , Herbicidas/farmacologia , Cetol-Ácido Redutoisomerase/metabolismo , Cinética , Simulação de Acoplamento Molecular , Estrutura Terciária de Proteína , Relação Quantitativa Estrutura-Atividade
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