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1.
A zirconium terephthalate metal‐organic framework‐incorporated poly(N‐vinylcarbazole‐co‐divinylbenzene) monolith was fabricated in a capillary by a thermal polymerization method. The optimized monolith had a homogeneous structure, good permeability, and stability. The monolith could be used for the effective enrichment of fungicides through π‐π interactions, electrostatic forces, and hydrogen bonds. The potential factors that affect the extraction efficiency, including ionic strength, solution pH, sample volume, and eluent volume, were investigated in detail. The monolith‐based in‐tube solid‐phase microextraction coupled with ultra‐high‐performance liquid chromatography and high‐resolution Orbitrap mass spectrometry was performed for the analysis of five fungicides (pyrimethanil, tebuconazole, hexaconazole, diniconazole, and flutriafol) in environmental samples. Under the optimized conditions, the linear ranges were 0.005–5 ng/mL for pyrimethanil, 0.01–5 ng/mL for flutriafol, and 0.05–5 ng/mL for other fungicides, respectively, with coefficients of determination ≥0.9911. The limits of detection were 1.34–14.8 ng/L. The columns showed good repeatability (relative standard deviations ≤9.3%, n = 5) and desirable column‐to‐column reproducibility (relative standard deviations 5.3–9.4%, n = 5). The proposed method was successfully applied for the simultaneous detection of five fungicides in water and soil samples, with recoveries of 90.4–97.5 and 84.0–95.3%, respectively.  相似文献   

2.
A high‐throughput and environmentally friendly method based on 96‐well plate thin‐film microextraction was established to determine 14 fungicides in grapes and grape juice using liquid chromatography–tandem mass spectrometry. The thin‐film microextraction optimized method consisted of 60 min of extraction at pH 6.0 with the addition of sodium chloride (2–5%). Acetonitrile/water in the ratio of 8:2 was used for desorption analytes for 60 min. Evaluation of different extractive phases showed that polyacrylonitrile–polystyrene–divinylbenzene was the optimum coating. The linearity of the method was good in the range of 0.01–0.5 μg/mL for 14 fungicides with determination coefficients (R2) from 0.990 to 0.999, which indicated good linearity for both the grape juice and grape matrixes. The limit of detection was in the range of 0.002–0.01 μg/mL. The limit of quantitation was in the range of 0.01 mg/kg according to the minimum fortified level. The average absolute recoveries of the 14 fungicides ranged from 75.0 to 118.3%. The intraday relative standard deviation (n = 4) and interday relative standard deviation (n = 4) were 5.6–13.0% and 1.6–6.4%, respectively. This study showed that this method can be used for analyzing 96 samples in parallel, and the sample preparation time was approximately 2.0 min per sample. In addition, this approach offers a green and low‐cost sample pretreatment technique for future analyses.  相似文献   

3.
A series of 3‐(thiophen‐2‐yl)‐1,5‐dihydro‐2H‐pyrrol‐2‐one derivatives bearing a carbonic ester group were designed and synthesized by integrating a thiophene nucleus and a pyrroline‐2‐one scaffold in a single molecular architecture. Their structures were confirmed by IR, 1H‐NMR, EI‐MS, and elemental analyses, and their antifungal activities against Fusarium graminearum (Fg), Rhizoctorzia solani (Rs), and Botrytis cinerea (Bc) were evaluated. The antifungal bioassays indicated that some title compounds exhibited desirable antifungal effects against the tested fungi. Strikingly, the title compounds 4i , 4k , 4n , and 4o showed obvious antifungal activities against Rs, with corresponding EC50 values of 35.26, 33.56, 23.90, and 30.48 μg/mL, respectively, which are better than that of hymexazol (37.86 μg/mL). These results indicated that 3‐(thiophen‐2‐yl)‐1,5‐dihydro‐2H‐pyrrol‐2‐one derivatives bearing a carbonic ester group can serve as potential structural templates in the search for novel high‐efficient fungicides.  相似文献   

4.
Strobilurins have become one of the most important classes of agricultural fungicides. To discover new strobilurin derivatives with high activity against resistant pathogens, a series of novel β‐methoxyacrylate analogues were designed and synthesized by integrating substituted pyrimidine with a strobilurin pharmacophore. The compounds were confirmed and characterized by infrared, 1H nuclear magnetic resonance, elemental analysis and mass spectroscopy. The bioassays indicated that most of the compounds 1 exhibited potent antifungal activity against Colletotrichum orbiculare, Botrytis cinerea Pers and Phytophthora capsici Leonian at the concentration of 50 μg/mL. Exhilaratingly, compound 1a (R=methyl) showed better antifungal activity against all the tested fungi than the commercial strobilurin fungicide azoxystrobin.  相似文献   

5.
In this study, a simple and accurate sample preparation method based on dispersive solid‐phase extraction and dispersive liquid‐liquid microextraction has been developed for the determination of seven novel succinate dehydrogenase inhibitor fungicides (isopyrazam, fluopyram, pydiflumetofen, boscalid, penthiopyrad, fluxapyroxad, and thifluzamide) in watermelon. The watermelon samples were extracted with acetonitrile, cleaned up by dispersive solid‐phase extraction procedure using primary secondary amine, extracted and concentrated by the dispersive liquid‐liquid microextraction procedure with 1,1,2,2‐tetrachloroethane, and then analyzed by ultra high performance liquid chromatography with tandem mass spectrometry. The main experimental factors affecting the performance of dispersive solid‐phase extraction and dispersive liquid‐liquid microextraction procedure on extraction efficiency were investigated. The proposed method had a good linearity in the range of 0.1–100 µg/kg with correlation coefficients (r) of 0.9979–0.9999. The limit of quantification of seven fungicides was 0.1 µg/kg in the method. The fortified recoveries of seven succinate dehydrogenase inhibitor fungicides at three levels ranged from 72.0 to 111.6% with relative standard deviations of 3.4–14.1% (n = 5). The proposed method was successfully used for the rapid determination of seven succinate dehydrogenase inhibitor fungicides in watermelon.  相似文献   

6.
A hyphenated strategy by off‐line coupling of 1,1′‐diphenyl‐2‐picrylhydrazyl‐high‐performance liquid chromatography, high‐speed countercurrent chromatography, and preparative high‐performance liquid chromatography was established to screen and separate antioxidants from ethyl acetate fraction of the roots of Polygonum multiflorum. Under the targeted guidance of 1,1′‐diphenyl‐2‐picrylhydrazyl‐high‐performance liquid chromatography experiment, 12 compounds were identified as potential antioxidants and readily isolated by high‐speed counter‐current chromatography and preparative high‐performance liquid chromatography. Ultraviolet spectroscopy, mass spectrometry, and 1H NMR spectroscopy were employed to identify their structures, which were assigned as gallic acid ( 1 , 6.2 mg, 98.28%), catechin ( 2 , 8.8 mg, 90.69%), epicatechin ( 3 , 4.1 mg, 96.71%), polydatin ( 4 , 5.3 mg, 94.91%), 2,3,5,4′‐tetrahydroxy stilbene‐2‐Οβ‐D‐glucoside ( 5 , 20.2 mg, 95.23%), piceatannol ( 6 , 5.3 mg, 96.85%), rutin ( 7 , 5.4 mg, 97.92%), resveratrol ( 8 , 5.2 mg, 96.94%), isorhapontigenin ( 9 , 11.4 mg, 94.81%), hyperoside ( 10 , 9.7 mg, 98.52%), rhein ( 11 , 4.9 mg, 97.46%), and emodin ( 12 , 8.2 mg, 95.74%). Notably, compounds 6 and 9 were isolated from Polygonum multiflorum for the first time. In addition, antioxidant activity of compounds 1–12 were evaluated, and compounds 1–8 and 10 exhibited stronger antioxidant activity than ascorbic acid (positive control). These results indicated that the proposed method is a highly efficient strategy to screen and isolate antioxidants from complex natural products.  相似文献   

7.
A series of 1‐(3‐chloropyridin‐2‐yl)‐5‐(trifluoromethyl)‐1H‐pyrazole‐4‐carboxamide derivatives which have di‐substituents on nitrogen were designed and synthesized. Bioassay results showed that all the synthetic compounds exhibited lower antifungal activities against Gibberella zeae, Cytospora mandshurica, and Fusarium oxysporum than T 3 (14.7, 21.1, and 32.7 μg/mL), but some of them exhibited better activities against Botrytis cinerea, Phytophthora infestans, and Sclerotinia sclerotiorum than T 3 (>200, >200, and >200 μg/mL); the EC50 values of 7d and 7c against B. cinerea were 94.9 and 56.2 μg/mL, respectively. The EC50 values of 7a , 7d , and 7c against S. sclerotiorum were 73.5, 78.7, and 68.5 μg/mL, respectively.  相似文献   

8.
Relatively high molecular weight S‐BINOLs with substituted functional groups were synthesized, and structures were elucidated by FTIR, 1H nuclear magnetic resonance, 13C nuclear magnetic resonance, and HRMS. As a preliminary step, the compounds were docked into the active site of phosphoinositide3‐kinase (PI3Kinase) (Protein Data Bank ID: 2IUG) that is a crucial regulator of apoptosis or programmed cell death. To ensure the PI3Kinase inhibition, because it was predicted as the most suitable bioactivity of these compounds, a competitive ELISA PI3Kinase inhibition study was carried out. Compounds 3 , 4a , 4b , and 6 were assessed for cytotoxicity/antiproliferative effects on MCF‐7 (breast cancer) and HCT116 (colon cancer) cell lines. In the docking studies, excellent binding affinities of 3 , 4a , 4b , and 6 (−11.36, −14.52, −14.86, and −21.76 kcal/mol, respectively) and the inhibitory constants (ki) (4.75 nM, 81.64 pM, 78.23 pM, and 14.24 pM, respectively) encouraged us to carry out anticancer studies further. Excellent inhibitory values were obtained in the range of 82–90% relative activity and IC50 range of 5–12 nM. In the cytotoxicity, the relative inhibition activity was remarkably found high in MCF‐7 cell lines as 89.14% ( 6 ), 82.18% ( 4b ), 80.46% ( 3 ), and 74.78% ( 4a ) with the IC50 range of 0.02–0.18 μM. No compounds were found inactive for the proposed activity in this study. The Structure Activity Relationship studies prove that compounds 3 , 4a , 4b , and 6 are specific PI3Kinase inhibitors with the competence to cure breast cancers.  相似文献   

9.
The separation of a compound of interest from its structurally similar homologues to produce high‐purity natural products is a challenging problem. This work proposes a novel method for the separation of iristectorigenin A from its structurally similar homologues by ionic‐liquid‐based ultrasound‐assisted extraction and the subsequent screening and isolation of potential α‐glucosidase inhibitors via ultrafiltration and semipreparative high‐performance liquid chromatography. Ionic‐liquid‐based ultrasound‐assisted extraction was successfully applied to the extraction of tectorigenin, iristectorigenin A, irigenin, and irisflorentin from Belamcanda chinensis . The optimum conditions for the efficient extraction of isoflavones were determined as 1.0 M 1‐ethyl‐3‐methylimidazolium tetrafluoroborate with extraction time of 30 min and a solvent to solid ratio of 30 mL/g. Ultrafiltration with liquid chromatography and mass spectrometry was applied to screen and identify α‐glucosidase inhibitors from B. chinensis , followed by the application of semipreparative high‐performance liquid chromatography to separate and isolate the active constituents. Four major compounds including tectorigenin, iristectorigenin A, irigenin, and irisflorentin were screened and identified as α‐glucosidase inhibitors, and then the four active compounds abovementioned were subsequently isolated by semipreparative high‐performance liquid chromatography (99.89, 88.97, 99.79, and 99.97% purity, respectively). The results demonstrate that ionic liquid extraction can be successfully applied to the extraction of isoflavones from B. chinensis .  相似文献   

10.
Nine novel difluoromethylpyrazole acyl urea derivatives were synthesized via seven steps conveniently. All the structures were determined by 1H‐NMR, 13C‐NMR, HRMS, and X‐ray diffraction. The in vivo fungicidal activities were determined against Corynespora mazei, Botrytis cinerea, Fusarium oxysporum, and Pseudomonas syringae, respectively. The bioassay results indicated that some of them displayed good control effective (around 50 and 80%) against P. syringae and B. cinerea at 50 mg/L, respectively, which is better than control. It is possible that difluoromethylpyrazole acyl urea derivatives can be a leading compound for the development of new fungicides against the two fungi with further structure optimization. Furthermore, docking model was studied to establish structure–activity relationship of difluoromethylpyrazole acyl urea derivatives.  相似文献   

11.
Novel sulfonamide containing diaryl pyrazoles were synthesized and were subsequently tested for their in vitro cyclooxygenase inhibitory assay. Compounds that showed promising in vitro COX‐2 IC50 values and selectivity indices were then evaluated for their in vivo anti‐inflammatory inhibition assay using standard carrageenan‐induced rat paw edema method. Two promising inhibitors were evaluated for ulcerogenic liability. X‐ray crystal structure of COX‐2 was taken from PDB entry COX‐2 (3LN1) having a resolution of 2.80 Å (Angstroms). Structural preparations for docking studies were accomplished using protein preparation wizard in Maestro 9.0. Compound 10b displayed reasonable COX‐2 inhibition (COX‐2 IC50 = 0.52 μM) and COX‐2 selectivity index (SI = 10.73) when compared with celecoxib (COX‐2 IC50 = 0.78 μM) and (SI = 9.51). In vivo anti‐inflammatory studies demonstrated 64.28% inhibition for 10b in comparison with the 57.14% for that of celecoxib itself. The results of ulcerogenic liability were also found comparable with standard celecoxib. Molecular docking studies revealed that all the designed molecules showed good interactions with receptor active site with glide scores in the range −13.130 to −10.624.  相似文献   

12.
Ten propylene‐1H‐1,2,3‐triazole‐4‐methylene‐tethered isatin‐moxifloxacin hybrids 5a–j were synthesized via Cu‐promoted azide‐alkyne cycloaddition reaction, and screened for their in vitro anti‐mycobacterial activities against Mycobacterium tuberculosis H37Rv and multidrug‐resistant tuberculosis. The results showed that all the synthesized hybrids [minimum inhibitory concentration (MIC): 0.25–4.0 μg/mL] displayed considerable activities against the tested two strains, but all less active than the parent moxifloxacin (MIC: 0.10 and 0.12 μg/mL). The resistance index of the most targets was around 1, suggesting this kind of hybrids could reduce the cross–resistance to some extent. Among them, hybrid 5 g was found most active against Mycobacterium tuberculosis H37Rv with MIC of 0.39 μg/mL, which was comparable with rifampicin (MIC: 0.39 μg/mL), while conjugate 5a (MIC: 0.25 μg/mL) was 128– > 512 times more active than rifampicin (MIC: 32 μg/mL) and isoniazid (MIC: >128 μg/mL) against multidrug‐resistant tuberculosis.  相似文献   

13.
A dispersive liquid–liquid microextraction method based on the solidification of floating organic droplets was developed as a simple and sensitive method for the simultaneous determination of the concentrations of multiple fungicides (triazolone, chlorothalonil, cyprodinil, and trifloxystrobin) in water by high‐performance liquid chromatography with variable‐wavelength detection. After an approach varying one factor at a time was used, an orthogonal array design [L25 (55)] was employed to optimize the method and to determine the interactions between the parameters. The significance of the effects of the different factors was determined using analysis of variance. The results indicated that the extraction solvent volume significantly affects the efficiency of the extraction. Under optimal conditions, the relative standard deviation (n = 5) varied from 2.3 to 5.5% at 0.1 μg/mL for each analyte. Low limits of detection were obtained and ranged from 0.02 to 0.2 ng/mL. In addition, the proposed method was applied to the analysis of fungicides in real water samples. The results show that the dispersive liquid–liquid microextraction based on the solidification of floating organic droplets is a potential method for detecting fungicides in environmental water samples, with recoveries of the target analytes ranging from 70.1 to 102.5%.  相似文献   

14.
A series of novel propylene tethered benzofuran–isatin hybrids 5a–j were designed, synthesized, and assessed for their in vitro anti‐mycobacterial activity against Mycobacterium tuberculosis (MTB) H37Rv and multidrug‐resistant (MDR)‐MTB strains. All hybrids exhibited promising anti‐mycobacterial activities against the tested two pathogens with minimum inhibitory concentration (MIC) ranging from 2 to 32 μg/mL, and the resistance index for a significant part of the hybrids was ≤1, indicating their potential for the treatment of drug‐resistant tuberculosis. Hybrid 5g (MIC: 2 and 4 μg/mL) was found to be the most active against MTB H37Rv and MDR‐MTB, which was eightfold and >32‐fold more active than the first‐line anti‐tuberculosis drugs rifampicin (MIC: 32 μg/mL) and isoniazid (MIC: >128 μg/mL) against MDR‐MTB, and it could act as a starting point for further optimization.  相似文献   

15.
A highly selective molecularly imprinted solid‐phase extraction coupled with gas chromatography method was developed for the simultaneous isolation and determination of four organochlorine fungicides (pentachloronitrobenzene, pentachloroaniline, methylpentachlorophenyl sulfide, and hexachlorobenzene) in ginseng samples. A novel molecularly imprinted polymer with pentachloronitrobenzene as template was synthesized by precipitation polymerization employing butanone/n‐heptane (6.5:3.5, v/v) solution as porogen. The limit of detection of the method was 0.001 mg/kg, and the limit of quantification was 0.002 mg/kg. The different spiked levels of ginseng samples were 0.05, 0.5, 2.0 for pentachloronitrobenzene and pentachloroaniline, and 0.01, 0.1, 1.0 for methylpentachlorophenyl sulfide and hexachlorobenzene. The average recoveries of four organochlorine fungicides were 87.6–92.3% of pentachloronitrobenzene, 79.3–95.2% of pentachloroaniline, 80.3–90.4% of methylpentachlorophenyl sulfide, and 83.5–91.7% of hexachlorobenzene, respectively. This new method could be applied to direct determination of four organochlorine fungicides in ginseng samples.  相似文献   

16.
Plant-derived compounds are emerging as an alternative choice to synthetic fungicides. Chloroform–methanol extract, obtained from the bark of Zanthoxylum rhoifolium, a member of Rutaceae, showed a fungistatic effect on Botrytis cinerea, Sclerotinia sclerotiorum, Alternaria alternata, Colletotrichum gloeosporioides and Clonostachys rosea, when added to the growth medium at different concentrations. A fraction obtained by gel separation and containing the alkaloid O-Methylcapaurine showed significant fungistatic effect against B. cinerea and S. sclerotiorum, two of the most destructive phytopathogenic fungi. The underlying mechanism of such an inhibition was further investigated in B. cinerea, a fungus highly prone to develop fungicide resistance, by analysing the expression levels of a set of genes (BcatrB, P450, CYP51 and TOR). O-Methylcapaurine inhibited the expression of all the analysed genes. In particular, the expression of BcatrB gene, encoding a membrane drug transporter involved in the resistance to a wide range of xenobiotic compounds, was strongly inhibited (91%).  相似文献   

17.
Strobilurins are a class of important agricultural fungicides that are used widely in plant protection. To find new strobilurin analogues with high activity against resistant pathogens, a series of new strobilurin derivatives bearing 1,2,4‐triazole oxime ether side chain 3a , 3b , 3c , 3d , 3e , 3f , 3g , 3h were designed and synthesized. Their structures were confirmed by IR, 1H NMR, EIMS, and elemental analyses. Bioassays indicated that some of the compounds showed good fungicidal activities in the concentration of 50 mg/L. For example, compound 3f possessed 100%, 100%, and 95.5% inhibition against Fusarium omysporum, Physalospora piricola Nose, and Gibberella saubinetii at the concentration of 50 mg/L, respectively.  相似文献   

18.
A series of novel 3‐(2‐(substituted phenyl)hydrazinylmethylidene)furan‐2,4(3H,5H)‐diones were designed and synthesized with ethyl 4‐chloroacetoacetate as the starting material. Their structures were confirmed by FT‐IR, 1H NMR, 13C NMR, EI‐MS and elemental analysis. Bioassay data demonstrated that these compounds exhibited remarkable antifungal activity against Fusarium graminearum, Botrytis cinerea, Rhizoctonia cerealis and Colletotrichum capsici. Compound 3‐(2‐(4‐bromophenyl)hydrazinylmethylidene)furan‐2,4(3H,5H)‐dione ( 5g ) had excellent bioactivity against Botrytis cinerea with an EC50 value of 0.18 μg/mL ‐ markedly lower than the 0.24 μg/mL of the commercial fungicide procymidone. The result revealed that introducing the halogenated phenylhydrazine at the 3‐position of furan‐2,4(3H, 5H)‐dione was an effective way to design new tetronic acid derivatives as new fungicides.  相似文献   

19.
A series of novel isatin‐ciprofloxacin hybrids inhaling oxime, semicarbazone, and thiosemicarbazone groups with hydrogen bonding capacity were designed, synthesized, and evaluated for their in vitro antitubercular activities against Mycobacterium tuberculosis (MTB) H37Rv and multidrug‐resistant‐TB (MDR‐TB). All hybrids endowed with potential activities against the tested MTB H37Rv and MDR‐TB strains with minimum inhibitory concentration (MIC) in a range of 0.20 to 128 μg/mL. In particular, the most active hybrid 5e (MIC: 0.20 and 0.5 μg/mL) was four and two times more active than the parent ciprofloxacin (MIC: 0.78 μg/mL) and rifampicin (MIC: 0.39 μg/mL) against MTB H37Rv, and 4–>256 times more potent than the three references ciprofloxacin (MIC: 2.0 μg/mL), rifampicin (MIC: 32 μg/mL), and isoniazid (>128 μg/mL) against MDR‐TB. Thus, this kind of hybrids holds great promise as future anti‐TB agents against both drug‐sensitive and drug‐resistant MTB strains infection.  相似文献   

20.
Molecularly imprinted polymers for strobilurin fungicides were prepared by precipitation polymerization employing azoxystrobin as template molecular together with methacrylic acid monomer and trimethylolpropane triacrylate cross‐linker. Morphological characterization showed molecularly imprinted polymers were uniform spherical particles with about 0.2 μm in diameter, while the morphologies of nonimprinted polymers were irregular bulk. The equilibrium binding and selective experiments proved that molecularly imprinted polymers possessed a higher affinity toward four fungicides compared to nonimprinted polymers and heterogeneous binding sites were found in the molecularly imprinted polymers. Molecularly imprinted solid‐phase extraction conditions, including sample loading solvents, selective washing, and elution solvents, were carefully optimized. The developed method showed good recoveries (70.0–114.0%) with relative standard deviations in range of 1.0–9.8% (n  =  3) for samples (cucumber and peach) spiked at three different levels (10, 50, and 100 μg/ kg). The detection limit (signal/noise = 3) ranged from 0.01 to 0.08 μg/kg. The results demonstrated good potential use of this convenient and highly efficient method for determining trace strobilurin fungicides in agricultural products.  相似文献   

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