Cogent Chemistry最新文献_第3页

Green tea leaves mediated ZnO nanoparticles and its antimicrobial activity 绿茶介导氧化锌纳米颗粒及其抑菌活性研究

Cogent Chemistry Pub Date : 2018-01-01 DOI: 10.1080/23312009.2018.1469207

S. Irshad, A. Salamat, A. A. Anjum, S. Sana, Rahman S. Z. Saleem, A. Naheed, A. Iqbal

{"title":"Green tea leaves mediated ZnO nanoparticles and its antimicrobial activity","authors":"S. Irshad, A. Salamat, A. A. Anjum, S. Sana, Rahman S. Z. Saleem, A. Naheed, A. Iqbal","doi":"10.1080/23312009.2018.1469207","DOIUrl":"https://doi.org/10.1080/23312009.2018.1469207","url":null,"abstract":"Abstract Plant-mediated synthesis of ZnO Nanoparticles (NPs) have multiple advantages over conventional synthetic methods like easy, inexpensive, eco-friendly, nontoxic by-products and no critical conditions of temperature and pressure required. In this study, 9.1 g ZnO NPs were synthesized from 230 mL of 0.2 M Zinc acetate dihydrate and 100 mL of green tea leaves extract at room temperature (25°C). The leaves extract was prepared by heating 10gm dried leaves in 100 mL of deionized distilled water at 80°C for 2 h. The synthesized ZnO NPs were dried at 40°C for 24 h and calcined at 100°C for 1 h. The agar well diffusion method was used to evaluate ZnO NPs for antimicrobial activity of selected pathogenic strains. A clear zo“ne of inhibition was measured; 40.05 mm ± 0.137 for Staphylococcus aureus, 36.15 mm ± 0.304 for Escherichia coli and 40.10 mm ± 0.050 for Aspergillus niger that were comparably better results than standard antibiotic Gentamycin that showed 25 and 26 mm zone of inhibition for Staphylococcus aureus and Escherichia coli respectively. The minimum inhibitory concentration scored as 9.765µg ± 0.00, 9.531µg ± 0.00 and 5000µg ± 0.00 for Staphylococcus aureus, Escherichia Coli and Aspergillus niger respectively, was documented low concentration than reported so far concentrations of green tea ZnO NPs.","PeriodicalId":10640,"journal":{"name":"Cogent Chemistry","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/23312009.2018.1469207","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44077371","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 49

Bioactive compounds of freshly harvested open pollinated varieties (OPV) of orange maize (zea mays): Varietal, maturity, and boiling methods effects 新鲜收获的橙玉米(zea mays)开放授粉品种(OPV)的生物活性化合物:品种，成熟度和煮沸方法的影响

Cogent Chemistry Pub Date : 2018-01-01 DOI: 10.1080/23312009.2018.1507489

E. Alamu, B. Maziya-Dixon, A. Menkir, O. Olaofe

{"title":"Bioactive compounds of freshly harvested open pollinated varieties (OPV) of orange maize (zea mays): Varietal, maturity, and boiling methods effects","authors":"E. Alamu, B. Maziya-Dixon, A. Menkir, O. Olaofe","doi":"10.1080/23312009.2018.1507489","DOIUrl":"https://doi.org/10.1080/23312009.2018.1507489","url":null,"abstract":"Abstract Biofortified open pollinated maize varieties (OPV) could be used to address the problem of micronutrient deficiencies in developing countries. This study aimed at investigating the effects of maturity 20, 27, and 34 days after pollination (DAP) and processing (boiling with and without husks) on the bioactive components (carotenoids, phytic acid, tannins, and vitamin C) on fresh orange OPV maize. The fresh and processed samples were analysed for bioactive components using standard methods of analysis. Carotenoids, phytate, and vitamin C showed a general significant (P ≥ 0.5) increase in concentrations across the studied harvest maturity stages. The optimum retention for most bioactive compounds was found at 27 DAP for cobs of orange OPV maize boiled with and without husks. Boiled maize with husks showed higher retention of most bioactive compounds than boiled maize without husks where the mean concentrations of the bioactive compounds increased across the harvesting stages except for tannin and vitamin C that showed a decrease at 34 DAP. Varieties 1 and 5 showed a higher provitamin A value than the grand mean of 6.04 μg/g at 27 DAP but variety 5 had the highest concentration of 10.2 μg/g. Variety 1 showed a higher concentration of provitamin A value than the respective grand mean at the three harvest maturity stages for OPV maize boiled with husk intact. The retention of more bioactive compounds during boiling with or without husks is found to be genotype dependent. The information from this study could guide the food scientists, nutritionists, and consumers on the best boiling methods to process OPV orange maize for optimum retention of bioactive components. GRAPHICAL ABSTRACT","PeriodicalId":10640,"journal":{"name":"Cogent Chemistry","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/23312009.2018.1507489","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44320836","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4

A hexacationic coordination compound from Co(II) and a cationic ligand derived from 4,4ʹ-bipyridine: Synthesis, characterization and investigation for biological application 钴（II）与4,4-联吡啶阳离子配体的六阳离子配位化合物的合成、表征及生物应用研究

Cogent Chemistry Pub Date : 2018-01-01 DOI: 10.1080/23312009.2018.1564162

Atakilt Abebe, Getinet Tamiru

引用次数: 7

Green synthesis of silver nanoparticles using Zanthoxylum chalybeum and their antiprolytic and antibiotic properties 利用花椒合成纳米银颗粒及其抗腐殖质和抗菌素特性

Cogent Chemistry Pub Date : 2018-01-01 DOI: 10.1080/23312009.2018.1538547

C. Mahamadi, Tinashe. Wunganayi

{"title":"Green synthesis of silver nanoparticles using Zanthoxylum chalybeum and their antiprolytic and antibiotic properties","authors":"C. Mahamadi, Tinashe. Wunganayi","doi":"10.1080/23312009.2018.1538547","DOIUrl":"https://doi.org/10.1080/23312009.2018.1538547","url":null,"abstract":"Abstract In the present study, silver nanoparticles were synthesized using aqueous extract of Zanthoxylum chalybeum roots. The root extract was used both as the silver salt reducing agent as well as the post-synthesis stabilizing agent. The synthesis of the silver nanoparticles was optimized for pH, time, Z. chalybeum extract concentration, silver nitrate concentration, and temperature. The shape, morphology and size of the synthesized silver nanoparticles were characterized using UV-vis spectrometry, Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscope (TEM), whilst elemental analysis was performed using Energy dispersive X-ray spectroscopy (EDS). Investigation of anti-proteolytic activity of the silver nanoparticles using egg albumin showed that the particles inhibited digestion of albumin by Bitis arietans snake venom. The minimum concentration of silver nanoparticles required for 100% inhibition of the proteolytic activity was 3.28 mg/L. Antimicrobial activity of the silver nanoparticles against both gram positive (Bacillus subtilis) and gram negative (Escherichia coli and Pseudomonas aeruginosa) bacterial strains was confirmed by zone of inhibition observed for the strains. The findings of this work show that Z. chalybeum-mediated silver nanoparticles have great potential both as anti-snake venom and antibacterial agents.","PeriodicalId":10640,"journal":{"name":"Cogent Chemistry","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/23312009.2018.1538547","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45186794","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 5

Development and validation of RP-HPLC method for simultaneous estimation of sulfadoxine and pyrimethamine in tablet dosage form using diclofenac as internal standard 以双氯芬酸为内标同时测定片剂中磺胺多辛和乙胺嘧啶含量的反相高效液相色谱方法的建立与验证

Cogent Chemistry Pub Date : 2018-01-01 DOI: 10.1080/23312009.2018.1472198

Akwasi Acheampong, A. Gyebi, Godfred Darko, J. Apau, Wilfred Owusu Gyasi, Sylvester Addai-Arhin

{"title":"Development and validation of RP-HPLC method for simultaneous estimation of sulfadoxine and pyrimethamine in tablet dosage form using diclofenac as internal standard","authors":"Akwasi Acheampong, A. Gyebi, Godfred Darko, J. Apau, Wilfred Owusu Gyasi, Sylvester Addai-Arhin","doi":"10.1080/23312009.2018.1472198","DOIUrl":"https://doi.org/10.1080/23312009.2018.1472198","url":null,"abstract":"Abstract Sulfadoxine and pyrimethamine are often formulated together and used in the treatment of malaria especially in pregnant women serving as a prophylaxis. A new simple, precise and accurate reverse-phase high-performance liquid chromatography (RP-HPLC) method has been developed for simultaneous identification and quantification of sulfadoxine and pyrimethamine in tablet dosage form. The analysis was carried out on Waters uBondapak C18 Column (39 × 300 mm, 3.6 µm) with acetonitrile: phosphate buffer (75:25 v/v) as the mobile phase at pH of 2.5, and a flow rate of 1.0 mL/min and a detection wavelength of 230 nm. Sulfadoxine and pyrimethamine eluted at mean times of 2.86 and 3.60 min, respectively. The method was linear with r2 values of 0.9976 and 0.9841 for sulfadoxine and pyrimethamine, respectively (range 31.25–500 µg/mL). The method was accurate (97.06 ± 2.23% and 99.81 ± 1.93% for sulfadoxine and pyrimethamine, respectively), precise, specific, robust, sensitive and cost effective. The developed and validated method was used to assay two brands of tablets containing sulfadoxine and pyrimethamine. The use of internal standard, diclofenac, permitted accurate quantification of the two active pharmaceutical ingredients (APIs) and also aided in decreasing inherent errors while compensating for small variations in peak areas due to sample size fluctuations and variable detector sensitivity. The validated method can be used in routine quality control analysis of fixed-dose combination tablets containing both sulfadoxine and pyrimethamine.","PeriodicalId":10640,"journal":{"name":"Cogent Chemistry","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/23312009.2018.1472198","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44692641","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 5

Exposure to bisphenol A, bisphenol F, and bisphenol S can result in obesity in human body 暴露于双酚A、双酚F和双酚S会导致人体肥胖

Cogent Chemistry Pub Date : 2018-01-01 DOI: 10.1080/23312009.2018.1506601

J. Apau, Akwasi Acheampong, Eric Adua

引用次数: 17

Assessment of microbiological, physicochemical, water-soluble anions and elemental contents of water and sediments of Bon Accord Dam, South Africa 南非邦雅阁大坝水和沉积物中微生物、理化、水溶性阴离子和元素含量的评价

Cogent Chemistry Pub Date : 2018-01-01 DOI: 10.1080/23312009.2018.1560858

K. Mekonnen, M. P. Seopela, N. Mokgalaka, R. McCrindle

{"title":"Assessment of microbiological, physicochemical, water-soluble anions and elemental contents of water and sediments of Bon Accord Dam, South Africa","authors":"K. Mekonnen, M. P. Seopela, N. Mokgalaka, R. McCrindle","doi":"10.1080/23312009.2018.1560858","DOIUrl":"https://doi.org/10.1080/23312009.2018.1560858","url":null,"abstract":"Abstract Due to the scarcity of water resources, South Africa is mainly dependent on water stored in man-made reservoirs for urban, industrial and irrigation purposes. Hence, the quality of the water in these dams is important. The microbiological, physicochemical and elemental quality of water and sediment of Bon Accord Dam, South Africa were studied. The total coliform and Escherichia coli were measured, the physicochemical parameters were determined in situ and elemental analyses were carried out. The water from some sampling sites had pH>8.4, which could affect crop quality and yield. The electrical conductivity and total dissolved solid values implied that the water was of medium salinity where sensitive crops could be affected. The measured physicochemical parameters were within the national and/or international guidelines for irrigation water even if some of the parameters may have a negative impact on selected crops. The anion concentration in the water followed the order SO42->Cl−>PO43->NO3−>Br−>NO2−>F−. The concentrations of the water-soluble anions (except PO43- and at some sites NO3−) in samples were within their respective South African and/or WHO guidelines for irrigation water. However, the levels of PO43- in this study were ≥0.130 mg/L makes the dam hypertrophic. The average concentration of potentially toxic elements in the sediments of the dam was found to be moderately to heavily polluted by Cr and Ni, non-polluted to moderately polluted by Cu and non-polluted by Pb and Zn. The bacterial levels in the dam were low and can hence not be considered a problem.","PeriodicalId":10640,"journal":{"name":"Cogent Chemistry","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/23312009.2018.1560858","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48106423","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Green synthesis of assembled silver nanoparticles in nano capsules of Peganum harmala L leaf extract. Antibacterial activity and conjugate investigation 骆驼蓬叶提取物纳米胶囊中组装银纳米颗粒的绿色合成。抗菌活性及偶联物研究

Cogent Chemistry Pub Date : 2018-01-01 DOI: 10.1080/23312009.2018.1532374

A. Alomari, Kout El Kloub Fares, N. Moustafa

{"title":"Green synthesis of assembled silver nanoparticles in nano capsules of Peganum harmala L leaf extract. Antibacterial activity and conjugate investigation","authors":"A. Alomari, Kout El Kloub Fares, N. Moustafa","doi":"10.1080/23312009.2018.1532374","DOIUrl":"https://doi.org/10.1080/23312009.2018.1532374","url":null,"abstract":"Abstract There are a lot of publications concerning with biosynthesis of well-separated silver nanoparticles (AgNPs) from the aqueous plant extracted lower molecular weight polyol. In this first investigation, Ph.L leaf and seed extract broths were used for “green” synthesis of assembled and well-separated AgNPs, comparatively. AgNP formation from Ag (I) ions was determined by both extract color changes, UV-Vis absorption spectra, and surface plasmon resonance (SPR). The size, size distribution, and elemental and crystalline state of the formed AgNPs were determined by electron microscopy and spectrometry. The obtained results revealed the formation of assembled poly-dispersive spherical AgNPs of size measured 52.6 nm (leaf broth) and well-separated 24.2 nm (seed broth) on average. AgNPs assembled inside diffusible nano-capsules formed from the extracted macromolecules in case of leaf extract broth. Both extracts exhibited good AgNP-protecting active ingredients according to their binding affinity to L-lysine functional groups. Further, these diffusible AgNPs exerted good and comparable antibacterial activity against Staphylococcus aureus and Escherichia coli pathogens. Our results draw attention about assembling or growth of NPs by aqueous plant extracted polyol macromolecules as simple experimental protocol.","PeriodicalId":10640,"journal":{"name":"Cogent Chemistry","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/23312009.2018.1532374","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46203566","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 17

Qualitative and quantitative analyses of methamphetamine in hair following derivatization with trifluoroacetic acid or heptafluorobutyric acid anhydride 用三氟乙酸或七氟丁酸酐衍生后头发中甲基苯丙胺的定性和定量分析

Cogent Chemistry Pub Date : 2018-01-01 DOI: 10.1080/23312009.2018.1453594

M. Forouzesh, Ahmad Shekari, Rooholah Valipour

{"title":"Qualitative and quantitative analyses of methamphetamine in hair following derivatization with trifluoroacetic acid or heptafluorobutyric acid anhydride","authors":"M. Forouzesh, Ahmad Shekari, Rooholah Valipour","doi":"10.1080/23312009.2018.1453594","DOIUrl":"https://doi.org/10.1080/23312009.2018.1453594","url":null,"abstract":"Abstract Illicit drug use and its consequence necessitate the development of identification methods for the target drugs in biological materials. Methamphetamine (MA) is a psychotropic substance with short elimination half-life in urine and blood; however, negative consequences of MA use may last for a long time. So, its diagnosis is essential even long after MA exposure. A total of 50 hair specimens were obtained from those with a history of MA abuse from addiction treatment camps. A gas chromatography–mass spectrometry (GC-MS) analysis was developed to identify MA using trifluoroacetic acid (TFA) or heptafluorobutyric acid anhydride (HFBA) as two derivatization agents. It was indicated that these subjects were 80 and 8% negative for MA following derivatization with HFBA and TFA, respectively. The limits of detection and quantitation for derivatization with TFA were 0.2 and 0.6 ng/mg. In conclusion, use of TFA in GC-MS can afford to effectively dissolve MA out of the hair matrix. This dissolving procedure has easy procurement with high applicability and validity.","PeriodicalId":10640,"journal":{"name":"Cogent Chemistry","volume":"4 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1080/23312009.2018.1453594","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"60090785","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

n-Alkane isomerization by catalysis—a method of industrial importance: An overview 催化正构烷烃异构化——一种具有工业意义的方法:综述

Cogent Chemistry Pub Date : 2018-01-01 DOI: 10.1080/23312009.2018.1514686

A. Dhar, R. Vekariya, Poonam Bhadja

引用次数: 17