African Journal of Pure and Applied Chemistry最新文献_第9页

Synthesis, characterization and thermal analysis of the copper(II) complexes with 2,2-bipyridyl and 1,10-phenanthroline 2,2-联吡啶和1,10-菲罗啉铜配合物的合成、表征和热分析

African Journal of Pure and Applied Chemistry Pub Date : 2014-10-31 DOI: 10.5897/AJPAC2014.0592

S. Chandraleka, G. Chandramohan

{"title":"Synthesis, characterization and thermal analysis of the copper(II) complexes with 2,2-bipyridyl and 1,10-phenanthroline","authors":"S. Chandraleka, G. Chandramohan","doi":"10.5897/AJPAC2014.0592","DOIUrl":"https://doi.org/10.5897/AJPAC2014.0592","url":null,"abstract":"The Cu(II) complexes were synthesized by the addition of Cu(II) acetate monohydrate to ligand in aqueous solution with 1,10-phenanthroline and 2,2'-bipyridyl which led to the precipitation of complexes. The synthesized Cu(II) complexes [Cu(SAla)phen(H2O)].H2O, [Cu(SAla)bpy(H2O)].H2O were found to be soluble in water, ethanol, methanol and DMSO. The electronic spectra and the magnetic moment support the stereochemistry of the complexes. The electronic spectra of all the complexes display a broad band with maximum at 14765 to 15503 cm -1 , which suggested an octahedral geometry of the metal ion. The magnetic moment at the room temperature lying in the range of 1.78 to 2.09 BM corresponds to one unpaired electron which are slightly greater than the spin only value of 1.73 BM, which was expected for one unpaired electron which offer possibility of the paramagnetic nature. The electronic spectra of free ligand shows band at 35651 cm -1 which are intra ligand charge transfer band (INCT). The electronic absorption spectra of the schiff base complexes were recorded using DMSO solvent. The spectrum of Cu(II) complexes display a broad band at 14765 cm -1 , which attributed to 2 Eg 2 T2g transition, which strongly favours the octahedral geometry around the central metal ion. The thermal gravimetric analysis (TGA), derivative thermogravimetric analysis (DTG), differential thermal analysis (DTA) experiments were carried out to explore the thermal stability of the complexes. The thermal behaviours of all the metal complexes were studied in the temperature range of 0 to 1400°C. The TGA, DTG and DTA studies of complexes reveal that the decomposition proceeds in three steps.","PeriodicalId":7556,"journal":{"name":"African Journal of Pure and Applied Chemistry","volume":"1992 1","pages":"162-175"},"PeriodicalIF":0.0,"publicationDate":"2014-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90389591","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: 16

Kinetic and equilibrium studies of the heavy metal remediation potential of Helix pomentia 螺旋体重金属修复潜力的动力学与平衡研究

African Journal of Pure and Applied Chemistry Pub Date : 2014-09-19 DOI: 10.5897/AJPAC2014.

M. D. Adeoye, L. Azeez, Abdulazeez T. Lawal, O. Olayiwola, Olanrewaju Razaq Shitta

{"title":"Kinetic and equilibrium studies of the heavy metal remediation potential of Helix pomentia","authors":"M. D. Adeoye, L. Azeez, Abdulazeez T. Lawal, O. Olayiwola, Olanrewaju Razaq Shitta","doi":"10.5897/AJPAC2014.","DOIUrl":"https://doi.org/10.5897/AJPAC2014.","url":null,"abstract":"Heavy metals are one of the major pollutants in water and are very toxic. However, chitosan – a waste biomass of agricultural products possess the ability to chelate heavy metals in water. In this study, the application of snail (Helix pomatia) shell based chitosan for remediating heavy metals contaminated Osun River (OSR), Odo-ebu stream (OBS) and Aso well water (AWW), all in Osogbo community, Nigeria; and the binding efficiency of chitosan for heavy metals in these water sources were evaluated. The result shows the prevalence of Iron (Fe), Cadmium (Cd), Zinc (Zn), Copper (Cu), Chromium (Cr), and Lead (Pb) ions in the three water samples with OBS and OSR having higher metal concentrations in the order: Pb > Cd > Fe > Zn > Cr > Cu compared with AWW which follows the order: Fe > Zn > Pb > Cr > Cd > Cu. The concentration range of heavy metals in OBS and OSR were (0.0011 -2.831) mg/L and (0.0012 -1.687) mg/L respectively, while for AWW it was (0.0004-0.0237) mg/L and below the Standard Organization of Nigeria (SON) 2007 and World Health Organization (WHO) 2004; maximum permissible level of metal ions in drinking water. The prepared chitosan is a selective candidate for remediating four heavy metals ions from these water samples, with the maximum sorption capacities for the metal ions in the sequence: Pb > Cd > Fe > Cr. The sorption behaviour followed a pseudo-second-order model, while the equilibrium data correlated well with the Langmuir isotherm models with the RL values in the range 0 < RL < 1. \u0000 Key words: Heavy metals, Helix pomatia, chitosan, dumpsite, equilibrium studies.","PeriodicalId":7556,"journal":{"name":"African Journal of Pure and Applied Chemistry","volume":"28 1","pages":"123-133"},"PeriodicalIF":0.0,"publicationDate":"2014-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91200181","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

Synthesis, spectroscopy and electrochemistry of 2-(mercapto/hydroxyl)pyridine-bis-{1-(alkyl)-2-(arylazo) imidazole}ruthenium(II) 2-(巯基/羟基)吡啶-双-{1-(烷基)-2-(芳偶氮)咪唑}钌(II)的合成、光谱学和电化学

African Journal of Pure and Applied Chemistry Pub Date : 2014-08-31 DOI: 10.5897/AJPAC2014.0586

Byabartta Prithwiraj

引用次数: 0

Solvent effect and catalysis in the synthesis of thiosemicarbazone derivatives from ketones and 4-phenylthiosemicarbazide 酮类和4-苯基硫代氨基脲合成硫代氨基脲衍生物的溶剂效应及催化作用

African Journal of Pure and Applied Chemistry Pub Date : 2014-08-31 DOI: 10.5897/AJPAC2014.0575

Urbain C. Kass ehin, F. Gbaguidi, C. N. Kapanda, C. McCurdy, J. Poupaert

{"title":"Solvent effect and catalysis in the synthesis of thiosemicarbazone derivatives from ketones and 4-phenylthiosemicarbazide","authors":"Urbain C. Kass ehin, F. Gbaguidi, C. N. Kapanda, C. McCurdy, J. Poupaert","doi":"10.5897/AJPAC2014.0575","DOIUrl":"https://doi.org/10.5897/AJPAC2014.0575","url":null,"abstract":"In this paper, we performed a series of experiments aiming at establishing the solvent effects in the condensation of 4-phenylthiosemicarbazide with 4-nitroacetophenone to form the expected thiosemicarbazone derivative, reaction which was chosen as pilot reaction, having in mind to set up optimal reaction conditions for the future elaboration of a compound library of thiosemicarbazone derivatives. Methanol was found to be a suitable solvent for this purpose. As a general rule, acid catalysis was found to perform better than base catalysis. General acid-base catalysis performed also in a quite satisfactory manner and in this connection, among the catalytic systems, anilinium chloride performed optimally allowing the reaction to go to completion at room temperature in excellent yield within 24 h at room temperature. A series of six bench mark molecules of increasing steric effect were synthesized in fair to good yields using this method. \u0000 \u0000 \u0000 \u0000 Key words: Thiosemicarbazone, thiosemicarbazide, solvent effect, acid-base catalysis, alpha-effect, nucleophilic catalysis, anilinium catalysis.","PeriodicalId":7556,"journal":{"name":"African Journal of Pure and Applied Chemistry","volume":"693 1","pages":"110-115"},"PeriodicalIF":0.0,"publicationDate":"2014-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81451203","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

Prediction of substituent types and positions on skeleton of eudesmane-type sesquiterpenes using generalized regression neural network (GRNN) 应用广义回归神经网络(GRNN)预测桂烷型倍半萜骨架上取代基类型和位置

African Journal of Pure and Applied Chemistry Pub Date : 2014-07-31 DOI: 10.5897/AJPAC2014.0569

T. Alawode, K. Alawode

{"title":"Prediction of substituent types and positions on skeleton of eudesmane-type sesquiterpenes using generalized regression neural network (GRNN)","authors":"T. Alawode, K. Alawode","doi":"10.5897/AJPAC2014.0569","DOIUrl":"https://doi.org/10.5897/AJPAC2014.0569","url":null,"abstract":"Sesquiterpenes are formed from countless biogenetic pathways and are therefore a constant challenge to spectroscopists in structure elucidation. In this study, we explore the ability of generalized regression neural network (GRNN), an architecture of artificial neural networks (ANNs), to predict the substituent types on eudesmanes, one of the most representative skeletons of sesquiterpenes. Carbon-13 (13C) nuclear magnetic resonance (NMR) chemical shift values of skeletons of 291 eudesmane sesquiterpenes were used as the input data used for the network. Each substituent type on the skeleton of the different compounds were coded and used as the output data for the network. These data were used to train the network. After training, the network was simulated using 34 test compounds. The results showed that the GRNN had between 73.33 to 100% recognition rates of the test compounds. GRNN could therefore be a powerful aid in the structural elucidation of organic compounds. \u0000 \u0000 \u0000 \u0000 Key words: Artificial neural networks (ANNs), generalized regression neural network (GRNN), eudesmane skeleton, sesquiterpenes, structural elucidation.","PeriodicalId":7556,"journal":{"name":"African Journal of Pure and Applied Chemistry","volume":"1 1","pages":"102-109"},"PeriodicalIF":0.0,"publicationDate":"2014-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76981141","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: 3

Dichloro-diphenyl-trichloroethane (DDT) residue levels in marketed Silver Fish (Rastreneobola argentea) caught from major water bodies in Uganda 从乌干达主要水体捕获的市售银鱼(拉斯特尼博拉银鱼)中滴滴涕的残留水平

African Journal of Pure and Applied Chemistry Pub Date : 2014-06-30 DOI: 10.5897/AJPAC2014.0576

Proscovia Nnamuyomba, J. Mbabazi, M. Ntale

引用次数: 1

Colour of starch-iodine complex as index of retrogradability of starch pastes 淀粉-碘络合物的颜色作为淀粉糊可逆行性的指标

African Journal of Pure and Applied Chemistry Pub Date : 2014-05-31 DOI: 10.5897/AJPAC2014.0571

M. Louis, B. Gabriel

{"title":"Colour of starch-iodine complex as index of retrogradability of starch pastes","authors":"M. Louis, B. Gabriel","doi":"10.5897/AJPAC2014.0571","DOIUrl":"https://doi.org/10.5897/AJPAC2014.0571","url":null,"abstract":"Starch retrogradation is mainly due to the amylose fraction of starch. Amylose quantification is usually done by iodine staining with which it forms a blue colour complex while starch retrogradability can be monitored by freeze-thaw stability measurements. In this work, spectroscopic determination of the blue value and visual monitoring of starch–iodine colour complex were used to study starch retrogradation. The results obtained were compared with that from freeze-thaw stability measurements. Native cassava starch, its carboxymethylated and cyanoethylated derivatives of different degrees of substitution (D.S) were used in the study. From the results, increase in starch derivatization reduced amylose ability to bind iodine, decreased the blue value with resultant decay in the blue colour of the starch-iodine complex. The blue black colour of the starch-iodine complex was lost in carboxymethyl starch at D.S of 0.145 and cyanoethyl starch at D.S of 0.141; at these degrees of substitution, the helical structure of amylose was no longer maintained by the starch molecules and retrogradation eliminated. Freeze-thaw stability study showed clear pastes with no evidence of retrogradation over 10 freeze-thaw cycles for derivatized starches above these degrees of substitutions. This showed a good agreement with that obtained from the colour of the starch-iodine complex. Hence derivatized starch products, which showed absence of blue black colour of starch-iodine complex would be freeze-thaw stable over a long period of cold storage. The disappearance of the blue colour of starch-iodine complex thus becomes an index of retrogradability and freeze-thaw stability of starch pastes on cold storage.","PeriodicalId":7556,"journal":{"name":"African Journal of Pure and Applied Chemistry","volume":"12 1","pages":"89-93"},"PeriodicalIF":0.0,"publicationDate":"2014-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87539212","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: 13

Phytochemical screening of the leaf extracts of Hyptis spicigera plant 棘球蜂叶提取物的植物化学筛选

African Journal of Pure and Applied Chemistry Pub Date : 2014-05-31 DOI: 10.5897/AJPAC2014.0560

Z. Ladan, E. Temple

{"title":"Phytochemical screening of the leaf extracts of Hyptis spicigera plant","authors":"Z. Ladan, E. Temple","doi":"10.5897/AJPAC2014.0560","DOIUrl":"https://doi.org/10.5897/AJPAC2014.0560","url":null,"abstract":"The present study reports the screening of phytochemical constituents of the leaf extracts of Hyptis spicigera using hexane, ethylacetate and methanol and the leaf powder of the plant. Qualitative analysis of phytochemical constituents showed the presence of the following secondary metabolites vitannins, carbohydrates, saponins, flavonoids, steroids, alkaloids, quinones, coumarin, terpenoids, resins and cardiac glycosides. The quantitative analysis of total phenolics, alkaloids, saponins, terpenoids and flavonoids carried out using standard protocols revealed the presence of flavonoids (8.82%), saponins (6.23%), terpenoids (16.10%), alkaloids (7.55%) and phenolics (20.75%) respectively. Phenolics showed the highest content (20.75%) while saponins (6.23%) gave the least content. The high content of phenolics in the plant showed that H. spicigera plant may contain antioxidant properties and could be a good source of natural antioxidants. Also, the richness in flavonoids, saponins, alkaloids and terpenoids in this plant can be correlated with its medicinal properties used by traditional herbal healers in Northern Nigeria. \u0000 \u0000 Key words: Hyptis spicigera, phytochemical screening, secondary metabolites.","PeriodicalId":7556,"journal":{"name":"African Journal of Pure and Applied Chemistry","volume":"68 1","pages":"83-88"},"PeriodicalIF":0.0,"publicationDate":"2014-05-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84217071","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: 22

Determination of some heavy metals in selected edible vegetables grown along River Yedzaram in Uba area Adamawa State, Nigeria 尼日利亚阿达马瓦州乌巴地区Yedzaram河沿岸种植的选定食用蔬菜中重金属的测定

African Journal of Pure and Applied Chemistry Pub Date : 2014-04-30 DOI: 10.5897/AJPAC2014.0564

P. Alexander, W. H. Ubandoma

{"title":"Determination of some heavy metals in selected edible vegetables grown along River Yedzaram in Uba area Adamawa State, Nigeria","authors":"P. Alexander, W. H. Ubandoma","doi":"10.5897/AJPAC2014.0564","DOIUrl":"https://doi.org/10.5897/AJPAC2014.0564","url":null,"abstract":"The levels of some heavy metals were investigated in selected edible potions of the vegetables; Amarathus caudatus (Spinach) and Hibiscus sabdariffa (Rosella) are grown in Uba area along the Yedzaram River in North Eastern Adamawa State, Nigeria. All samples were randomly collected from two different gardens. The levels of the heavy metals, (Cu, Fe, Cd, Cr and Zn) were analyzed using Atomic Absorption Spectrophotometer (AAS) (BUK 210 model). In all the samples analyzed, Cd and Cr were not detected. The levels of heavy metals in Farm A for H. sabdariffa leaves ranges from Cu (30.00 ± 0.15 mg/kg to 31.00 ± 0.18 mg/kg), Fe (37.39 ± 0.02 mg/kg to 48.47 ± 0.10 mg/kg), Zn (13.00 ± 0.01 mg/kg to 25.50 ± 0.48 mg/kg), respectively. In Spinach, the results ranged from Cu (34.33 ± 0.42 mg/kg to 34.50 ± 0.05 mg/kg), Fe (31.72 ± 0.71 mg/kg to 43.33 ± 0.02 mg/kg), Zn (21.17 ± 0.14 mg/kg to 10.83 ± 0.17 mg/kg), respectively. The data were analyzed with t-test and analysis of variance (ANOVA). There were significant differences (p Cu > Zn in Farm A and Cu> Fe> Zn in Farm B. The elevated levels of metals in vegetables in the two gardens could be attributed to excessive usage of fertilizers and other agro - chemicals and of course the environmental factors of the areas. The results were however lower than the published threshold values considered toxic for mature plant tissue, except Fe which has higher values. The consumption of these vegetables as food may not pose possible health hazards to human at the time of the study. \u0000 \u0000 Key words: Heavy metals, Amarathus caudatus, Hibiscus sabdariffa, Uba area, fertilizers.","PeriodicalId":7556,"journal":{"name":"African Journal of Pure and Applied Chemistry","volume":"39 1","pages":"78-82"},"PeriodicalIF":0.0,"publicationDate":"2014-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80211511","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: 8

1-Indanone chalcones and their 2,4-Dinitrophenylhydrazone derivatives: Synthesis, physicochemical properties and in vitro antibacterial activity 1-吲哚酮查尔酮及其2,4-二硝基苯腙衍生物:合成、理化性质及体外抗菌活性

African Journal of Pure and Applied Chemistry Pub Date : 2014-04-30 DOI: 10.5897/AJPAC2014.0558

O. A. Fadare, D. Akinpelu, Henry Ejemubu, C. A. Obafemi

{"title":"1-Indanone chalcones and their 2,4-Dinitrophenylhydrazone derivatives: Synthesis, physicochemical properties and in vitro antibacterial activity","authors":"O. A. Fadare, D. Akinpelu, Henry Ejemubu, C. A. Obafemi","doi":"10.5897/AJPAC2014.0558","DOIUrl":"https://doi.org/10.5897/AJPAC2014.0558","url":null,"abstract":"Chalcones are natural biocides. Several publications appear every year covering the synthesis of chalcones because they exhibit an array of pharmacological activities. In this study, some condensation reactions of 1-Indanone with substituted benzaldehydes were carried out under different reaction conditions. The chalcone products were converted to their corresponding 2,4-Dinitrophenylhydrazone derivatives and evaluated against five gram-positive and eight gram-negative bacteria for their in vitro antibacterial property. Antimicrobial activity was observed against many of the tested strains, with zones of inhibition ranging from 10 to 28 mm. In many cases, the hydrazone derivatives were more active than their chalcone precursors. The best results were obtained against gram-negative bacteria for most of the compounds. Compound 1b was the most active with its minimum inhibitory concentrations (MICs) against six strains of bacteria ranging from 15.6 to 31.3 µg/ml, hence, could be developed as an antibacterial agent against infections caused by some gram-negative bacteria such as Pseudomonas aeruginosa and Salmonella typhimurium. \u0000 \u0000 Key words: Antibacterial activity, chalcones, 2,4-Dinitrophenylhydrazones, 1-Indanone, microwave-assisted synthesis, minimum inhibitory concentration.","PeriodicalId":7556,"journal":{"name":"African Journal of Pure and Applied Chemistry","volume":"66 1","pages":"68-77"},"PeriodicalIF":0.0,"publicationDate":"2014-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88965993","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: 10