Pub Date : 2019-11-21DOI: 10.11648/j.sjc.20190705.12
M. Nasir, M. A. Ahmad, S. Hussain, M. Ismaeel
The current studies reveal the effect of a plant growth regulator (PGRs) on growth and yield performance of wheat crop. It was demonstrated that plant morphology, physiology, biochemistry and yield of wheat crop is highly effected/ stimulated by the use of low/ different concentration of growth regulators. Various filed experiments were conducted to investigate the effect of concentrations and formulations of three PGR salts (ortho-nitrophenolate, para-nitrophenolate and Sodium-5-Nitroguaiacolate). Various compositions of PGRs were applied as foliar application during different stages of plant growth. Control measurements were also carried out simultaneously using water only. A significant increase in plant height, stem growth, leaf development, chlorophyll contents and other biochemical contents of plant has been observed by the use of PGR. The results indicate that the PGR concentrations of 100 ppm and 150 ppm were found to give the best results. From the current study, it was suggested that dose concentration ranging from100ppm to 150ppm has momentous potential on plant growth and yield of wheat crop. Also it enhances the nutritional value of crop and reduces the economic cost of former.
{"title":"Significance of Plant Growth Regulators (PGR’s) on the Growth and Yield of Wheat Crop","authors":"M. Nasir, M. A. Ahmad, S. Hussain, M. Ismaeel","doi":"10.11648/j.sjc.20190705.12","DOIUrl":"https://doi.org/10.11648/j.sjc.20190705.12","url":null,"abstract":"The current studies reveal the effect of a plant growth regulator (PGRs) on growth and yield performance of wheat crop. It was demonstrated that plant morphology, physiology, biochemistry and yield of wheat crop is highly effected/ stimulated by the use of low/ different concentration of growth regulators. Various filed experiments were conducted to investigate the effect of concentrations and formulations of three PGR salts (ortho-nitrophenolate, para-nitrophenolate and Sodium-5-Nitroguaiacolate). Various compositions of PGRs were applied as foliar application during different stages of plant growth. Control measurements were also carried out simultaneously using water only. A significant increase in plant height, stem growth, leaf development, chlorophyll contents and other biochemical contents of plant has been observed by the use of PGR. The results indicate that the PGR concentrations of 100 ppm and 150 ppm were found to give the best results. From the current study, it was suggested that dose concentration ranging from100ppm to 150ppm has momentous potential on plant growth and yield of wheat crop. Also it enhances the nutritional value of crop and reduces the economic cost of former.","PeriodicalId":21607,"journal":{"name":"Science Journal of Chemistry","volume":"18 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73590000","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}
Pub Date : 2019-10-24DOI: 10.11648/J.SJC.20190705.11
Huma Bhatti, Q. Zaheer, Yildiz Tehseen, Zahid Shaiq, K. M. Khan, A. Hameed, J. Iqbal
Role of aldose reductase (ALR2) in diabetic complications such as retinopathy, nephropathy, neuropathy, and cataract etc. is well-evident. ALR2 in the first step of polyol pathway reduces glucose to sorbitol whose elevated level leads to diabetic cataract, characterize by clouding of the lens in the eye that affects vision. Inhibition of ALR2 enzyme with small molecules as inhibitor is a rapid approach for diabetic management. In the present study the synthetic route to synthesize desired benzopyrazines and a library of sixteen (16) methyl benzopyrazines were screened against aldose reductase. From the bioactivity results, the 3'-hydroxyphenyl benzopyrazine 6l was found most active (IC50 = 1.34 ± 0.07 µM) while 3'-bromophenyl analogue 6i showed comparable activity for ALR2 (IC50 = 3.48 ± 0.66 µM) as compared to standard sorbinil (IC50 = 3.14 ± 0.02 µM). Both compounds (6l and 6i) showed excellent selectivity for ALR2 over aldehyde reductase (ALR1) which has important role in detoxification of toxic aldehydes. The structure of two regio-isomers were fully characterize by 1H and 13C NMR two dimensional NMR techniques including COSY, NOESY, HSQC, and HMBC. Regio-isomers separation was proved to be difficult in different solvent systems. Only an isomer of 3'-bromo benzopyrazine 6i' was isolated that help to assign the structure of regioisomers from NMR data. All the benzopyrazines were fully characterized by using different spectral techniques including 1H, 13C NMR, IR spectroscopy, and mass spectrometry.
{"title":"Benzopyrazines: Synthesis, Characterization and Evaluation as Aldose Reductase Inhibitors","authors":"Huma Bhatti, Q. Zaheer, Yildiz Tehseen, Zahid Shaiq, K. M. Khan, A. Hameed, J. Iqbal","doi":"10.11648/J.SJC.20190705.11","DOIUrl":"https://doi.org/10.11648/J.SJC.20190705.11","url":null,"abstract":"Role of aldose reductase (ALR2) in diabetic complications such as retinopathy, nephropathy, neuropathy, and cataract etc. is well-evident. ALR2 in the first step of polyol pathway reduces glucose to sorbitol whose elevated level leads to diabetic cataract, characterize by clouding of the lens in the eye that affects vision. Inhibition of ALR2 enzyme with small molecules as inhibitor is a rapid approach for diabetic management. In the present study the synthetic route to synthesize desired benzopyrazines and a library of sixteen (16) methyl benzopyrazines were screened against aldose reductase. From the bioactivity results, the 3'-hydroxyphenyl benzopyrazine 6l was found most active (IC50 = 1.34 ± 0.07 µM) while 3'-bromophenyl analogue 6i showed comparable activity for ALR2 (IC50 = 3.48 ± 0.66 µM) as compared to standard sorbinil (IC50 = 3.14 ± 0.02 µM). Both compounds (6l and 6i) showed excellent selectivity for ALR2 over aldehyde reductase (ALR1) which has important role in detoxification of toxic aldehydes. The structure of two regio-isomers were fully characterize by 1H and 13C NMR two dimensional NMR techniques including COSY, NOESY, HSQC, and HMBC. Regio-isomers separation was proved to be difficult in different solvent systems. Only an isomer of 3'-bromo benzopyrazine 6i' was isolated that help to assign the structure of regioisomers from NMR data. All the benzopyrazines were fully characterized by using different spectral techniques including 1H, 13C NMR, IR spectroscopy, and mass spectrometry.","PeriodicalId":21607,"journal":{"name":"Science Journal of Chemistry","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79279519","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}
Pub Date : 2019-10-24DOI: 10.11648/j.sjc.20190704.12
Jules Yoda, S. Ouedraogo, A. Saba
Natural or synthetic coumarins are of great interest, since many of them show prominent biological activity and photochemical characteristics. In particular, hydroxycoumarins and their derivatives have been extensively studied in various fields such as biology, medicine, physics and chemistry. Among the well-known compounds is 7-hydroxycoumarin, also known as umbelliferone and 4-hydroxycoumarin. Against 3-hydroxycoumarin and its derivatives are less known and studied. In this study, new acyl derivatives were synthesized from 3-hydroxycoumarin or chromen-2,3-dione its tautomeric form and chloride acid in the presence of an appropriated base. The structures of the newly obtained compounds were confirmed by elemental analysis, mass spectrometry (MS), IR and NMR spectrometry and X-ray diffractometry. In addition, the fluorescence properties of the titre compounds were also studied in both liquid and solid state. In liquid media, the study concerned their behaviour in fluorescence emission spectrometry in 6 solvents of different polarities. The new heterocyclic compounds have been successfully synthesized. Fluorescence spectrum analyses show that these compounds are all fluorescent in both solid and liquid state with varying fluorescence intensities (IF). On solvatochromic analyses, it appears that the behaviour of the spectrum depends strongly on the solvent. The fluorescence intensity and wavelength (λem) vary depending on the nature of the substituent (R) and especially that of the solvent. It should also be noted that chloroform is the solvent that most enhances the fluorescence of the compounds.
{"title":"2-oxo-2H-chromen-3-yl Propionate and 2-oxo-2H-chromen-3-yl Acetate: Short-step Synthesis, Characterization and Fluorescence Properties","authors":"Jules Yoda, S. Ouedraogo, A. Saba","doi":"10.11648/j.sjc.20190704.12","DOIUrl":"https://doi.org/10.11648/j.sjc.20190704.12","url":null,"abstract":"Natural or synthetic coumarins are of great interest, since many of them show prominent biological activity and photochemical characteristics. In particular, hydroxycoumarins and their derivatives have been extensively studied in various fields such as biology, medicine, physics and chemistry. Among the well-known compounds is 7-hydroxycoumarin, also known as umbelliferone and 4-hydroxycoumarin. Against 3-hydroxycoumarin and its derivatives are less known and studied. In this study, new acyl derivatives were synthesized from 3-hydroxycoumarin or chromen-2,3-dione its tautomeric form and chloride acid in the presence of an appropriated base. The structures of the newly obtained compounds were confirmed by elemental analysis, mass spectrometry (MS), IR and NMR spectrometry and X-ray diffractometry. In addition, the fluorescence properties of the titre compounds were also studied in both liquid and solid state. In liquid media, the study concerned their behaviour in fluorescence emission spectrometry in 6 solvents of different polarities. The new heterocyclic compounds have been successfully synthesized. Fluorescence spectrum analyses show that these compounds are all fluorescent in both solid and liquid state with varying fluorescence intensities (IF). On solvatochromic analyses, it appears that the behaviour of the spectrum depends strongly on the solvent. The fluorescence intensity and wavelength (λem) vary depending on the nature of the substituent (R) and especially that of the solvent. It should also be noted that chloroform is the solvent that most enhances the fluorescence of the compounds.","PeriodicalId":21607,"journal":{"name":"Science Journal of Chemistry","volume":"27 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82740417","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}
Pub Date : 2019-10-18DOI: 10.11648/j.sjc.20190704.11
Mao Jia, Feng Yizhi, Qi Xiaoxue, Han Jifeng, Pan Jinju, Liang Lin, Liu Wei, Zuo Bojun
A rapid and sensitive analytical method for the determination of isoxaflutole and diketonitrile (DKN) residues in maize was established based on QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) and high performance liquid chromatography with tandem mass spectrometry (HPLC-MS/MS). The samples were extracted with acetonitrile and purified with octadecylsilane (C18). The mass spectrometer was performed in multi-reaction monitoring mode, and electrospray ionization in negative mode was selected. The isoxaflutole and DKN residues were quantified by the external standard method using the matched standard solution to compensate for matrix effect. The results indicated that the calibration curves of isoxaflutole and DKN were linear in the range of 0.005-0.5mg/L with correlation coefficients of more than 0.9922. When the addition level ranged from 0.01 to 0.1mg/kg the average recoveries of isoxaflutole and DKN in maize, green maize and straw were 95%-108%, and the relative standard deviation (RSD) ranged from 2% to 11%. The limit of quantitation (LOQ) were 0.01 mg/kg in different matrices. This method has many characteristics, such as simple, rapid and accurate, and can be adapted for the confirmation of isoxaflutole and DKN residues in maize samples.
{"title":"Method for Residues Analysis of Isoxaflutole and Its Metabolites in Maize","authors":"Mao Jia, Feng Yizhi, Qi Xiaoxue, Han Jifeng, Pan Jinju, Liang Lin, Liu Wei, Zuo Bojun","doi":"10.11648/j.sjc.20190704.11","DOIUrl":"https://doi.org/10.11648/j.sjc.20190704.11","url":null,"abstract":"A rapid and sensitive analytical method for the determination of isoxaflutole and diketonitrile (DKN) residues in maize was established based on QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) and high performance liquid chromatography with tandem mass spectrometry (HPLC-MS/MS). The samples were extracted with acetonitrile and purified with octadecylsilane (C18). The mass spectrometer was performed in multi-reaction monitoring mode, and electrospray ionization in negative mode was selected. The isoxaflutole and DKN residues were quantified by the external standard method using the matched standard solution to compensate for matrix effect. The results indicated that the calibration curves of isoxaflutole and DKN were linear in the range of 0.005-0.5mg/L with correlation coefficients of more than 0.9922. When the addition level ranged from 0.01 to 0.1mg/kg the average recoveries of isoxaflutole and DKN in maize, green maize and straw were 95%-108%, and the relative standard deviation (RSD) ranged from 2% to 11%. The limit of quantitation (LOQ) were 0.01 mg/kg in different matrices. This method has many characteristics, such as simple, rapid and accurate, and can be adapted for the confirmation of isoxaflutole and DKN residues in maize samples.","PeriodicalId":21607,"journal":{"name":"Science Journal of Chemistry","volume":"12 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75422462","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}
Pub Date : 2019-07-01DOI: 10.11648/J.SJC.20190702.13
Q. Nguyen, Quang Hai Lam, Phuong Thuy Pham Thi, Van Tuyen Nguyen
A series of platinum (II) complexes of Schiff bases derived from various salicylaldehydes with ethylenediamine were synthesized and characterized by ESI-MS, NMR and IR. The results of ESI-MS and NMR spectra data showed that the separation of hydrogen from hydoxy group and different chemical shifts of typical bondings between ligands and platinum (II) complexes evidenced for coordination of Pt (II) and tetradentate ligands. The IR spectral studies indicated the binding sites of the salen ligands with Pt (II). Their photophysical properties studied by UV-vis and luminescent spectroscopies performed the photoactivity of investigated platinum (II) complexes. The obvious effect of electron-withdrawing and – donoring substituted groups at the same position of salicyl rings and the impact of methoxy at different position of salicyl rings to their photophysical properties were studied and compared to complex 1 without substituted group. The obtained complexes were screened for their in vitro antitumour activities against KB and MCF-7 human cancer cell lines. Complex 4 showed the best bioactivity for both KB and MCF-7 human cancer cells with IC50 1.92 µM.
{"title":"Synthesis, Characterization and In Vitro Cytotoxicity of Platinum (II) Complexes with Some Tetradentate Salen Ligands","authors":"Q. Nguyen, Quang Hai Lam, Phuong Thuy Pham Thi, Van Tuyen Nguyen","doi":"10.11648/J.SJC.20190702.13","DOIUrl":"https://doi.org/10.11648/J.SJC.20190702.13","url":null,"abstract":"A series of platinum (II) complexes of Schiff bases derived from various salicylaldehydes with ethylenediamine were synthesized and characterized by ESI-MS, NMR and IR. The results of ESI-MS and NMR spectra data showed that the separation of hydrogen from hydoxy group and different chemical shifts of typical bondings between ligands and platinum (II) complexes evidenced for coordination of Pt (II) and tetradentate ligands. The IR spectral studies indicated the binding sites of the salen ligands with Pt (II). Their photophysical properties studied by UV-vis and luminescent spectroscopies performed the photoactivity of investigated platinum (II) complexes. The obvious effect of electron-withdrawing and – donoring substituted groups at the same position of salicyl rings and the impact of methoxy at different position of salicyl rings to their photophysical properties were studied and compared to complex 1 without substituted group. The obtained complexes were screened for their in vitro antitumour activities against KB and MCF-7 human cancer cell lines. Complex 4 showed the best bioactivity for both KB and MCF-7 human cancer cells with IC50 1.92 µM.","PeriodicalId":21607,"journal":{"name":"Science Journal of Chemistry","volume":"25 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74220960","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}
Pub Date : 2019-06-29DOI: 10.11648/J.SJC.20190702.12
Prabha Ranasinghe, Christopher I. Olivares, W. Champion, Cindy M Lee
2,2’,3,5’,6-Pentachlorobiphenyl (PCB-95) is an environmentally significant chiral PCB, of which enantioselective toxicity, biodegradation and chiral stability studies have been limited to date, as no commercially available enantiomers exist for PCB-95 and due to the lack of an efficient preparatory chiral separation method. A selective, sensitive, and rapid high-performance liquid chromatography with UV detection (HPLC-UV) method has been developed and validated for the chromatographic separation and quantitation of PCB-95 enantiomers. In this study, we resolved enantiomers of PCB-95 using a cellulose tris (4-methylbenzoate) Chiralcel OJ- H column. After evaluating mobile phase compositions and temperatures, optimum separation and detection were obtained with isocratic 100% n-hexane as the mobile phase, a column temperature of 20°C, a flow rate of 1 mL/min, and a detection wavelength of 280 nm. The total run time was 8 minutes. Enantiomer purity was confirmed using enantioselective gas capillary chromatography-electron capture detection. The developed method was validated as per International Conference on Harmonization (ICH) guidelines with respect to limit of detection, limit of quantification, precision, linearity, robustness and ruggedness.
{"title":"Atropisomeric Separation of PCB-95 by HPLC","authors":"Prabha Ranasinghe, Christopher I. Olivares, W. Champion, Cindy M Lee","doi":"10.11648/J.SJC.20190702.12","DOIUrl":"https://doi.org/10.11648/J.SJC.20190702.12","url":null,"abstract":"2,2’,3,5’,6-Pentachlorobiphenyl (PCB-95) is an environmentally significant chiral PCB, of which enantioselective toxicity, biodegradation and chiral stability studies have been limited to date, as no commercially available enantiomers exist for PCB-95 and due to the lack of an efficient preparatory chiral separation method. A selective, sensitive, and rapid high-performance liquid chromatography with UV detection (HPLC-UV) method has been developed and validated for the chromatographic separation and quantitation of PCB-95 enantiomers. In this study, we resolved enantiomers of PCB-95 using a cellulose tris (4-methylbenzoate) Chiralcel OJ- H column. After evaluating mobile phase compositions and temperatures, optimum separation and detection were obtained with isocratic 100% n-hexane as the mobile phase, a column temperature of 20°C, a flow rate of 1 mL/min, and a detection wavelength of 280 nm. The total run time was 8 minutes. Enantiomer purity was confirmed using enantioselective gas capillary chromatography-electron capture detection. The developed method was validated as per International Conference on Harmonization (ICH) guidelines with respect to limit of detection, limit of quantification, precision, linearity, robustness and ruggedness.","PeriodicalId":21607,"journal":{"name":"Science Journal of Chemistry","volume":"41 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-06-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72977521","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}
Pub Date : 2019-06-19DOI: 10.11648/J.SJC.20190702.11
A. Kassahun, G. Feleke
Eucalyptus globulus grows well in different parts of the world. More than 300 species of this genus have been shown to contain volatile oil. Essential oil contains many hundred chemical elements and this advanced mixture of compounds offers the oil its characteristic fragrance and flavor. The investigation has been carried out to know the chemical composition, Physico-Chemical properties of essential oils and Eucalyptus globulus leave grown at Ankober woreda, Ethiopia. To extract the essential oil, the fresh leaves of Eucalyptus globulus were subjected to hydro distillation for 3 hours using a Clevenger-type apparatus and the percent yield was 2.1%. Physico-chemical properties such as refractive index (1.451), relative density (0.925), optical rotation (+8o), Solubility, color and odour were determined. Physico-chemical analysis of Eucalyptus globulus leaves such as total ash, water soluble ash; acid insoluble ash, moisture content and pH were found to be (6.09), (2.18), (2.22), (35.32) and (5.43) respectively. The composition of essential oils of Eucalyptus globulus were analyzed using Gas Chromatography-Mass Spectroscopy (GC-MS). A total of twenty volatile components were identified in this work. The main components of the essential oils are Alpha-Pinene (25.55%), D-Limonene (5.687%) and Eucalyptol (55.43%).
{"title":"Chemical Composition and Physico-Chemical Analysis of Eucalyptus Globulus Leave and Oil","authors":"A. Kassahun, G. Feleke","doi":"10.11648/J.SJC.20190702.11","DOIUrl":"https://doi.org/10.11648/J.SJC.20190702.11","url":null,"abstract":"Eucalyptus globulus grows well in different parts of the world. More than 300 species of this genus have been shown to contain volatile oil. Essential oil contains many hundred chemical elements and this advanced mixture of compounds offers the oil its characteristic fragrance and flavor. The investigation has been carried out to know the chemical composition, Physico-Chemical properties of essential oils and Eucalyptus globulus leave grown at Ankober woreda, Ethiopia. To extract the essential oil, the fresh leaves of Eucalyptus globulus were subjected to hydro distillation for 3 hours using a Clevenger-type apparatus and the percent yield was 2.1%. Physico-chemical properties such as refractive index (1.451), relative density (0.925), optical rotation (+8o), Solubility, color and odour were determined. Physico-chemical analysis of Eucalyptus globulus leaves such as total ash, water soluble ash; acid insoluble ash, moisture content and pH were found to be (6.09), (2.18), (2.22), (35.32) and (5.43) respectively. The composition of essential oils of Eucalyptus globulus were analyzed using Gas Chromatography-Mass Spectroscopy (GC-MS). A total of twenty volatile components were identified in this work. The main components of the essential oils are Alpha-Pinene (25.55%), D-Limonene (5.687%) and Eucalyptol (55.43%).","PeriodicalId":21607,"journal":{"name":"Science Journal of Chemistry","volume":"114 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74833242","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}
Pub Date : 2019-05-17DOI: 10.11648/J.SJC.20190701.15
Melaku Masresha Woldamanuel
Heavy metal pollution is among the leading health concerns all over the world because of their long-term cumulative effects. khat (Catha edulisforsk), a plant used as a stimulant is grown in certain areas of East Africa and the Arab Peninsula this day it is a known cash crop in Ethiopia. Due to increased demand and value, many farmers have not only begun growing it but have also adopted modern farming methods which include application of fertilizers, pesticides, compost manure, and irrigation. Yet some of these agricultural practices such as application of fertilizers and pesticides are known to increase the concentration of heavy metals such as Cd, Pb, Zn and Cu in the soil. Some of these heavy metals such as Pband Cd are toxic even at low concentrations while Zn, Cu, Fe and Cr though essential in the body, are toxic at high levels This call for monitoring to make sure that the levels of heavy metals in khat do not exceed the threshold limits recommended by WHO due to their adverse health effects to man. This study therefore assesses selected chemical nutrients and toxic metal in khat that is available in Ethiopia. khat samples were collected from16 sits of the three main khat growing regions namely Oromiya, South Nation and Nationality and Amhara regional state Known weights of oven dried khat samples were digested using nitric andPerchloric acids. The digests were analyzed for selected heavy metals using flame atomic absorption spectrophotometer. The following concentration ranges in dry weight (μg/g) were obtained in khat: Zn (25.15-73.95), Cu (0.10-41.80), Cr (ND-39.50), Cd(ND-0.90) and Pb (0.50-13.00). Cd was only detected in khat samples from Oromiyaare more susceptible to adverse effects of Pb than adults. The results suggested that there was significant different (p 0.05) in the levels of heavy metals between khat from various regions. Levels of studied heavy metals in khat were below the maximum limits recommended by WHO except for Pb and Cr Therefore children should be discouraged from chewing khat since they are more susceptible to adverse effects of Pb than adults.
{"title":"Assessment of Selected Nutrients and Toxic Chemicals in Ethiopian Khat","authors":"Melaku Masresha Woldamanuel","doi":"10.11648/J.SJC.20190701.15","DOIUrl":"https://doi.org/10.11648/J.SJC.20190701.15","url":null,"abstract":"Heavy metal pollution is among the leading health concerns all over the world because of their long-term cumulative effects. khat (Catha edulisforsk), a plant used as a stimulant is grown in certain areas of East Africa and the Arab Peninsula this day it is a known cash crop in Ethiopia. Due to increased demand and value, many farmers have not only begun growing it but have also adopted modern farming methods which include application of fertilizers, pesticides, compost manure, and irrigation. Yet some of these agricultural practices such as application of fertilizers and pesticides are known to increase the concentration of heavy metals such as Cd, Pb, Zn and Cu in the soil. Some of these heavy metals such as Pband Cd are toxic even at low concentrations while Zn, Cu, Fe and Cr though essential in the body, are toxic at high levels This call for monitoring to make sure that the levels of heavy metals in khat do not exceed the threshold limits recommended by WHO due to their adverse health effects to man. This study therefore assesses selected chemical nutrients and toxic metal in khat that is available in Ethiopia. khat samples were collected from16 sits of the three main khat growing regions namely Oromiya, South Nation and Nationality and Amhara regional state Known weights of oven dried khat samples were digested using nitric andPerchloric acids. The digests were analyzed for selected heavy metals using flame atomic absorption spectrophotometer. The following concentration ranges in dry weight (μg/g) were obtained in khat: Zn (25.15-73.95), Cu (0.10-41.80), Cr (ND-39.50), Cd(ND-0.90) and Pb (0.50-13.00). Cd was only detected in khat samples from Oromiyaare more susceptible to adverse effects of Pb than adults. The results suggested that there was significant different (p 0.05) in the levels of heavy metals between khat from various regions. Levels of studied heavy metals in khat were below the maximum limits recommended by WHO except for Pb and Cr Therefore children should be discouraged from chewing khat since they are more susceptible to adverse effects of Pb than adults.","PeriodicalId":21607,"journal":{"name":"Science Journal of Chemistry","volume":"53 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86171470","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}
Pub Date : 2019-05-01DOI: 10.11648/J.SJC.20190703.11
A. Emadak, R. M. Nemba, Leonel Tsassi Djoumessi, Jules Cesar Epee Ndongue
A mathematical process of enumeration of Kekule structures of any polybenzenoid monoradical having only linear assemblies of benzenoid hydrocarbons is given by using a method which consisted of the excision of the radical center in order to obtain a conjugated hydrocarbon having a 12-annulene core ring appended to one or more polybenzenoid fragments, the partition of the resulting conjugated hydrocarbon into smaller independent resonant circuits. Polyhex monoradical skeletons are obtained from a building up procedure which consists to fuse in different ways the acenaphtyl moiety with one or more polybenzenoid fragments. Mathematical formulas are established for three cases of assemblies, one edge linear assemblies, two edges linear assemblies with two linear polybenzenoid fragments located at right angles θ = 60°, 120° or 180° and three edges linear assemblies with three linear polybenzenoid fragments located at right angles θ= 60°, 120° or 180°. Results show that the number of Kekule structures of any polybenzenoid monoradical having only linear assemblies of benzenoid hydrocarbons increases with the number of fused benzenoids according to results compiled in the table for h equal 1, 2, 3 and 4. Difficulty to represent graphs when the number of structures increases with the number of benzenoids cannot be neglected.
{"title":"Enumeration of Kekule Structures of Polyhex Monoradical Having Only Linear Assemblies of Benzenoid Hydrocarbons","authors":"A. Emadak, R. M. Nemba, Leonel Tsassi Djoumessi, Jules Cesar Epee Ndongue","doi":"10.11648/J.SJC.20190703.11","DOIUrl":"https://doi.org/10.11648/J.SJC.20190703.11","url":null,"abstract":"A mathematical process of enumeration of Kekule structures of any polybenzenoid monoradical having only linear assemblies of benzenoid hydrocarbons is given by using a method which consisted of the excision of the radical center in order to obtain a conjugated hydrocarbon having a 12-annulene core ring appended to one or more polybenzenoid fragments, the partition of the resulting conjugated hydrocarbon into smaller independent resonant circuits. Polyhex monoradical skeletons are obtained from a building up procedure which consists to fuse in different ways the acenaphtyl moiety with one or more polybenzenoid fragments. Mathematical formulas are established for three cases of assemblies, one edge linear assemblies, two edges linear assemblies with two linear polybenzenoid fragments located at right angles θ = 60°, 120° or 180° and three edges linear assemblies with three linear polybenzenoid fragments located at right angles θ= 60°, 120° or 180°. Results show that the number of Kekule structures of any polybenzenoid monoradical having only linear assemblies of benzenoid hydrocarbons increases with the number of fused benzenoids according to results compiled in the table for h equal 1, 2, 3 and 4. Difficulty to represent graphs when the number of structures increases with the number of benzenoids cannot be neglected.","PeriodicalId":21607,"journal":{"name":"Science Journal of Chemistry","volume":"111 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90787810","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}
Pub Date : 2019-04-18DOI: 10.11648/J.SJC.20190701.13
I. Ganchev
Biofilms constitute the predominant microbial style of life in natural and engineered ecosystems. At the harsh environmental conditions microorganisms accumulate reactive oxygen species (ROS), potentially encountering a dangerous condition called oxidative stress. An investigation into the mechanisms activated by biofilms in response to different oxidative stress levels could have important consequences from ecological and economic points of view, and could be exploited to propose alternative strategies to control microbial virulence and deterioration. In this respect, the aim if this study is to evaluate the influence temperature and pH of the medium, its osmolality and the presence of heavy metal ions on the growth of the biomass of biofilm formed by B. subtilis 170 and E. coli K- 12 strains and their relationship in them. Тhis study was used the methods for a static cultivation of biofilm by co-cultures of B. subtilis 170 and E. coli K- 12 strains and determination of colony forming units in their structures to evaluate of the relationships between them. The results of the present study show that temperature of 20°C and pH-value in the range of 5.0-6.0 help to maximum growth of biomass of biofilm formed by co-cultivation of B. subtilis 170 and E. coli 1655 strains. The competitive relationships are observed at a temperature of 20°C, at pH-value in the range from 5.0 to 6.0 at low osmolality of the medium of 100 to 150 mM, at content of Fe+ 2 from 5 μM to 100 μM. The increase of the temperature above 30°C and the pH of the medium, the high osmolality of 200 mM triggers antagonistic interactions between B. subtilis 170 and E. coli K- 12 strains, while at content of Fe+ 2 of 50 μM was observed symbiosis in the structure of biofilms in this study.
{"title":"Biofilm Formation Between Bacillus Subtilis and Escherichia Coli K-12 Strains at Acidic and Oxidative Stress","authors":"I. Ganchev","doi":"10.11648/J.SJC.20190701.13","DOIUrl":"https://doi.org/10.11648/J.SJC.20190701.13","url":null,"abstract":"Biofilms constitute the predominant microbial style of life in natural and engineered ecosystems. At the harsh environmental conditions microorganisms accumulate reactive oxygen species (ROS), potentially encountering a dangerous condition called oxidative stress. An investigation into the mechanisms activated by biofilms in response to different oxidative stress levels could have important consequences from ecological and economic points of view, and could be exploited to propose alternative strategies to control microbial virulence and deterioration. In this respect, the aim if this study is to evaluate the influence temperature and pH of the medium, its osmolality and the presence of heavy metal ions on the growth of the biomass of biofilm formed by B. subtilis 170 and E. coli K- 12 strains and their relationship in them. Тhis study was used the methods for a static cultivation of biofilm by co-cultures of B. subtilis 170 and E. coli K- 12 strains and determination of colony forming units in their structures to evaluate of the relationships between them. The results of the present study show that temperature of 20°C and pH-value in the range of 5.0-6.0 help to maximum growth of biomass of biofilm formed by co-cultivation of B. subtilis 170 and E. coli 1655 strains. The competitive relationships are observed at a temperature of 20°C, at pH-value in the range from 5.0 to 6.0 at low osmolality of the medium of 100 to 150 mM, at content of Fe+ 2 from 5 μM to 100 μM. The increase of the temperature above 30°C and the pH of the medium, the high osmolality of 200 mM triggers antagonistic interactions between B. subtilis 170 and E. coli K- 12 strains, while at content of Fe+ 2 of 50 μM was observed symbiosis in the structure of biofilms in this study.","PeriodicalId":21607,"journal":{"name":"Science Journal of Chemistry","volume":"24 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-04-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89404722","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}
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