In the present study, the origin of the anti-quorum sensing (QS) activities
of several members of a recently synthesized and in vitro tested class of
lactone and thiolactone based inhibitors were computationally investigated.
Docking and molecular dynamic (MD) simulations and binding free energy
calculations were carried out to reveal the exact binding and inhibitory
profiles of these compounds. The higher in vitro activity of the lactone series
relative to their thiolactone isosteres was verified based on estimating the
binding energies, the docking scores and monitoring the stability of the
complexes produced in the MD simulations. The strong electrostatic contribution
to the binding energies may be responsible for the higher inhibitory activity
of the lactone with respect to the thiolactone series. The results of this
study help to understand the anti-QS properties of lactone-based inhibitors and
provide important information that may assist in the synthesis of novel QS
The composition of narrow distribution poly ethylene oxide-propylene oxide
copolymer (Mw ~ 8700 Da) was studied using matrix assisted laser desorption
ionization (MALDI) mass spectrometry. The ethylene oxide-propylene oxide
copolymer produced oligomers separated by 14 Da. The average resolving power
over the entire spectrum was 28,000. Approximately 448 isotopically resolved
peaks representing about 56 oligomers are identified. Although agreement
between experimental and calculated isotopic distributions was strong, the
compositional assignment was difficult. This is due to the large number of
possible isobaric components. The purpose of this research is to resolve and
study the composition of high mass copolymer such as ethylene oxide-propylene
SSZ-13 molecular sieve is prepared by the traditional hydrothermal method with silica sol, aluminium sulphate, sodiumhydroxide and deionized water as raw material, and N, N, N-trimethyl-l-adamant ammonium hydroxide as a template. Itis investigated in terms of the influencing factors and optimal reaction conditions, and characterized with XRD, BETspecific surface area meter and FT-IR. The experimental results indicate that the obtained SSZ-13 molecular sieve hasadvantages of shorter reaction time, higher crystallinity and larger specific surface area. The reaction time is furthershortened to 2 days by introducing crystal seed or accelerant, which lowers the total preparation cost of SSZ-13 andmakes its industrialization highly feasible.
A series of some 6H-thiochromeno[4,3-b]quinoline derivatives were prepared by the reaction of4-chloro-2H-thiochromene-3-carbaldehydes with 2-aminophenols in DMF and characterized by analytical and spectralmethods. All the compounds under test were found to be active against M.gypseum and E.floccosum higher than that ofthe standard fluconazole.
An amino chitosan absorbent has been prepared with monoethylamine, chitosan, catalyst, cross-linking agent,hydroxylpropyl chlorination agent and amination agent. This paper discusses the effect of monoethylamine modificationon the amino content in chitosan absorbent, as well as its effect on the absorption capacity of absorbent for Cu2+ andZn2+; and investigates the absorption kinetics of chitosan and amino chitosan for Cu2+ and Zn2+. The results indicate thatthe amino content of modified porous microspheric chitosan is higher than that of chitosan; its absorption capacity forCu2+ and Zn2+ increases with the rise of temperature and changes with pH, and there is no obvious difference inabsorption capacity of Zn2+ between chitosan and modified chitosan.
Solution is prepared by mixing Polymethylmethacrylate in solid form with acetic acid, which at differentconcentration were used to measure density, viscosity & ultrasonic velocity in the temperature range 300C-650C,using ultrasonic interferometer at 1MHz. Using these measured values of density, viscosity & sound velocity,different parameters like, adiabatic compressibility, acoustic impedance and relaxation time have been measuredfor solution of polymethylmethacrylate with acetic acid under different conditions of temperature andconcentration. Variations of above parameters with respect to temperature and concentration have beendiscussed in terms of molecular interactions.
A long chain fatty acid carrying an acryloyl functionality, 12-acryloyloxydodecanoic acid (12-ADA), was preparedfrom 11-hydroxydodecanoic acid and acryloyl chloride and used as monomer in the synthesis of oligomers of 12-ADAvia the RAFT controlled polymerisation process. Reversible Addition Fragmentation Transfer (RAFT) reagents wereprepared and used to control the polymerisation process and produced an oligomeric product with few monomeric unitsinstead of a high molecular weight polymer of 12-ADA. The transfer reagents were prepared from Grignardintermediates from a reaction of dithioacids with free radical initiators 2,2-azobisisobutyronitrile (AIBN) and4,4-azobis(4-cyanopropanoic acid) (ACP). It was found that short-chain oligomers in the form of dimers and trimerscharacterized by Electrospray Mass Spectrometry, ESMS and Gel Permeation chromatography, GPC were the majorproducts obtained when RAFT reagents had been used in the controlled polymerisation. As a control, polymerisationwas carried out in the absence of RAFT reagents and high molecular-weight polymers were obtained. This confirmedthe effectiveness of the prepared RAFT reagents as polymerisation controllers and provided a way for the synthesis ofoligomers. Here, the preparation of oligomers of 12-ADA using AIBN-RAFT reagents is reported. The method isexpected to provide one way of preparing oligomers of controlled chain length/molecular mass which also carry acarboxylic acid functional group at one end.
ABSTRACTInstrumental Neutron Activation Analysis (INAA) has been validated and the method applied to determine total halogen and extractable organohalogen in six fish species namely Heterotis niloticus, Channa obscura, Hepsetus odoe, Tilapia zilli, Clarias gariepinus, and Chrysichthys nigrodigitatus. The samples were collected directly from the fishermen at their landing sites from the two sampling towns, Weija and Nsawam along the Densu river basin in the Greater Accra Region of Ghana. The concentrations of total chlorine, bromine, and iodine analysed by INAA were between 770.70 - 1123.50 mg/kg, 8.00 - 25.00 mg/kg and 0.70 - 4.20 mg/kg respectively. For the extractable organohalogens concentrations ranged from 0.30 – 350.40 mg/kg. The highest concentration of 350.40 mg/kg was obtained for extractable organochlorine (EOCl) in Hepsetus odoe sampled from Nsawam, while the lowest concentration was obtained for extractable organoiodine. The content of extractable organohalogen were in the order of EOCl>> EOBr > EOI. Key words: Neutron activation, Organohalogen, Fish species, Densu basin, Extractable.
This research attempt is made to study the effect of base metal composition in pulse plating of silver over silver alloy.The effect of pulse parameters due to the electro deposition of silver over 50% silver alloy is studied and the results arecompared with the results obtained from the study of the effect of pulse parameters because of the electro deposition of75% silver alloy. The surfaces are characterized by scanning electron microscopy and X-ray techniques. Higher thepurity of silver, finer is the grain size. It is also evident that 75% silver alloy has more corrosion resistant than 50%silver alloy. It is suggested that the properties are improved in pulse plating if the concentration of silver in silver copperalloy is more.
A new one-pot and efficient three-component condensation of aldehyde, ketones, and amines in the presence of MgO/ZrO2 as an inexpensive and effective catalyst for the synthesis of ?-amino carbonyl compounds by Mannich reaction is described. The present methodology offers several advantages, such as good yields, Short reaction times and a recyclable catalyst with a very easy work up. Keywords: Multi-component reaction, MgO/ZrO2, heterogeneous catalyst, ?-amino Carbonyl compounds.
Study the effect of blending hydrophilic agent and water and oil repellent agent on cotton fabric property of antifoulingand easy decontaminating. The study shows that blending could make the fabric have property of antifouling and easydecontaminating.
Three (z)-3-(bromomethylene)thiochroman-4-ones were designed and synthesized. Their structures were confirmed byMS and 1H NMR. In vitro antifungal activities of these synthesized compounds were evaluated against ten species offungi, and the results showed that the target compounds exhibited activity against fungi tested to some extent. Themaximum inhibitory activity was found for 3a against C.neoformans, 3a and 3c exhibited more potent antifungalactivities against C.Krusei than Fluconazole.
A series of chalcones and its cyclohexenone derivatives derived from 6-methoxy-2-naphthaldehyde are described. The chalcones synthesized through Claisen-Schmidt condensation reaction were treated with ethylacetoacetate in presence of NaOH to get the cyclocondensed product ethyl-4-(aryl)-6-(6-methoxy-2-naphthyl)-2-oxo-cyclohex-3-ene-1-carboxylate. The synthesized compounds were characterized from elemental analysis and spectral data. Ethyl 4-(4-chlorophenyl)-6-(6-methoxy-2-naphthyl)-2-oxo-cyclohex-3-ene-1-carboxylate (4f) was studied by single crystal X-ray diffraction.
A simple and accurate method for the quantitative retention of traces of selenium (IV) from aqueous media wasdeveloped employing polyurethane foams (PUFs).The dependences of selenium (IV) uptake by the unloaded andtributyl phosphate (TBP) plasticized PUFs on pH, salt effect, nature and concentration of surfactant, etc. wascritically studied. The sorption data have followed Langmuir, and Dubinin - Radushkevich (D-R) type sorptionisotherms. Thus, "a dual-mode" sorption mechanism involving both absorption related to "solvent extraction"and an added component for "surface adsorption" may be simultaneously present. The sorption and recoverypercentage of selenium (IV) from fresh and natural water by the proposed loaded and unloaded foam columnswere quantitatively achieved. The method was applied for the retention and recovery of selenium (IV) speciesspiked to fresh water employing PUFs packed columns.
A glassy carbon electrode (GCE) modified with valine was used for the sensitive volt metric determination ofepinephrine (EP). The electrochemical response characteristics of the modified electrode toward EP, ascorbic acid (AA)and dopamine (DA) were investigated by cyclic voltammetry (CV). The results show an efficient catalytic activity ofthe electrode for the electro-oxidation of EP, which leads to an improvement to the reversibility of the electroderesponse. The effect of pH and potential sweep rate on the mechanism of the electrode process was investigated. Themodified electrode exhibits an efficient electron mediating behavior along with well-separated oxidation peaks for EP,AA, and DA. Under the optimum pH of 7.0 in phosphate buffer solution(PBS), the CV anodic peak current showed alinear relation versus EP concentration in the range of 4.5×10-6~1.0×10-5mol·L-1 and 1.0×10-5~1.4×10-4 mol·L-1, withcorrelation coefficients of 0.9997 and 0.9942. The detection limit is 7.6×10-7 mol·L-1. High sensitivity and selectivity,submicromolar detection limit, high reproducibility, along with ease of preparation and regeneration of the electrodesurface by simple polishing make this method suitable for the determination of EP in pharmaceutical and clinicalpreparations.
The reactive, macroporous and massive epoxy group-containing polyGMA was synthesized simultaneously withmethanol aqueous solution and nano-calcium carbonate as porogen by bulk copolymerization. After the polymer wassmashed, particles with diameters in the range of 0.30 to 0.45mm were taken as the carrier and the Scanning electronmicroscopy (SEM) micrographs were done to characterize its surface structure. Under the optimum conditions,?-galactosidase was immobilized on the supporter obtained above, the basic property and the kinetic data of all theimmobilized enzyme were determined, and satisfactory results were obtained in enzyme activity, activity yield, pHstability, thermal stability, operational stability, and Michaelis constants Km. The conclusion obtained indicated that theployGMA prepared concurrently with liquid and solid porogen was more suitable to immobilize enzyme than thatpurely with liquid solution as pore-forming agent.
Nickel plating processes, popularly used in Europe in the 1950s, have been increasingly employed in Turkey in recent years. As a result, industrial usage has developed rapidly. Nickel plating is the preferred process for this study because of the uniformity of the plating thickness on the plated surface and the ease with which complex components can be plated. It is also resistant to corrosion and has good levels of hardness.In this experiment, the following parameters were investigated: the effect of varying the amount of nickel, the thickness of the plating, and sheen (whether shiny or dull).In this study, brightener and carrier agents have been used to determine the best operational parameters for the Kale Kilit Factory. The compositions of the brightener and carrier agents used in the experiment are included in this text. Additionally, investigations have been conducted on how the plating color changed when compared to the original bath as a result of using Fe2+ complex concentration in nickel plating baths, as a brightener and for analyzing the color of the plated plate, under a visible region spectrophotometer at 350 nm and 6500 Kelvin light power and D65 (Average North Sky Daylight) light. In our research, the most important feature of analysis is that the desired color effect is obtained by using brightener agents containing Fe2+ complex concentration without any interference from any colorant after nickel plating by electrolysis. In a study where nickel plating bath characteristics are researched, physical tests such as brittle test are applied to the plated plates, which provide us important ideas about the accuracy of the choices made according to standards.
Diglycidyl ether of bisphenol A epoxy resin (DGEBA) was toughened with 5%, 10%and 15% (by wt) of caprolactamblocked methylenediphenyl diisocyanate (CMDI)using 4,4‘- diaminodiphenylmethane (DDM) as curing agent. Thetoughened epoxy resin was further modified with chemical modifier N, N‘-bismaleimido-4, 40-diphenylmethane(BMI).Caprolactam blocked methylenediphenyl diisocyanate was synthesized by the reaction of caprolactam withmethylenediphenyl diisocyanate in presence of carbon tetrachloride under nitrogen atmosphere. Thermal properties ofthe developed matrices were characterized by means of differential scanning calorimetry (DSC), thermo gravimetricanalysis (TGA), heat distortion temperature (HDT) and dynamic mechanical analysis (DMA). Mechanical propertieslike tensile strength, flexural strength and impact strength were tested as per ASTM standards. The glass transitiontemperature (Tg) and thermal stability were decreased with increase in the percentage incorporation of CMDI. Thethermomechanical properties of caprolactam blocked methylenediphenyl diisocyanate toughened epoxy resin wereincreased by increasing the percentage incorporation of bismaleimide. The values of impact strength for epoxy resinwere increased with increase in the percentage concentration of CMDI. The homogeneous morphology of CMDItoughened epoxy resin and bismaleimide modified CMDI toughened epoxy resin system was ascertained from scanningelectron microscope (SEM).
Many technologies have been used to produce finer fibers due to their super advantages such as higher specific surfacearea, filtration/barrier property and absorption, as well as moderate porosity. Finer fibers are thus the great interest ofmany researchers in the nonwoven world, and many technologies have been used to make finer fibers. In this study, theauthors addressed a novel avenue to produce finer fibers by splitting side-by-side bicomponent meltblown nonwovenscomposed of polyethylene terephthalate (PET) and polyamide 6 (PA6) by means of ultrasonic wave, in caustic soda andbenzyl alcohol solutions respectively. The efficiency of fiber splitting was characterized in terms of dyeingratio/percentage of the tested webs. Other properties were also examined, including fiber diameter, web weight loss, airpermeability and thickness. In addition, SEM was used to observe fiber damage and fiber structure in the relevant webs.
In order to solve the problems of the poor binding capacity, forming the aggregate easily between the surface of calciumcarbonate powder and SF/PVA blend system, causing the dispersion inhomogeneous in the organic blending system.The CaCO3-filled SF/PVA blend films were prepared by blending solution with CaCO3 treated with titanate couplingagent. According to IR, the introduction of titanate coupling agent was indeed to crosslink the CaCO3 with PVA and SF.DSC showed that the compatibility of each component of blend films had obviously changed by adding of glycerin.When the content of calcium carbonate was 5wt%, the improving of the tensile strength, elongation at break mechanicalproperties and the stability of wet of blend films had obvious effect. In addition, when the content of titanate couplingagent was 0.3wt%, the blend films exhibited a breaking strength of 45.26Mpa and 832.78% elongation at break,dissolve-loss rates were 2.88%. After the content of titanate coupling agent increased, the mechanical propertiesdecreased and dissolve-loss rates increased gradually.
Pastes containing High Alumina Cement (HAC) and Ordinary Portland Cement (OPC) were prepared using GroundWater (GW) and 5, 10, 15 and 20%SF. The setting time and compressive strength of these admixtured cement pasteswere measured. The hydrated HAC blends were subjected to DTA/TG and DSC analysis. The recorded spectra werecompared with the observed mechanical measurements of these blends. The hydration kinetics is well explainedthrough these results. It is evidenced that 10%SF addition is optimum for this blend.
Perchlorate enclathrated sodalite with gallosilicate host framework has been synthesized under low temperature (100 oC)hydrothermal technique and characterized by X-ray powder diffraction, IR, Raman spectroscopy, UV DRS, SEM, MASNMR spectroscopy and thermogravimetry. The structural features were investigated by IR, MAS NMR spectroscopy of29Si and 23Na nuclei and by Reitveld refinement of X-ray powder diffraction data. IR and Raman spectroscopy confirmsformation of framework and presence of ClO4- group. The tetrahedral framework T-atoms are completely ordered andthe chloride atoms are located at the centre of the sodalite cages. The crystal structure of this new sodalite was refinedin the space group P 4 3n with a = 9.15788 Å, V = 768.5 Å, Z =1, Rwp = 0.0611, Rp = 0.1079 and Si-O-Ga is 144.036o.The surface area of single entity with stoichiometry Na8[GaSiO4]6(ClO4)2 was found to be 8.385x10-15 cm2/g. 29Si MASNMR study confirms complete ordering of Si and Ga in the gallosilicate framework. Thermo gravimetric analysis hasprovided information on the extent of perchlorate entrapment, stability within the cage and decomposition properties.
The efficacy of the preservative chemicals for the treatment of wood samples was evaluated in ground contactagainst termite and fungus. The wood samples treated with boric acid followed by maleic anhydride, copperacetate, sodium salt of diethyldithiocarbamate and kerosene showed higher dimensional stability efficiency interms of anti-shrink efficiency (ASE), bulk co-efficient (BC) and weight percent gain (WPG). The treated woodsamples showed higher strength properties such as modulus of rupture (MOR) and modulus of elasticity (MOE)than the untreated sample. The treated samples could resist from termite and fungal attack and also extend theservice life.
Based on the differences between natural cosmetics and chemical-based products, this essay demonstrates advantagesand disadvantages of the natural cosmetic and the chemical-based product respectively. The natural cosmetic has grownto be a great trend in recent years, the future developing tendency of cosmetic industry should be moreenvironmentally-friendly. Moreover, this essay is prepared in an attempt to give people an advice on choosingcosmetics.
The DNA chemical damage is a very important researching project in chemistry, life science and related fields.In this paper, the biological function of DNA damage, the reason causing damage and the detecting technologyof DNA damage are summarized and discussed.
Soxhlet extraction technique is employed for the extraction and separation of chemical constituents in the medicinalplant, Elephantopus scaber L. The effect of parameters, such as different parts of the plant (leaves, roots and stems),extraction time and types of solvent (n-hexane and methanol) on the extracted yield and the percentage of extractionwere investigated. The design of experiment was done using factorial design. The data were analyzed using ANOVA aswell as factorial design. The experimental results show that the methanol is better than n-hexane but an extraction timeof 9 hours was required for stems and roots while 12 hours for leaves. Essential crude of Elephantopus scaber L.obtained by Soxhlet extraction was further analyzed by gas chromatography-mass spectrometry detection to identify thechemical ingredients of the plant and used as a standard in the qualitative analysis for certain chemical compoundsbased on the retention time on the chromatogram. Six compounds such as stigmasterol, lupeol, stearic acid,deoxyelephantopin isomers, analogue 1 and analogue 2 of deoxyelephantopin have been identified. Oven temperatureprogram of gas chromatography has been developed in this research. The results obtained, enable one to makequalitative and quantitative analysis for the essential oil which was extracted from the herbal plant. Maximumextraction conditions of the stigmasterol and lupeol were determined by comparing the area percentage below the peakin chromatogram with the GCMS standard. Stigmasterol: 6 hours extraction time using n-hexane and stems show thehighest area percentage (8.145%). Lupeol: 9 hours extraction time using n-hexane and stems show the highest areapercentage (68.580%).
eta-lactam fused enediynes have been successfully synthesized by intramolecular Kinugasa reaction in moderate yields.DSC studies indicated significant influence of the eta-lactam ring upon the reactivity of enediynes. None of the eta-lactamfused enediynes (under ring opening conditions) as well as the 11-membered monocyclic enediyne as the tosylate saltshowed any cleavage of plasmid DNA. Interestingly, the 10-membered enediyne as the tosylate salt cleaved both singleand double strands of plasmid DNA at micromolar concentration.
Guanidine was successfully interacted with acetoacetic ester to synthesize 2-amino-4-hydroxy-6-methylpyrimidine
(L1) which on further treatment with phenylisothiocyanate furnishes
1-(4-hydroxy-6-methylpyrimidino)-3-phenylthiocarbamide (L2). The interactions of Cu(II), Cd(II), Cr(II) metal ions
with L1 and L2 have been studied at 0.1 M ionic strength in 70 % Dioxane-water mixture by Bjerrum method as
adopted by Calvin and Wilson, It is observed that Cu(II), Cd(II), Cr(II) metal ions form 1:1 and 1:2 complexes with
ligands (L1 and L2). The data obtained were used to estimate and compare the values of proton-ligand stability
constant (pK.) and metal-ligand stability constants (log k).The effect of substituents were studied from estimated
data (pK & log k).
The nickel(II) and copper(II) complexes of 2-substituted-1-phenyl-1,3-butanedione (2-R-bzacH, R=Cl, NO 2) and their 2,2′-bipyridine (bipy) and 1,10-phenanthroline (phen) adducts have been synthesized and characterized by microanalysis, conductance, magnetic and spectral measurements. The conductivity measurements in nitromethane indicate that the complexes are non-electrolytes while all the adducts are electrolytes except Ni(NO 2-bzac) 2 bipy and Cu(NO 2-bzac) 2 phen which are non-electrolytes. The room temperature magnetic moments suggest that the Cu(NO 2-bzac) 2 is a dimer while the visible absorption spectra of the compounds suggest plausible 4-, 5-and 6-coordinate geometry for these compounds. The infrared spectra of the complexes showed that lower frequency shifts of varying magnitudes were observed in the carbonyl stretching frequencies on complexation.
The complexes of Manganese(II) with 1,10-phenanthroline using the nitrate, thiocyanate and dicyanamide as co-ligands have been synthesized and characterized by elemental analysis, infrared spectroscopy, thermal analysis and room temperature magnetic susceptibility measurements. The magnetic moments of the complexes are consistent with high spin (d5) octahedral geometry. Single-crystal X-ray analysis confirmed the complexes to be [Mn(Phen)2(NO3)2] (1), [Mn(Phen)2(N3)2)] (2), and [Mn(Phen)2(dca)2)] (3). Complexes 1 and 2 crystallize in an orthorhombic crystal system with space group Pbcn while complex 3 crystallizes in the monoclinic crystal system with space group P21/c. The complexes have been screened for in vitro antibacterial and antifungal activities by the disc diffusion method. The minimum inhibitory concentration values indicate that the complexes showed greater activity against the fungi strains tested compared to that of the reference antifungal.
A bilayered glucose biosensor consisting of tris[5-amino-1, 10-phenanthroline]iron(II) polymer film redox mediator and a glucose oxidase layer was prepared on glassy carbon surfaces. The polymer film of the iron complex was immobilized onto the electrode using cyclic voltammetry via electropolymerization reactions, while the enzyme layer was formed using a BSA and glutaraldehyde crosslinking reaction. The biosensors gave the largest response in the pH range of 7-8 and were evaluated with respect to storage conditions of room temperature and 4oC. There was no significant difference between the detection of glucose using the biosensor stored at room temperature versus one stored at 4°C and both bilayered films remained active for 20 days. The detection limit of the biosensors was found to be 0.30 mM which corresponds to a signal to noise ratio of 3:1.
Novel alpha-amino acids bearing 1,2,4-triazinone and steroidal moieties (N,C-disubstituted glycine) (5a and 5b) and the related systems (6 and 7) have been produced from condensation of 6-(8-aminophenyl)-4-phenyl-3-thioxo-1,2,4-triazin(2H)-5-one (1) with the selective steroids, 5-alpha-Androstan-17 beta-ol-3-one (2a) and Transandrosterone (2b) followed by addition of hydrocyanic acid and acidic hydrolysis. A nucleophilic substitution of mercapto group by 4-fluoro aniline and sulfanilamide of 5 afforded the corresponding alpha-amino acids 6 and 7. These newly synthesis compounds are further evaluated for enzymatic effects against some fungi (Cellobiase activity).
Six new Mn(II), Fe(II), Co(II), Ni (II), Cu(II) and Zn(II) complexes with benzoic acid (L) and 4,4,4-trifluoro-1-(2-naphthyl)-1,3-butanedione (L1), of the molecular formulae [MnLL1]·H2O (1), [FeLL1]·H2O (2), [CoLL1] (3), [NiLL1]·H2O (4), [CuLL1] (5) and [ZnLL1] (6), respectively, have been synthesized. The molecular structures of the complexes were determined by spectrophotometric studies using ir, 1H and 13C nmr, es and mass spectrophotometry revealed that the geometries of the complexes 1, 2, 3, and 6 are tetrahedral, while 4 and 5 have square planar geometry. These geometries were supported by their magnetic moments data. The coordination of the ligands to the metal ion are through their oxygen atoms. TGA studies showed that they are thermally stable. Their antioxidant studies revealed that they are good antioxidants.
The synthesis of some 1,3-diazoles and thiazoles was realized in different conditions:a) In the presence of PTSA or sulfuric acid as catalyst we obtained only diazole products(4a-d).b) In basic medium such as DABCO or sodium hydroxide and ionic liquid afforded thiazoles.c) Both products, diazoles and thiazoles were collected when using methanol as catalyst and solvent.All structures were confirmed by IR, 1H NMR and 13C NMR spectroscopy. The antibacterial activity of some synthesized compounds was investigated against Escherichia Coli (ATCC: 25922) and Serratia marcescens (ATCC: 13880) as gram negative bacteria, Bacillus sabtilis (ATCC: 6633) and Staphylococcus aureus (ATCC: 6338) as gram positive bacteria. Some of these products exhibit good activities to significant antibacterial activity.
Previously, an “additivity” equation relating experimental 13 C chemical shift data for two monosubstituted diphenyl-1,3-thiazolidin-4-one series was developed to predict chemical shifts for a similarly substituted bis -disubstituted thiazolidinone series. The sites of interest in the 1,3-thiazolidin-4-one are at the C-2, C-4, and C-5 carbons. The empirically derived equation for predicting the chemical shifts is d XY = d H + (d X -d H ) + (d Y -d H ) where d XY is the predicted chemical shift for the disubstituted thiazolidinone: d H is the experimental chemical shift for the unsubstituted thiazolidinone, d X is the experimental chemical shift for substituent in the 2-phenyl ring, and d Y is the experimental chemical shift for substituent in the N-(3)-phenyl ring. This article discusses the application of the aforementioned equation with respect to a new series of 2-( p -chlorophenyl)-phenyl-substituted-3-phenyl-1,3-thiazolidin-4-oneswith a comparison of both experimental and predicted 13 C chemical shifts for the C-2, C4 and C-5 sites in the thaizolidinone ring. Utilization of the equation showed a level of chemical shift predictability with a degree of accuracy in concert with a previously reported series. The degree of predictability again showed a dependency on the particular substituent and the chemical shift for the site being predicted. This was ±0.06 ppm for C-2, ±0.2 ppm for C-4 and ±0.09 ppm for C5. Finally, there was a correlation between Hammett s values and the substituent chemical shifts using 13 C values at C-2. The r value was -0.86 indicating that the C-2 carbon preferred a positive charge.
A series of 3-benzyl-2-phenyl-1,3-thiazolidin-4-one derivatives, with substituents at the N-benzyl site, was synthesized and characterized. Excluding the p-MeO and m-Br derivatives, distinct correlations between Hammett constant σ and 13 C substituent chemical shifts were observed in the C2, C4, and C5 carbons in the thiazolidin-4-one ring. This was unexpected because the transmission of substituent effects appears to be occurring via the sp 3 hybridized N-benzyl carbon. No discernible correlation was seen for the N-benzyl carbon; the carbon through which the effects were occurring. Correlations for substituent chemical shifts to Swain Lupton substituent parameters r and f constants were also attempted. Similar to the Hammett correlations, C2, C4, and C5 showed a reasonable degree of correlation with minimal to no improvement over Hammett constants; similarly, as with the Hammett correlations, the benzyl carbon exhibited no correlation with Swain Lupton parameters.
S-oxidation of 2-aryl-3-phenyl-1,3-thiazolidin-4-ones with Oxone® was investigated. For all compounds evaluated, selective oxidation to the sulfoxide was realized using 3 equivalents of Oxone® at room temperature. Attempts to selectively prepare the sulfones of ortho-substituted 2-aryl-3-phenyl-1,3-thiazolidin-4-ones at high temperature by increasing the equivalents of Oxone® used were typically unsuccessful. These results contrast significantly with ortho-substituted 2-aryl-3-cyclohexyl-1,3-thiazolidin-4-ones evaluated previously. The extent of this selectivity was affected by the substituent and its position on the C2 aromatic ring. The ratio of the sulfoxide and sulfone products was quantified by isolating the products by liquid chromatography.Please find the scheme in PDF file.
L-Tartaric acid which is chiral compound and commercially available, was converted into 1,3-dioxolane. In the synthetic sequence, 1,3-dioxolane was first formed via protection and partial hydrolysis of L-tartaric acid. Treatment with altered substituted aromatic amines, 1,3-dioxolane gave the desired amides i.e. ethyl 2,2-dimethyl-5-(phenylcarbamoyl)-1,3-dioxolane-4-carboxylate 3a, 2-(4-(ethoxycarbonyl)-2,2-dimethyl-1,3-dioxolane-5-carboxamido)benzoic acid 3b, ethyl 5-(4-iodophenylcarbamoyl)-2,2-dimethyl-1,3-dioxolane-4-carboxylate 3c, ethyl 5-(2-chlorophenylcarbamoyl)-2,2-dimethyl-1,3-dioxolane-4-carboxylate 3d and ethyl 5-(2,4-dichlorophenylcarbamoyl)-2,2-dimethyl-1,3-dioxolane-4-carboxylate 3e. These chiral derivatives were purified through column chromatographic technique and characterized by different spectroscopic techniques i.e IR, 1H NMR, 13C NMR and EIMS. The antimicrobial activities of these compounds were determined at different concentrations against different strains of bacteria and fungi.
S-oxidation of 3-aryl-2-phenyl-1,3-thiazolidin-4-ones with Oxone® was investigated. For all compounds evaluated, selective oxidation to the sulfoxide was realized using 3 equivalents of Oxone® at room temperature. Alternatively, the sulfone was prepared selectively in most of the compounds evaluated at high temperature by increasing the equivalents of Oxone® used; the extent of this selectivity was affected by the substituent and its position on the N3 aromatic ring. The ratio of the sulfoxide and sulfone products was quantified by isolating the products by liquid chromatography.
International Journal of Chemistry wishes to acknowledge the following individuals for their assistance with peer review of manuscripts for this issue. Their help and contributions in maintaining the quality of the journal is greatly appreciated. Many authors, regardless of whether International Journal of Chemistry publishes their work, appreciate the helpful feedback provided by the reviewers. Reviewers for Volume 11, Number 1 Abdul Rouf Dar, University of Florida, USA Ahmad Galadima, Usmanu Danfodiyo University, Nigeria Ahmet Ozan Gezerman, Yildiz Technical University, Turkey Asghari Gul, Comsats IIT, Pakistan Ayodele Temidayo Odularu, University of Fort Hare, South Africa Elnaz Rostampour, Islamic Azad University, Iran Fatima Tuz Johra, Kookmin University, Bangladesh Greg Peters, University of Findlay, USA Ho Soon Min, INTI International University, Malaysia Hongbin Liu, University of Washington, USA Khaldun Mohammad Al Azzam, Batterjee Medical College for Sciences and Technology, Saudi Arabia Maolin Lu, Yale University, USA Merve Kaya, Toros Agri., Turkey Mohamed Abass, Ain Shams University, Egypt Nanthaphong Khamthong, Rangsit University, Thailand Prathapan Sreedharan, Cochin University, India R. K. Dey, Birla Institute of Technology (BIT), India Rabia Rehman, University of the Punjab, Pakistan Sahar A. El-Molla, Ain Shams University, Egypt Sitaram Acharya, Texas Christian University, USA Yu Chen, Henkel Co. Ltd., USA Albert John On behalf of, The Editorial Board of International Journal of Chemistry Canadian Center of Science and Education
International Journal of Chemistry wishes to acknowledge the following individuals for their assistance with peer review of manuscripts for this issue. Their help and contributions in maintaining the quality of the journal is greatly appreciated. Many authors, regardless of whether International Journal of Chemistry publishes their work, appreciate the helpful feedback provided by the reviewers. Reviewers for Volume 11, Number 2 Abdul Rouf Dar, University of Florida, USA Ahmad Galadima, Usmanu Danfodiyo University, Nigeria Ahmet Ozan Gezerman, Yildiz Technical University, Turkey Amer A. Taqa, Mosul University, Iraq Asghari Gul, COMSATS University Islamabad, Pakistan Ayodele Temidayo Odularu, University of Fort Hare, South Africa Binod P Pandey, The Pennsylvania State University, USA Brice Ulrich Saha Foudjo, Catholic University of Cameroon, Cameroon Elnaz Rostampour, Islamic Azad University, Iran Fes Sun Fabiyi, Bowen University, Nigeria Ho Soon Min, INTI International University, Malaysia Hongbin Liu, University of Washington, USA Kevin C. Cannon, Penn State Abington, USA Khaldun M. Al Azzam, Batterjee Medical College for Sciences and Technology, Saudi Arabia Merve Kaya, Toros Agri., Turkey Mohamed Abass, Ain Shams University, Egypt Monira Nessem Michael, National institute of standards (NIS), Egypt Mustafa Oguzhan Kaya, Siirt University, Turkey Nanda Gunawardhana, Saga University, Japan Nanthaphong Khamthong, Rangsit University, Thailand Rabia Rehman, University of the Punjab, Pakistan Rodrigo Vieira Rodrigues, University of São Paulo, Brazil Sie-Tiong Ha, Universiti Tunku Abdul Rahman, Malaysia Sitaram Acharya, Texas Christian University, USA Souheyla Boudjema, University of Tlemcen, Algeria Syed A. A. Rizvi, Hampton University, USA Tony Di Feo, Natural Resources Canada, Canada Zhixin Tian, Tongji University, China Albert John On behalf of, The Editorial Board of International Journal of Chemistry Canadian Center of Science and Education
The genesis of chemical clusters of the transition and main group elements has been established. The base-line for cluster valence electrons has been demarcated with help of capping series. Using the base-line as a reference, the formulas of fragments and clusters were generated. Also a simple general formula for calculating cluster valence electrons for systems ranging from a single to multi-skeletal element clusters was identified. The concepts of the existence of nuclei in clusters and some having black-holes were well established. The capping principle was extended to the main group and transition elements of the periodic table and a difference between metals and non-metals was discerned. The skeletal elements of clusters whose series have advanced beyond closo baseline level S=4n+2 can be separated into two broad groups, namely those which follow the closo series(nucleus) and those which follow the capping series.
International Journal of Chemistry wishes to acknowledge the following individuals for their assistance with peer review of manuscripts for this issue. Their help and contributions in maintaining the quality of the journal is greatly appreciated. Many authors, regardless of whether International Journal of Chemistry publishes their work, appreciate the helpful feedback provided by the reviewers. Reviewers for Volume 13, Number 2 Abdallah El-Gharbawy, Alexandria University, Egypt Ahmad Galadima, Usmanu Danfodiyo University, Nigeria Ahmet Ozan Gezerman, Toros Agri-Industry, Research and Development Center, Turkey Ayodele Temidayo Odularu, University of Fort Hare, South Africa Brice Ulrich Saha Foudjo, Catholic University of Cameroon, Cameroon Farhaoui Mohamed, National Office of Electricity and Drinking Water (ONEE), Morocco Gholam Hossain Varshouee, National Petrochemical Company, Iran Ho Soon Min, INTI International University, Malaysia Kevin C. Cannon, Penn State Abington, USA Khaldun Mohammad Al Azzam, Batterjee Medical College for Sciences and Technology, Saudi Arabia Nanda Gunawardhana, Saga University, Japan Nanthaphong Khamthong, Rangsit University, Thailand Nejib Hussein Mekni, Al Manar University, Tunisia Rafael Gomes da Silveira, Federal Institute of Education, Brazil Rania I.M. Almoselhy, FTRI&ARC, Egypt Severine Queyroy, Aix-Marseille Université, France Sintayehu Leshe, Debre Markos University, Ethiopia Sitaram Acharya, Texas Christian University, USA Tony Di Feo, Natural Resources Canada, Canada Albert John On behalf of, The Editorial Board of International Journal of Chemistry Canadian Center of Science and Education
This study presents the Cs-137 radionuclide concentration and activity in sand profile and seawater samples from Piraquara Beach (PB) and from an adjacent small stretch of sand used as a beach. Both sites are located near the discharge point for cooling water and liquid effluents from the Almirante Álvaro Alberto Nuclear Power Station (CNAAA) in Brazil. The chemical composition of the sand samples was determined by granulometric analysis, elemental chemical characterization, and X-ray diffraction (XRD). Mineral sorbents for the Cs-137 radionuclide were found close to the discharge point. The presence of Cs-137 radionuclides in sand and seawater samples was determined by gamma spectrometry analysis, which was also used for seawater samples after absorption by ammonium phosphomolybdate (APM). The Cs-137 radionuclide activity measurements were lower than the minimum detectable activity (MDA): sand < 0.31 Bq.kg⁻¹, direct analysis of seawater < 0.42 Bq.L⁻¹, and seawater with APM < 0.004 Bq.L⁻¹. The aim of this study was to measure the amount of the Cs-137 radionuclide in the deeper layers of PB. A determination of radioactive exposure to individuals was not performed because the result values were lower than the MDA values. Our results indicate that the study site shows no contamination by the Cs-137 radionuclide.
International Journal of Chemistry wishes to acknowledge the following individuals for their assistance with peer review of manuscripts for this issue. Their help and contributions in maintaining the quality of the journal is greatly appreciated. Many authors, regardless of whether International Journal of Chemistry publishes their work, appreciate the helpful feedback provided by the reviewers. Reviewers for Volume 14, Number 1 Abdallah El-Gharbawy, Alexandria University, Egypt Ahmad Galadima, Usmanu Danfodiyo University, Nigeria Amal A. M. Elgharbawy, International Institute for Halal Research and Training, Malaysia Ayodele Temidayo Odularu, University of Fort Hare, South Africa Fatima Tuz Johra, Kookmin University, Bangladesh Gholam Hossain Varshouee, National Petrochemical Company, Iran Khaldun Mohammad Al Azzam, Al-Ahlyyia Amman University, Jordan Nejib Hussein Mekni, Al Manar University, Tunisia Sintayehu Leshe, Debre Markos University, Ethiopia Sitaram Acharya, Dallas College, USA Tony Di Feo, Natural Resources Canada, Canada Albert John On behalf of, The Editorial Board of International Journal of Chemistry Canadian Center of Science and Education
Three kinds of extraction constants, K ex , K ex ± , and K ex+ , were evaluated from the improved model that the following three component-equilibria were added to a previously-proposed model for an overall extraction: M 2+ + A - ===MA + , MLA + Bz + A - Bz ===MLA 2,Bz , and A - ===A - Bz . Here, K ex , K ex ± , and K ex+ were defined as [MLA 2 ] Bz /([M 2+ ][L] Bz [A - ] 2 ), [MLA + ] Bz [A - ] Bz /([M 2+ ][L] Bz [A - ] 2 ), and [MLA + ] Bz /([M 2+ ][L] Bz [A - ]), respectively; the subscript “Bz” denotes benzene as an organic phase. The symbols correspond to M 2+ = Ca 2+ and Pb 2+ , L = 18-crown-6 ether (18C6) and dibenzo-18C6 (DB18C6), and A - = picrate ion. The ion-pair formation constant for M 2+ + A - ===MA + at M 2+ = Pb 2+ in an aqueous phase was also determined at 298 K and ionic strength of zero by an extraction of HA into 1,2-dichloroethane and Bz with the presence of Pb 2+ in the aqueous phase. The K ex values re-evaluated from the present model were in agreement with those determined by the previous extraction model. Individual distribution constants of A - into Bz were almost constant irrespective of kinds of M 2+ and L employed. Furthermore, the composition-determination method of the ion pairs, MLA 2 , extracted into Bz was re-examined. Similar analyses were performed in the SrA 2 -, BaA 2 -18C6, and SrA 2 -DB18C6 systems without considering the formation of MA + in the aqueous phases.
Nanoparticles of cadmium peroxide (CdO2) were immobilized in poly 2,2 bithiophene (PBTh) to build photoactive inorganic/organic interfaces (I/O/I). Studies indicated that the CdO2 initially immobilized in the organic polymer partially decomposed to a low band gap CdO. Therefore we refer to this mixture as CdO2/CdO. The CdO2/CdO/PBTh assemblies were subjected to optical and photoelectrochemical investigations in aqueous electrolytes containing acetate, nitrate, or phosphate. The equilibrium mixture of CdO2/CdO influenced the optical conductivity and dielectric contents of the assemblies. Furthermore, O2 played an important role in the charge separation and transfer processes. The effects of an applied magnetic field were investigated and reported. The results were explained on the basis of formation of hybrid sub-bands due to band alignments between the assembly components. The photo-induced charge generation of PBTh was improved by occlusion of CdO2 in the polymer as was evident by the greater photocurrent generated by CdO2/CdO/PBTh than that generated by PBTh.
Fluorine-doped tin oxide (FTO) electrodes modified with polymeric films of poly 2,2 bithiophene (PBth) and/or poly 2,2’,5,2’’-terthiophene (PTerth) were subjected to optical, photoelectrochemical (PEC), and electrochemical impedance spectroscopy (EIS) studies. Electropolymerization of mixed monomers containing bi-thiophene (Bth) and ter-thiophene (Terth) with different ratios resulted in the formation of intermixed phases. The recorded optical and PEC and EIS outcome data show that these intermixed polymer networks do not follow a monotonic relationship with the monomer ratios used to generate them. Optical studies indicate the formation of indirect and direct band gaps in the intermixed phases. Films generated in mixed monomers have greater energy-band tails than those generated from pure monomers. PEC studies indicated that these intermixed phases possess p-p type hole accumulations, evident from the initial sharp rise in photocurrent. EIS results did not support linear relationship between the percent of Bth in monomer mixture and the dielectric-related properties such as barrier energy Wm, hopping frequency (ω hopping), electrical conductivity (σ), and density of state at Fermi level N (EF).