Asian Journal of Chemical Sciences

Published by Sciencedomain International
Online ISSN: 2456-7795
Compound (E)- 6-(3-(p-tolyl)acryloyl)- 2H-benzo[b][1,4]oxazin-3(4H)- one [6TABO] with molecular formula C18H15NO3 was synthesized utilizing Claisen-Schmidt condensation technique. FT-IR and 1H NMR spectra were recorded to recognize the different utilitarian gatherings present in the compound and affirm the synthetic construction. The UV-Visible range study uncovers that the visible is straightforward in the whole apparent locale and the retention is seen at 325.40 nm. Single-crystal XRD concentrates on show that the compound takes shape in the monoclinic framework with a space bunch P 1 21/c 1. The corresponding lattice parameters of the crystal are a = 13.0723 (7) Å, b = 7.1789 (4) Å, c = 16.1812 (9) Å, α=900, β = 109.148 (2)0, γ = 900.
Aims: To synthesis new compounds via condensation reactions between 2-methyl quinoxaline-1,4-dioxide derivatives 4,4'-biphenyl carboxaldehyde. Methodology: The Quinoxalines derivatives were prepared from 2-nitroaniline derivatives using the Beirut reaction, and the condensation reaction was carried out at room temperature in absolute methanol. Based on IR and NMR spectroscopic techniques, the structures of all products have been suggested. For their synthesis, suitable mechanisms have been suggested. Results: In this work, condensation reactions involving 2-methyl quinoxaline-1,4-dioxide derivatives and 4,4'-biphenyl carboxaldehyde were performed. Conclusion: The final compounds, we suppose, have considerable applications in fluorescent and chromophoric activities. In all known solvents, the products were just slightly soluble. Products have been subjected to sulfonation reactions, although with limited success.
COVID-19-related disruption in teaching in the University of Botswana led the school to prepare new strategies for running classes and to design innovative way of instruction. The most notable change was to replace face-to-face lectures with online teaching at least partially (blended teaching and learning). This posed many challenges, especially in the teaching of science and technology subjects. In a laboratory-based discipline such as chemistry the problems encountered were especially daunting. Moreover, writing mathematical equations, chemical reactions and reaction mechanisms posed their own difficulties. The present communication provides a brief overview of how chemistry education at the University, the premier national university of Botswana, has been transformed during the last three semesters. It is based on experience of the author and as judged by the feed-back received from colleagues and the students. Admittedly, the experience is limited and much discussion is still in progress to meet the unresolved challenges. Theory classes at undergraduate levels are now mostly taught online using packages such as Moodle and MS Teams. The tutorial and laboratory sessions have faced the greatest disruptions and the instructors continue to explore ways to conduct these virtually. Online examinations were found to be limited in their effectiveness, especially in the assessment of drawing chemical structure and reaction mechanisms as well as the students’ ability in scientific writing.
The identity of the 2-(4-Methyl-2-phenyl-4,5-dihydrooxazol-4-ylmethyl)-isoindole-1,3-dione, previously synthesized in our laboratory, was proven without doubt by means of 1D and 2D NMR spectroscopy. Two-dimensional NMR spectroscopy played a major role. The analysis of the 2D-COSY spectrum of isoindoline-1,3-dione derivative shows a perfect correlation between neighboring protons. Thus, a correlation was noted between the protons of the phthalimide, H(8) and H(9) on the one hand and H(8') and H(9') on the other hand. The analysis of the 2D-HSQC spectrum of the studied compound indicates a faultless correlation between protons and adjacent carbons, and no correlation in the case of all quaternary carbons.
Reaction scheme of DPNP
Packing of the molecules in the unit cell viewed along 'b' axis. The dashed line represents the hydrogen bond
Data collection and refinement details
Scoring Functions obtained via molecular docking simulation
A new chalcone derivative (2E, 4E)-5-(4-(dimethylamino) phenyl)-1-(naphthalen-2-yl) penta-2,4-dien-1-one (DPNP) has been synthesized using Claisen-Schmidt condensation reaction using the slow evaporation method at ambient temperature. The 3D crystal structure was solved using the single-crystal X-ray diffraction method (XRD). XRD study reveals that the title compound crystallizes in a monoclinic crystal system with centrosymmetric space group P21/c with lattice parameters; a = 17.1467(10), b = 11.0395(7), c = 9.5821(5) Å β= 98.43(2)°. The packing diagram shows that the adjacent molecules are linked through a pair of C-H···O hydrogen bonds forming an inversion dimer. Hirshfeld surface mapped over the properties such as dnorm, Electrostatic potential, shape index, curvedness, and energy framework were also analyzed. The in-silico investigation of the title molecule discloses the efficacious for use as a drug in inhibiting breast Cancer.
Weight loss and gasometric methods have been used to study the inhibiting effect of extract of leaves and stem of Solanum xanthocarpum and Salvodera persica on the corrosion of aluminium in 2N HCl solution was evaluated. The results indicated that the corrosion inhibition efficiency increased on increasing plant extract concentration. Percentage inhibition efficiencies obtained from weight loss were reasonably in good agreement with those obtained from gasometric method. The analysis of data shows that combating efficacy of Salvodera persica is more than that of solanum xanthocarpum. However leaves extract of Salvodera persica show more combating power than stem extract of salvodera persica.
In this study, a maize based local snack aadun was formulated from yellow maize flour and ripe plantain blends in a bid to improve its quality. The snacks were subjected to microbial analysis using pour plate method, proximate composition, mineral content and the sensory properties of the snacks were assessed. The results indicated bacterial count ranging from 1.20 to 2.80 x 102 cfu/g. Also, there were no coliforms and enteric bacteria on the aadun samples albeit, there were more bacteria on aadun supplemented with plantain. Two bacteria and three fungi were isolated from the aadun samples, they were Bacillus subtilis, Staphylococcus aureus, Saccharomyces cerevisiae, Aspergillus niger, and Rhizopus stolonifer. The protein and carbohydrate were comparable for the samples while the higher moisture, fiber, ash and carbohydrate were recorded in plantain supplemented aadun with significant increase at a higher content of plantain. Sample C had the highest moisture (6.72%), fiber (7.62%) and ash (2.39%) content in comparison with the other samples whereas, the plain aadun had higher crude fat (32.29%) compared with the aadun containing plantain. The level of calcium and magnesium in the plain and aadun containing plantain were similar without significant differences. However, the level of potassium and phosphorus were significantly higher in aadun supplemented with plantain than in the plain aadun whereas sodium was found to be higher in plain aadun (289.20 mg) than the supplemented samples. There was no significant difference in the appearance and aroma of the plain aadun and plantain supplemented aadun. However, aadun with 50% plantain was ranked as the most preferred samples in terms of taste, texture and overall acceptability with a score of 8.41, 6.31 and 8.33 while the plain aadun had 4.52, 4.22 and 5.79 respectively for these properties. These indicate that aadun may be improved with inclusion of plantainup to 50% proportion.
Variation of conversion parameter with respect to temperature 
Change of band gap due to the change of pressure at 300K temperature
In this article, optical absorbtion and band structure of solid molecular hydrogen at five different phases are reported. Transition pressure for the non-metallic phase to the metallic phase is found at 284 GPA. Phase-IV and phase-V of solid molecular hydrogen are observed as metallic. It is also observed that UV-visible spectra of molecular hydrogen is also changing significantly with the change of pressure.
In order to predict the fate of fluometuron in the aquatic environment and to assess the risk that it may pose, we studied its photolysis reaction in aqueous media. This reaction was monitored by UV absorption and fluorescence spectroscopy. UV irradiation source consisting of a 254 nm mercury lamp was used. The study showed that fluometuron is unstable under the effect of light radiation when irradiated in water. The absorption band and the emission of this product were at 244 nm and 325 nm respectively. This study also shows that the photodegradation of fluometuron in water follows first order kinetics regardless of the method followed. However, a difference was noted in the half-life times (t1/2). Indeed, these times found in UV and fluorescence are respectively 18.2 min and 6.6 min. The relatively lower value obtained in fluorescence could be explained by the fact that the latter is more sensitive to UV and fluorescence. In all cases, the half-lives found were relatively short (t1/2<1h). For more information on the photolysis of this herbicide, these two methods were combined with NMR and GC-MS to identify the different photoproducts that may be formed.
Some of acetoxy derivative compounds [8]
calculated pKa to the experimental pKa of some acetoxy derivatives compounds ( syn-periplanar -positions)
Calculated pKa to the experimental pKa of some acetoxy derivatives compounds (antiperiplanar-positions)
calculated descriptors for the acetoxy derivative compounds (antiperiplanarposition)
The pKa values were calculated for some acetoxy group molecules using CBS-Q method which is one of the Complete Basis Set methods to find accurate energies. The acetoxy group molecules were also planned by Quantitative Structure Activity Relationship (QSAR) to study their effect on paraoxonase1 activity. The results of this study showed a strong relationship, (R2=0.99) between the calculated and experimental pka, also showed correlations between the activity of the enzyme and some of the studied descriptors. Moreover, the results of the study revealed that by using the SPSS program, there is a correlation between LUMO, Softness, Nucleofugality and Electrofugality as dependent variables and Cal. pKa as an independent variable.
The influence of guar gum as inhibitors for mild steel (MS) dissolved in 1.0 M H2SO4 had been investigated via various electrochemical tests at 298 K. Open circuit (OC), Tafel plots had been examined. At first OCP shift found to be more negative values which clarify that guar gum having high efficiency as corrosion inhibitors. The inhibition efficiency (IE%) can be improved with improvement of concentration of inhibitor reaching maximum efficiency up to 89.37% at 298 K. The Tafel plots had been illustrated that a maximum difference of Ecorr 68 mV, that shows that the guar gum worked as mixed type inhibitor. Thermometry investigation shows maximum IE is found to be 86.99.
Mass loss and Scanning Electron Microscope method (SEM) have been used to study the corrosion inhibition efficiency on mild steel and aluminium using synthesized inhibitors i.e. N-Benzylidene aniline (CI1) and N-Benzylidene 4-methylaniline (CI2) in Trichloroacetic acid (TCAA). Study reveals that both mild steel and aluminium are prone to corrosion in organic acid like TCAA. Out of these two metals, aluminium is more vigorously corroded by the TCAA in comparison to mild steel in same conditions and synthesized inhibitors CI1 and CI2 are almost same effective for mild steel and aluminium.
The interpretation of transition state theory via reaction energy profiles is problematical, as it remains unclear whether the energy being represented is the Gibbs energy or the potential energy. Although transition state theory is formally an extension of classical equilibrium theory, employing the Gibbs energy can lead to ambiguities in explaining reactivity trends and differences. Thus, the differential reactivity of the carbonyl group in carboxylic esters and carboxylic acid chlorides, when present in the same molecule, can only be explained by invoking transition state effects because of the common ground state. The said transition state effects, however, apparently need implausible assumptions. It is argued herein that these ambiguities can be avoided by employing potential energy. In particular, by invoking the “localized” potential energy at a reactive center, ground state effects can be brought into play. This is likely to be largely vibrational potential energy, as this is closely involved in bond breaking and making. It appears, therefore, that transition state theory is best viewed in a qualitative sense for it to be practically meaningful. These arguments, in fact, have intriguing implications for catalysis, particularly the theory of enzyme catalysis. Thus, enzymes apparently possess large negative Gibbs energies of formation, hence their reactivity cannot be explained by ground state effects. However, if the “localized” potential energy of the reactive groups in the active site is considered, the phenomenal reactivity of enzymes becomes comprehensible, in an alternative to the Pauling hypothesis of transition state stabilization. This generally implies that the action of catalysts needs to take into account the ground state potential energy of the catalyst, which is almost always ignored in current theoretical treatments.
In this work, Box-Behnken”s Response Surface Methodology (RSM) was applied to study the esterification reaction effectiveness of Ngbo pillarred activated clay catalyst. The esterification was monitored based on temperature, time duration, amount of reactant, catalyst weight, and particle size. The Box--Behnken’s Response Surface Methodology indicates that the pillarred clay-catalyzed esterification reactions proceed through dual Acid-complex and Alcohol-complex mechanisms, with the Alcohol mechanism dominating. The esterification efficiencies of acetic acid and ethanol by acid-activated Ngbo clay catalyst optimized using RSM models indicated the estimated esterification percentage of ˃99%. The predicted and experimental values under the same conditions showed less than 5% difference, making the Box-Behnken design approach an efficient, effective, and reliable method for the esterification of acetic acid with ethanol. The produced catalyst was optimized using A-One way ANOVA modelling, which indicated the correlation coefficient of the regression of 0.8674, implying that 86.74% of the total variation in the esterification reaction was attributed to the experimental variables. The result obtained indicated that the process could be applied in the esterification of acetic acid to avoid the drawbacks of corrosion, loss of catalyst and environmental problems.
Zone of inhibitions: A showing compound 2 against E-coli, B compounds 3 against EColi, C showing 3 against S.typhi and D showing 3 against Staph
Antimicrobial activities
We reported the antimicrobial activities of cobalt and nickel complexes containing imino-NHC ligands. Complex 2 was synthesized by direct reaction of the insitu generated free carbene from 2-[2-(3-benzylimidazol-1-yl)ethyliminomethyl]phenol ligand with NiCl2 diglyme while complexes 3-5 were previously reported as catalysts in the transfer hydrogenation reaction of ketones. The compounds 1-5 were screened for antimicrobial sensitivity test against four gram-negative bacteria Escherichia Coli (E-coli), Shigella, Klebsiella Pneumoniae (K. Pneumoniae) and Salmonella Typhi (S.Typhi) and a gram positive bacteria Staphylocossus aureus (S.aureus). At a varying concentrations of 100, 200, 300, 400 and 500 µg/mL, significant activities were recorded using disc diffusion methods. The cobalt complex 3 was found to have higher activities compared with the corresponding nickel complexes and among the three nickel complexes, nickel complex with pyridine as wingtip was found to be more active than the one with a benzyl group. Similarly, the nickel centre with mononuclear was found to be more active than the tri-nuclear nickel complex. Except for the cobalt complex 3 no activity was recorded against S. typhi for all the nickel compounds.
Chalcones are useful intermediates in the synthesis of heterocyclic compound and the unique reagents in organic synthesis. The usual approach to obtain chalcones is through Claisen-Schmidt condensation. Several novel heterocyclic chalcone analogs have emerged. Chalcones are multifunctional molecules that possess promising pharmacological activities. Chalcones are known for anti-cancer, antioxidant, anti-inflammatory, anti-microbial, anti-tubercular, antileishmanial, antimalarial, anthelmintic, osteogenic activities. This review article focuses on recent applications of Claisen-Schmidt condensation reaction employed in the synthesis of chalcone, its transformation to heterocyclic compounds and pharmacological activities.
Content of polyphenol and flavonoid extracts **P-value is significant at p < 0.05; mean ± S.E.M. = mean values ± standard error of means of three experiments
Background: Bacterial infections are at the origin of a number of serious pathologies, including meningitis, bronchopneumopathies, typhoid fever and especially diarrhea, which are still a real public health problem for the child population in developing countries. In most of these countries, people use medicinal plants for primary health care. The objective of this study was to determine the content of phenolic compounds, the antioxidant and antimicrobial activity of extracts from two plants used in traditional medicine in Burkina Faso, Lannea velutina and Ximenia americana. Place and Duration of Study: Laboratory of Biochemistry and Applied Chemistry (LABIOCA). Methods: The total phenolics and flavonoid content of the ethanolic extract extracts were determined by spectrometric assay. The DPPH and FRAP method were used to measure the antioxidant capacity of the extracts. The antibacterial potential was determined on five bacterial strains. Results: The ethanolic extracts of Lannea velutina showed the best polyphenol content with 969.67±8.23 mgGAE/g extract against 753.145917±66.31 mgGAE/g extract for Ximenia americana. On the DPPH radical Ximenia americana gave the best activity with a percentage inhibition of 62.32±0.17% compared to Lannea velutina. This species also gave the best reducing activity with a reducing capacity of 3.45±0.97 mmol EAA/10 g of extract. Shigella dysenteria and Staphylococcus aureus were susceptible to Lannea velutina and Ximenia americana with inhibition diameters greater than 8 mm. Conclusion: These results showed that the extract has good antioxidant potential as well as antimicrobial activity. These extracts could be used to prevent damage from oxidative stress and infections.
Cellulose isolated from Eichhornia crassipe (Water hyacinth) and Pennisetum purpureum (elephant grass) were evaluated using Fourier Transform Infra-Red spectroscopy and standard analytical methods for production of drilling mud. The physico-chemical analyses were carried out after chlorination and alkaline process using sodium chlorite and sodium hydroxide for the extraction of cellulose from the two biomass samples under same experimental conditions. Results of physico-chemical analysis of Eichhornia crassipes showed pH: 7.30; conductivity 0.028; bulk density 0.1097g/ml. Pennisetum purpureum showed pH: 7.50; conductivity 0.192; bulk density 0.1378g/ml. Pennisetum purpureum has a higher cellulose yield of 31.39% compared with Eichhornia crassipes with a percentage cellulose yield of 21.88%. Both biomass samples have Herzberg strain of Violet-blue. The results of the Fourier Transform Infra-Red spectroscopy showed prominent peaks at 3353-3164, 1655, 1629, 1320, 1033 and 1019 cm-1. The broad absorption bands around 3353-3164 cm-1 indicated stretching of –OH groups due to inter-molecular and intra-molecular hydrogen bonds of polymeric compounds. The sharp bands at 1655 cm-1 and 1629 cm-1 showed C=C stretch of aromatics. The sharp absorption bands observed at 1320, 1019 and 1033 cm-1 were characteristic of C—O stretch and C—O—C asymmetric stretch of cellulose. The FTIR results proved that the products extracted from the two samples were aromatic hydroxyl compounds. The results of the physicochemical analyses showed that cellulose isolated from the biomass samples which are persistent noxious weeds that invade the aquatic and terrestrial environment can be utilized in industrial applications for drilling fluid production.
Bio-phenol formaldehyde (BPF) resole resins were characterized by liquid-state 13C Nuclear Magnetic Resonance (NMR) spectroscopy. The liquid 13C NMR analysis indicated that the condensation reactions between the bark phenolic compounds and the formaldehyde occurred during the synthesis of the resins. Methylene ether bridges in the resins were more pronounced in the BPF resin when compared to the PF resin system. The liquid-state 13C NMR study revealed significant differences in the resins structures induced by the inclusion of bark-phenolic components. The bark-phenolic components favored the formation of para-ortho methylene linkages in the BPF resins and also enhanced the cure rate of the BPF resin system.
In this work, a series of poly(Hexanediol adipate)(PHA) samples (103<Mn<104) with narrow molecular weight distribution were prepared by the polymerization between adilic acid and 1,6-hexandiol. End-group analysis was applied to determine the number average molecular weight (Mn) of PHA. Gel permeation chromatography (GPC) was employed to obtain the average molecular weights (Mn, Mv, Mw).The intrinsic viscosity of the samples in the tetrahydrofuran (THF) solution was determined at 298 K by the dilution extrapolation method and the one-point method. The relationship between the intrinsic viscosity and the molecular weight for PHA was studied by the Mark-Houwink-Sakurada (MHS) equation, and the parameters of equation were determined.
Millions of people worldwide are adversely affected by Arsenic continuing exposure, so providing arsenic-free consumption of water is an immense task for the researchers. The chemistry, content of arsenic-contaminated water as well as adsorption play a big role in arsenic elimination. The mechanism of adsorption technology's elimination of As (V) from the water was simply presented as the elements that govern various adsorption paths. The effects of a variety of adsorbents on As (V) elimination from aquatic were explored in the present research, which classified the materials used as adsorbents based on physical, chemical, and biological processes. When choosing an adsorbent, adsorption capability is an important factor to consider. As a result, developing As (V) elimination from aquatic adsorption strategies includes developing environmentally acceptable materials with effectual adsorption abilities, refining the preparation and alteration procedures of recent adsorbents, and boosting renewal effectiveness. After choosing a particular adsorbent for As (V) elimination from water, regional features of arsenic-polluted water, applied viability of the adsorption process, besides suitable environments of respectively material must be extensively reviewed and analyzed. The current study gives an outline of the adsorption technique to remove arsenic from wastewater, as well as the adsorption capacity of various adsorbents.
Among the various methods available for wastewater remediation, the adsorption technique remains one of the most preferred choices worldwide. This is because the process is effective and economically feasible. Over the years, the abundance and availability of agricultural waste products have encouraged their application in pure or modified forms as catalysts in environmental remediation. Such agricultural wastes are carbonaceous and lignocellulosic in nature with numerous surface functional groups which makes them favorable for use as adsorbents for the removal of various pollutants. Rhodamine B (RhB) dye is a common organic dye in industrial wastewaters but could be artificially removed via adsorption. In this article, the use of agricultural-waste based adsorbents for the removal of RhB dye from aqueous solution over the last decade have been reviewed.
Water pollution has great impact on environmental degradation. Release of untreated wastewater containing toxic metal ions into natural waters is a threat to aquatic ecosystem and is attributed to affect the health of living things. Date nut carbon was analysed as an adsorbent for extracting Cr(VI) ions from wastewater using batch method. Investigations were done by varying the pH from 1 to 6, carbon dose from 0.1 g to 0.5 g and equilibration time from 1 to 24 hours. Cr(VI) removal of 93% occurred at an optimal pH of 2, carbon dose of 0.3 g/100mL, and equilibration time of 3 hours. The adsorption of Cr(VI) on Date nut carbon followed first order kinetics. The kinetic process of Cr(VI) adsorption onto Date nut carbon was tested by applying first order kinetics.
Effect of contact time on the adsorption of Bromocresol green dye
Effect of initial dye concentration on the adsorption of Bromocresol green dye
Effect of pH on the adsorption of Bromocresol green dye
Kinetic table for the adsorption process
Background: The adsorptive removal of anionic dye (Bromocresol green) from aqueous solution was investigated using activated carbon prepared from rice husk. Place of Study: The research work took place at Nnamdi Azikiwe Univeristy Awka, Nigeria. Methods: The rice husk which was obtained from rice mills in Awka was activated with tetraoxophosphoric acid and carbonized in a furnace. The adsorption process was investigated by varying the contact time, temperature, dosage, pH and initial concentration in a batch process. Five isotherm models (Langmuir, Freundlich, Temkin, Halsay and Harkin-Jura) were employed in the equilibrium studies. Thermodynamics and kinetics of the adsorption were carried out. Results: The result indicated that increase in contact time, adsorbent dosage and temperature increased the percent uptake of the Bromocresol green dye. Maximum percentage adsorption of about 93% was obtained. Langmuir and Harkin-Jura isotherm models best described the equilibrium data of the adsorption process. Pseudo second-order kinetic model best correlates the kinetics of the experimental data. The thermodynamic study showed that the Gibbs free energy (ΔG), enthalpy change (ΔH) and entropy change (ΔS) were –2.541 kJ/mol, -7.401 kJ/mol and –15.52 kJ/mol K respectively. Conclusion: This work has shown that activated carbon prepared from rice husk can be used in adsorptive removal of bromocresol green dye from solution and that the adsorption process was spontaneous and exothermic.
The adsorption behavior of sodium bisulfate on silica gel was studied. The adsorption isothem of sodium hydrogen sulfate on silica gel were measured in the temperature range of 298.15 ~ 328.15 K, and the Langmuir model and the Dubini-Radushkevich (D-R) model were used to fit the experimental isotherm data. The average characteristic concentration (Ce') of NaHSO4 was determined at different temperatures to distinguish chemisorption from physisorption. The values of the mean free energy (E) calculated from the D−R isotherm equation indicated that the adsorption of NaHSO4 on silica gel occurs by sequential chemical and physical mechanisms.
Cons and Pros of ZnO NPs application with natural materials 
This review was aimed to highlight the role of ZnO and TiO2 nanoparticles (NPs) as textile protective agents against Ultra Violet radiation. Different synthetic methods of ZnO and TiO2 NPs that affecting their nano size and their ability to absorb UV radiation have been reported. The formed ZnO or TiO2 NPs can be applied on treated or untreated fabrics individually to provide UV protection or in combination with other materials to provide multifunctional finished fabrics. Cons and Pros of each application process in addition to comparison of the methods of preparation of ZnO and TiO2 NPs were discussed separately in this review paper.
Nanoscience and Nanotechnology are highly growing their significance in diabetic supplies and research nowadays. It is an area that included nanomaterials, nanosensors and nanostructures as well as nanoparticle projects and also their usage in human health research. Particularly, nanotechnology helps to the production of diabetic supplies, materials together with the development of novel glucose and insulin injection devices as well as their measurement sensors by the aid of nanomaterials. These materials mostly could be metal nanoparticles together with carbon nanostructures by nano dimension delivery mechanisms modalities which hold the potential to vividly recover the excellence of life of diabetic patients. Nanoscience and nanotechnology in diabetic research have facilitated and provided more truthful data for identifying diabetes mellitus. It is also worth mentioning that the nanotechnology could highly enhance the impact of drug delivery by addition of nanoscale materials and increase the glucose feeling, temporal response as well as glucose nursing. Furthermore, it is proposing novel nanoscale methods named closed-loop insulin delivery approaches which mechanically release insulin drug in reply to fluctuating blood glucose heights. Besides, the mixture of nanotechnology by medication has shaped a novel field of nanomedicine which could enhance human health level. It is worthwhile to mention that some of the applications of nanotechnology for the treatment of diabetic patients can be the production of diabetic supplies by nanotechnology. One of the most important diabetic instruments that could highly relieve the life of patients these days could be nano diabetic shoes which will describe here. In this research, applications of nanoscience and nanotechnology in treating diabetic patients were discussed.
Aims and Objectives: To determine the effect of extracting solvents on the physicochemical properties of oils extracted from four locally available plant seeds in Nigeria namely: Alchornea cordiforlia, Hura crepitans, Irvingia gabonensis and Pycnanthus angollensis using three different solvents namely; n-Hexane, Petroleum ether and Dichloromethane. Place and Duration of Study: Department of Chemistry Laboratory, University of Calabar, Nigeria. The study was carried out between August 2019 and December 2019, (5 months). Methodology: Each plant seed was ground into a paste and extracted for its oil using a Soxhlet extractor and three different solvents namely; n-Hexane, Petroleum ether and Dichloromethane. The physicochemical properties of the oils were then analysed. Results: The results revealed the mean values of the physicochemical properties of A. cordifolia oil extracted using Hexane, Petroleum ether and Dichloromethane respectively were % yield (36.50, 34.50 and 32.00), specific gravity (0.91, 0.91 and 0.92), flash point (156.00, 155.00 and 191.00°C), Acid value (23.76, 25.10 and 26.80 mEqk-1), % free fatty acid (11.88, 12.55 and 13.40), Peroxide value (6.56, 6.38 and 6.90 mEqK-1), Saponification value (163.20, 156.40 and 165.50 mgKOHg-1) and iodine value (25.40, 48.60 and 46.50 g/100 g). The mean values of the properties of H. crepitans oil across the 3 solvents respectively were % yield (32.20, 31.50 and 29.00), specific gravity (0.92, 0.93 and 0.94), flash point (271.00, 259.00 and 240.00°C), Acid value (21.00, 21.80 and 22.20 mEqk-1), % free fatty acid (10.50, 10.90 and 11.10), Peroxide value (5.85, 6.26 and 7.10 mEqK-1), Saponification value (172.50, 190.40 and 185.60 mgKOHg-1) and Iodine value (43.60, 34.50 and 26.90 g/100 g). Properties of the I. gabonensis oil were % yield (33.20, 34.00 and 32.50), Specific gravity (0.92, 0.94 and 0.94), flash point (230.00, 236.00 and 260.00°C), Acid value (3.72, 3.70 and 3.90 mEqk-1), % free fatty acid (1.86, 1.85 and 1.95), Peroxide value (2.98, 4.26 and 3.63), Saponification value (239.50, 252.40 and 245.80) and Iodine value (25.30, 11.70 and 44.20). Mean values of P. angollensis oil properties were % yield (34.10, 36.20 and 33.00), Specific gravity (0.92, 0.92 and 0.93), flash point (260.00, 258.00 and 256.00°C), Acid value (23.68, 25.00 and 26.00 mEqk-1), % free fatty acid (11.84, 12.50 and 13.00), Peroxide value (4.25, 5.30 and 5.96), Saponification value (25.30, 52.50 and 57.30) and Iodine value (25.20, 11.68 and 44.40). The odour, colour and physical state of all the oils at room temperature was the same across the 3 solvents. Conclusion: The results indicate that the physicochemical properties of the oils vary with the extracting solvent and its polarity. Their properties revealed that some of them can be used for many domestic and industrial purposes especially for the making of paints, soap, cosmetics, lubricants and varnishes.
The purpose of this study was to investigate a continuous process for the recovery of lactic acid from fermentation broth. A reactive distillation process to purify lactic acid by esterification with isoamyl alcohol and hydrolysis was designed and simulated by Aspen. Five columns were included in the process: esterification column, purification column, hydrolysis column, dehydration column and recovery column. Effects of process parameters (operating pressure, feed composition, feed position, number of reaction and separation stages, and reboiler duty) of the esterification column on the yield and purity of lactic ester was evaluated. Further evaluation was carried out to reveal the effects of process parameters of the hydrolysis column on the yield and purity of lactic acid. The total annual cost of the whole process was calculated. Simulation studies are carried out using Aspen Plus RADFRAC module. It was shown that under the optimized condition, the concentration of lactic acid can reach up to 82.4 wt%, and the organic acid impurities were less than 3 ppm. Compared with the traditional usage of methanol and butanol, the isoamyl alcohol process can save about 20% of the total annual cost at the same output of lactic acid. Results obtained in this work can be used for scale-up study of an industrial reactive distillation operation as an efficient and economical alternative to recover lactic acid from fermentation broth.
Aim and Objectives: Nowadays, nanomaterials technology is developing very quickly and bringing high economic efficiency for many industries including paint. The purpose of this study is to assess the effect of paint properties when replacing TiO2 powder coating with nano TiO2 at different ratios. Materials and Methods: The research method is selecting the traditional alkyd paint formula, then replacing this coating powder TiO2 with nano TiO2 to monitor the properties of the paint film over time. Methods of analyzing the properties of the paint film are based on Vietnam standards. Results: The study results showed that TiO2 coating powder replaced by TiO2 nanomaterials has increased the properties of the paint film, improving the thickness, gloss, and durability of the paint film. Nano TiO2 increases from 0.5% to 24% by weight, the impact increased by about 11% (73 to 82, Glossy 60° increased by about 12%, Glossy 85° increased by about 12%, especially the durability of paint film over time increased nearly double. Nano TiO2 is a more expensive material than TiO2, so it should replace less than 4% by weight to increase the quality of the paint film, this ratio is changed according to the actual equipment requirements. Conclusions: The higher the rate of replacing TiO2 materials with TiO2 nano, the better the properties of the paint film. Therefore, nano-material TiO2 is a good coating in alkyd resin for metal paint, it improves the properties of paint film better than TiO2 material.
The objective of this research is to investigate number and types of bioactive compounds present in Aloe Vera buds grown in North East Punjab region of Pakistan by FTIR which is simple, nondestructive, cost effective and user friendly. Aloe vera was cultivated under normal atmospheric conditions. After two years, buds (early stage of flowers) were grown on twigs. The buds were plucked and blended with distilled water in National Juicer machine to have a concentrated blend. The blend was filtered to get clear solution, mixed with ethyl acetate and then solvent extracted. The organic part was isolated and dried at water bath at 60°C. Dried sample was analyzed using FTIR spectroscopic analysis. All activities were performed consecutively to avoid photochemical changes. The characteristic FTIR spectral lines have shown different characteristic peaks that correspond to different functional groups indicating presence of bioactive compounds like substituted cyclic alkanes, alkenes, alcohols, phenols, and aromatics etc. have been investigated.
Background: Previous research has shown that the intrinsic reverse (backward) and forward rate constants are larger than the effective or apparent rate constants for the formation and dissociation of an enzyme-substrate complex (ES). It is speculated that such intrinsic rate constants could be larger if an appropriate mathematical equation was adopted for their computation. Methods: Theoretical, experimental (Bernfeld method), and computational methods. Objectives: 1) To rederive the equations for calculating the intrinsic rate constants for forward (k1) and reverse (i.e., backward) (k2) reactions; 2) to calculate the intrinsic rate constants; and 3) to show that the probability (1/g) (or req(r)) that an enzyme is at a distance from the substrate is a variable. Results and Discussion: The equations for the determination of k2 and k1 were rederived. Unlike previous findings, the intrinsic (reverse) first order rate, k2 and forward second order rate, k1 were larger than their apparent counterparts, but they were, however, very similar in magnitude. The intrinsic rate constants were much larger than previously reported values when the enzyme (E) total concentration [ET] was much less than substrate’s total concentration [ST]. The k1 and apparent forward second order rate (kf) values where [ET] is much less than [ST] were > where [ET] is less than [ST]. Therefore, the magnitude of the second order rate constant is a function of [ET]. The values of k1 and k2 where [ET] is much less than [ST] and vice-versa were respectively, 7.41 exp. (+6) L/mol. min and 81.34 exp. (+4) /min, and 15.76 exp. (+6) L/mol. min and 58.08 exp.(+4) /min. It was discovered that the probability (1/g) (or req(r))) that an enzyme is at a distance from the substrate with the possibility of mutual attraction is not constant. Conclusion: If the intrinsic forward rate constant (k1) is not equal to diffusion limited rate (kD) of encounter, the k1 and k2 values could be larger than values where k1 is equal to kD. The probability (1/g) (or req(r)) that an enzyme is at a distance from the substrate with the possibility of mutual attraction has been discovered to be a variable constant dependent on the concentration of the reaction mixture components and the enzyme's affinity for the substrate, and vice versa. Future research may attempt to derive an equation for the determination of an intrinsic catalytic rate constant for the formation of a product.
Top-cited authors
Md.Kudrat-E- Zahan
  • University of Rajshahi
Md. Masuqul Haque
  • University of Rajshahi
Md. Saddam Hossain
  • Begum Rokeya University, Rangpur
Onu Elijah
  • Nnamdi Azikiwe University, Awka
J.T. Nwabanne
  • Nnamdi Azikiwe University, Awka