New Insights on Chemical Research Vol. 1

Advancement of Fruit Juices as Biocatalysts in Organic Synthesis: A Review

Suman . — 2019-12-10

Facile and green synthetic approaches are important issues in organic synthesis. Green chemistry has become a motivational and inspirational tool for organic chemists to develop mild and benign pathways for the synthesis of biologically active compounds. The naturally available fruit juice as a biocatalyst in synthesis fulfills almost all the terms and conditions of green chemistry and attracted the interest of researchers. Fruit juice is also naturally occurring which are being used as biocatalyst in organic reaction and act as homogeneous catalysts for various selective transformations of simple and complex molecules. Now days aqueous extract of different fruit juice used as biocatalyst in the synthesis of heterocyclic compounds. This growing interest in fruit juice is mainly because of eco-friendly character, non-hazardous, easily available and cost effective. The purpose of this chapter is to look out present aspects of fruit juice in synthesis of potentially bioactive heterocyclic compounds.

Phospholipase A2 Inhibition and Antiinflammatory Activity of F4 Fraction of Total Ethereal Leaf Extract of Annona senegalensis Pers. (Annonaceae)

M. Sene — 2019-12-10

Annona senegalensis Pers. (Annonaceae) is a plant which is used in african traditional medicine for the treatment of various diseases. This study aimed to investigate the analgesic and anti-inflammatory activity of total ethereal leaf extract fractions of A. senegalensis. Compounds of methanolic fractions of ethereal leaf extract of A. senegalensis were separated by gel sephadex chromatography, in five fractions (F1, F2, F3, F4, F5). Experiments were performed in acetic acid-induced contortions in mice, carrageenan rat paw edema and phospholipase A2 inhibitory test. The methanolic fraction of total ethereal leaf extract (10 mg/kg, per os) significantly prevented the carrageenan inflammatory edema. The variation of edema is 22.31±3.35%, 49.66±13.50%, 52.10±10.02% respectively at T1h, T3h and T5h. The increased edema after oral administration of F4 fraction administered at 300 µg/kg and 1 mg/kg per os is respectively 52.77±7.36% and 33.81±6.94%. The variation of edema in betamethasone group (1 mg/kg, per os) is 23.46±3.99%. F4 fraction at 300 µg/kg, significantly inhibited 16.39% of phospholipase A2 enzyme activity. F4 fraction (300 µg/kg, per os) also significantly prevented acetic acid-induced pain in mice. The number of abdominal contortions is 21 versus 72 in control group. F4 fraction compounds have a powerful analgesic and anti-inflammatory activity that involves phospholipase A2 inhibition, comparable to betamethasone profile on pain and inflammation.

Biodiesel Process Intensification

Haruna Ibrahim — 2019-12-10

An investigation on process intensification on biodiesel production was carried with Jatropha curcas seed oil, methanol and five solid base catalysts in a process intensified pilot plant. This Process Intensify Pilot Plant had not the following unit operations as in conventional plants; Neutralizer, Washer, Dryer, Heat exchanger and Condenser to reduce production cost. Five samples of biodiesel were produced with 3 moles of methanol to 1 mole of oil and 1.5 % catalyst loading (w/w of oil). Methyl ester yields of 97.4, 96.94, 95.76, 99.99 and 98.25 % catalyzed by bulk calcium oxide (CaO), super base calcium oxide (CaO/(NH4)2CO3), bulk magnesium oxide (MgO), calcium oxide/magnesium oxide (CaO/MgO) and 10 % impregnated potassium on calcium oxide/magnesium oxide (K-CaO/MgO) were obtained respectively. The products were analyzed in accordance with ASTM, EN and ISO standards for biodiesel and were found satisfactory for use in compression ignition engines. All the biodiesel samples were found not to be easily oxidized as they did not have poly-unsaturated esters such as: linoleate (18:2) and linoleneate (18:3). It was found that this process produced clean biodiesel devoid of glycerol. Also one of the findings from this study is transesterification does not support reversibility.

Synthesis of Ultra-long Hollow Mercury Selenide (HgSe) Chalcogenide Nanofibers from Co and Ni Sacrificial Nanofibers

Nche George Ndifor-Angwafor — 2019-12-10

A general synthetic method has been used to fabricate Co and Ni nanofibers. By using the electrospinning technique followed by galvanic displacement reaction, we have successfully prepared ultra-long hollow chalcogen and chalcogenide nanofibers. The outstanding features of this approach to get ultra-long sacrificial nanofibers with controlled dimensions and morphology, thereby imparting control over the composition and shape of the nanostructures evolved during galvanic displacement reaction are its simplicity, effectiveness and ease of assembly. The aim of this study is to exploit the structural and compositional changes during the formation of HgSe chalcogenide with a view of fabricating a mercury sensor.

Heavy Metals Removal From Spent Synthetic-Based Drilling Mud Using Nano Zero-Valent Iron (nZVI)

Obinduka Felix — 2019-12-10

Management of waste generated from oil and gas activities in the Niger Delta, is a major environmental challenge given that if the spent mud is disposed without proper treatment, the heavy metals will pose a lot of health risks to human through ingestion or inhalation. The heavy metals are also toxic to marine organisms, if disposed into the sea, untreated. Spent synthetic drilling mud is a major waste stream, among its components, are heavy metals. Samples collected on day 0 and biweekly were digested and analysed using the atomic absorption spectrometer (AAS). With nano Zero-Valent Iron, nZVI, concentration of 0.75mg/L of the spent mud, more than 95% removal were recorded for most metals in 6 weeks and over 99% in 12 weeks. The residual heavy metal concentrations met global limits for effluent disposal. Mathematical models with the goodness of fit, R² of 0.999, were developed to predict the removal process.

Physicochemical Properties of Some Vegetable Seed Oils and Their Applications

Michael Akomaye Akpe — 2019-12-10

The physicochemical properties of oils were discussed, and as a case study, extracted from three locally available plant seeds in Nigeria namely: Alchomea cordiforlia, Cyperus esculentum and Irvingia gabonensis using n-Hexane and their properties determined. The results of the analysis revealed that their % yield were 37.00, 27.50 and 33.00 for A. cordiforlia, C. esculentum and I. gabonensis respectively. Their odour was non-offensive and their colours were reddish, light yellow and milky white for A. cordifolia, C. esculentum and I. gabonensis respectively, making them bright and attractive. The specific gravity of the oils at 25°c was 0.91, 0.94 and 0.92 for A. cordiforlia, C. esculentum and I. gabonensis respectively. Their flash points in °C were also 155, 159 and 229 respectively, indicating that I. gabonensis is the most thermally stable oil and suitable for frying. The chemical properties for A. cordiforlia, C.esculentum, and I. gabonensis respectively were as follows: Acid values in mgKOH/g were 24.67, 5.33 and 3.73. Peroxide values in mEqKg^-1 were 7.26, 9.86 and 2.96. Saponification values in mgKOH/g were 162.13, 179.52 and 238.43. Iodine values in g/100g were 24.62, 11.68 and 3.38. These results indicate that the three seeds are viable sources of oil based on their % yield. They are good for both domestic and industrial use based on their acid, saponification and iodine values. Their properties in most cases compete favorably with palm kernel oil (PKO) which is currently being used for many domestic and industrial purposes in Nigeria especially for the making of paints, soap, cosmetics, lubricant and varnishes.

Thermally-Driven Blood Flow in a Bifurcating Artery

W. I. A. Okuyade — 2019-12-10

A thermally-driven oscillatory blood flow in bifurcating arteries is studied. Blood is treated as Newtonian, viscous, incompressible, homogeneous, magnetically susceptible, chemically reactive but of order one; the arteries are porous, bifurcate axi-symmetrically, and have negligible distensibility. The governing non-linear and coupled equations modeled on the Boussinesq assumptions are solved using the perturbation series expansion solutions. The solutions obtained for the temperature and velocity are expressed quantitatively and graphically. The results show that the temperature is increased by the increase in chemical reaction rate, heat exchange parameter, Peclet number, Grashof number and Reynolds number, but decreases with increasing magnetic field parameter (in the range of 0.1≤M²≤1.0) and bifurcation angle; the velocity increases as the magnetic field parameter (in the range of 0.1≤M²≤1.0 in the mother channel and 0.1≤M²≤0.5 in the daughter channel), chemical reaction rate (in the range of 0.1≤δ₁²≤0.5), Grashof number (in the range of 0.1≤Gr≤0.5), Reynolds number and bifurcation angle. The increase and decrease in the flow variables have strong implications on the arterial blood flow.

An Effect of Precursor Concentration on ZnO Thin Films Prepared by Dip Coating Method

K. Radhi Devi — 2019-12-10

Zinc Oxide (ZnO) thin films have been successfully coated onto glass substrates at various solutions concentration (0.1 M, 0.2 M and 0.3 M) by Low cost SILAR coating technique. The film thickness was estimated using weight gain method and it revealed that the film thickness increased with solution concentration values. The prepared film structural, morphological and optical properties were studied using X-ray diffraction (XRD), scanning electron microscope (SEM) and UV-Vis-NIR spectrophotometer respectively. The structure of the films were found to be hexagonal structure with polycrystalline in nature with preferential orientation along (002) plane. X-ray line profile analysis was used to evaluate the micro structural parameters such as crystallite size, micro strain, dislocation density and stacking fault probability. The value of the crystalline size is increased by increasing the concentration of the solution. The average crystalline size was estimated at in the range of 26 nm to 29 nm. The morphological results showed that the concentration of a solution had a significant effect on the morphology of the ZnO thin films. The optical studies revealed that the band gap can be tailored between 3.65 eV to 3.85 eV by altering solution concentration. EDAX studies have shown the presence of zinc and oxygen content. Photoluminescence intensity varies with molar concentration due to the increase of oxygen vacancies. FTIR results conforms the presence of functional group present in the samples.

Chemical Composition and Ovicidal, Larvicidal and Pupicidal Activity of Ocimum basilicum Essential Oil against Anopheles gambiae. (Diptera: Culicidae)

Foko Dadji Gisele Aurelie — 2019-12-10

Background: Malaria remains a serious Public Health threat in the sub-Saharan regions. Although Anopheles gambiae (main malaria vector) has developed resistance against commonly used insecticides, the emergence of this resistance as well as the pollution of the environment by these chemicals have led to the use of plant-derived products such as essential oils.

Aim: This study aimed to characterize and investigate in laboratory bioassays the ovicidal, larvicidal and pupicidal activities of Ocimum basilicum essential oil against aquatic stages of Anopheles gambiae, the main malaria vector in Cameroon.

Methods: Essential oils of O. basilicum fresh leaves were extracted by hydro-distillation, characterized by gas chromatography coupling mass spectrometry (GC-MS) and tested against An. gambiae eggs, larvae and pupal stages in laboratory bioassays.

Results: With an overall yield of 0.31% (w/w), the essential oil of O. basilicum fresh leaves revealed the presence of 29 compounds by GC-MS. Monoterpenes were the main group of compounds found with 1-8 Cineol (33.9%), β-Pinene 16.09%), Terpineol (11.21%) and α-Pinene (5.65%) as the main ingredients. These compounds demonstrated an efficient toxic effect against the aquatic stages of An. gambiae with no egg hatching after 24 hours exposure at >30 ppm. The LC₅₀ values of the essential oil were respectively obtained one-hour and 24-hours post-exposure for first (29.41 and 24.7 ppm), second (34.7 and 17.6 ppm), third (34.7 and 20 ppm) and fourth (45.29 and 23.5 ppm) instars larvae and the pupal stage (45.88 and 36.47 ppm) of An. gambiae.

Conclusion: The essential oil of O. basilicum demonstrated a good efficacy against the aquatic stages of An. gambiae and could be suitable for use in mosquito control programme for a Public Health purposes.

Ultrasonic Investigation of Molecular Interactions in Binary Liquid Mixtures at 298K

G. R. Bedare — 2019-12-10

Ultrasonic velocity, density and viscosity of a binary system of acrylonitrile in 1, 4-Dioxane have been measured at 298 K and 2 MHz. Experimental data of the ultrasonic sound velocity, density and viscosity have been used to calculate various acoustical parameters, such as adiabatic compressibility (β_a), intermolecular free length (L_f), free volume (V_f), excess values of adiabatic compressibility (βa^E), excess values of free length (L_f^E) and excess values of free volume (V_f^E). It is observed from these acoustical parameters that, weak intermolecular interactions are confirmed in this system. Dipole inducement in the system is found to be more predominant. The nonlinear behavior of all these parameters throws more light on the various interactions among the molecules.

Simultaneous Determination of Camylofin Dihydrochloride and Paracetamol Using Differential Pulse Voltammetry in Micellar Media

Emad Mohamed Hussien — 2019-12-10

Simple and sensitive differential pulse voltammetric (DPV) method has been developed for simultaneous determination of camylofin-2HCl and paracetamol. The electrochemical oxidation of camylofin was studied at carbon paste electrode using cyclic and differential pulse voltammetry. A reproducible and reliable oxidation current peak was obtained at pH 7. The oxidation current was enhanced in presence of sodium dodecylsulphate as an erosion reagent. Under optimal conditions the oxidation current was proportional to camylofin concentration in the range from 5.0 to 100.0 µM. Besides, the method was linear for paracetamol which is an active ingredient in the concentration range from 5.0 to 1000.0 µM. The proposed DPV method was selective for simultaneous determination of the two drugs with mean recovery of 99.58±2.13% and 99.44±0.57% for camylofin-2HCl and paracetamol, respectively. The method was validated according to ICH guidelines and successfully applied for the determination of the two drugs in combined pharmaceutical formulations.

Isolation and Characterization of Flavonoids in Urena lobata Leaves

Dixa Singh — 2019-12-10

Aim: Urena lobata L. a member of Malvaceae family, is widely used as famine food in Africa. It is also used in traditional medicine system to cure gonorrhea, fever, wounds, toothache & rheumatism. The plant has already been tested for its antioxidant activity. The work was extended to investigate and identify the flavonoid glycosides present in the plant.

Methodology: Urena lobata leaves were dried, powdered and extracted with petroleum ether followed by methanol. The methanolic extract, after processing through different solvents, was used to obtain the Chemically active constituents .Column Chromatography and Thin Layer Chromatography (TLC) were used to isolate four compounds which were, in turn, subjected to spectroscopic analysis.

Results: The spectroscopic studies indicated that the four isolated compounds are (1) Quercetin, (2) Kaempferol, (3) Quercetin 3-0-rutinoside and (4) Kaempferol 3-0- β glucopyranoside.

Conclusion: The presence of flavonoids in the plant makes it an important ingredient of the traditional medicinal system. Since flavonoids are associated with antioxidant activity, their presence in the plant makes it an important food material.

New Fibrinogenases Isolated From Marine Hydrobiont Adamussium colbecki

Nataliia Raksha — 2019-12-10

Aims: Enzymes that affect hemostasis have been isolated from different sources. Fibrinogenolytic enzymes because of their role in dissolving of blood clots as well as preventionof their formation have attracted special medical and scientific attention. The main goal of current research was to analyze marine hydrobionts (an example of the Antarctic scallop Adamussium colbecki) of the Antarctic region on the presence of potential fibrinogenolytic enzymes.

Methodology: The fraction that consists of fibrinogenases was obtained by affinity chromatography on Blue Sepharose column. SDS-PAGE was applied for the determination of protein composition in the obtained fraction. The proteolytic activity was monitored by the zymographic technique. Fibrinogenolytic activity and activity toward collagen were assessed by incubation of samples with fibrinogen or collagen, respectively followed by SDS-PAGE analysis. To test for substrate specificity, the fraction of fibrinogenases was incubated with p-nitroanilide chromogenic peptides such as S-2366, S-2238, S-2251, S-2222. The fraction of fibrinogenaseswas preincubated with protease inhibitors EDTA, PMSF, and enzymatic activity was measured.

Results:The results clearly indicated the presence of enzymes with activity toward fibrinogen in the extract of A. colbecki. Zymography analysis detected the presence of active enzymes in the region of 27-30 kDa. The fibrinogen cleavage pattern was analyzed by SDS-PAGE under reducing conditions has revealed time- and dose-dependent hydrolysis of fibrinogen. The susceptibility of fibrinogen chains to proteolytic degradation by fibrinogenases from A. colbecki was different. The enzymes preferentially hydrolyzed the Aα-chain; they also cleaved the Bβ-chain but at a slower rate. Collagen was found to be resistant to the action of the fibrinogenases under similar experimental conditions. Fibrinogenases from A. colbecki hydrolyzed chromogenic substrates as S-2238, S-2251, S-2222 and S-2366 but with different specificity. Specific protease inhibitors PMSF and EDTA were used to identify the nature of fibrinogenases present in the tissue of hydrobiont. On the basis of this analysis, the fraction of fibrinogenases from A. colbecki consisted of serine proteases as well as metalloproteases.