Study on the Factors Influencing the Extraction of Chenodeoxycholic Acid from Duck Bile Paste by Calcium Salt Method

New extraction technology of chenodeoxycholic acid from duck bile paste by calcium salt was investigated. The optimum conditions of extraction were determined by orthogonal experimental design. The results indicated that influencing factors on the extraction efficiency of chenodeoxycholic acid were as follows: hydrogen peroxide, methyl alcohol, glacial acetic acid, and calcium chloride. The optimum extracting conditions of chenodeoxycholic acid were 1000 mL amount of methyl alcohol, 50 mL amount of hydrogen peroxide, 500 mL amount of 20% calcium chloride, and 600 mL amount of 60% glacial acetic acid for a quantity of duck paste. The yield of chenodeoxycholic acid was 30%.

Phosphorus Speciation by 31P NMR Spectroscopy in Leaf Litters and Crop Residues from Para Rubber, Cocoa, Oil Palm, and Banana Plantations in the Humid Forest Zone of Cameroon

The release of nutrients, including phosphorus from agricultural residues, is an important potential source of nutrients for subsequent crops. To fully understand the contribution of this residue P as a source of plant P for agricultural production, its chemical nature needs to be understood. In this study P species were identified and quantified in leaf litters and crops residues from cocoa farms, oil palm, rubber, and banana plantations by 31P nuclear magnetic resonance (NMR) spectroscopy. Phosphorus in the crop residues was predominantly in the form of inorganic P mainly as orthophosphate and ranged from 45.9 to 89.2%. The highest relative percentage of P as orthophosphate was found in cocoa pod husk (89.2%) and the lowest percentage was found in decaying banana pseudostem (45.9%). Pyrophosphate was detected in trace amounts in all samples (less than 6%) except in fresh palm fronds. However, orthophosphate diester was detected only in fresh palm fronds (11.4%) and phytate was detected only in palm male inflorescence (6.7%). The result implied that cocoa pod husk, palm empty fruit bunch, and palm male inflorescence could be used as organic amendment, based on their high P content and release potential.

A Simple Incorporation Route of Tris(8-hydroxyquinoline)aluminum(III) into Transparent Mesoporous Silica Films and Their Photofunctions

The molecular aggregation states of tris(8-hydroxyquinoline)aluminum(III) (Alq) adsorbed in the transparent mesoporous silica (MPS) films with the different pore sizes (3.0 and 5.4 nm) were successfully clarified. The Alq molecules were easily incorporated into the films from the solution without the segregation on the surfaces. The adsorbed amount of Alq was controlled by changing the added amount in the initial solution to resultantly give the transparent and yellow-color films. The photoluminescence spectra significantly revealed that the state of Alq molecules in the mesopore varied depending on the adsorbed amount of Alq as well as the pore size, suggesting the characteristic mobility of the adsorbed Alq molecules in the mesopores as compared with that at the bulk or solution state. Therefore, the guest-guest interactions between Alq molecules as well as the host-guest interactions between Alq and mesopore were elucidated. This finding by the use of the mesoporous film hosts will be utilized for including luminescence species and be applicable for optical devices.

New Pharmacophore from the Stem Bark Fractions of Acacia decurrens (Willd), an Invasive South Africa Tree

The tolerance of Acacia decurrens, an invasive species, was exploited pharmacologically in this study. Phytochemical screening revealed important secondary metabolites. Importantly, the assay shows that ethyl acetate and methanol fractions are sources of phytochemicals compared to the hexane and chloroform fractions. A bioassay-guided in vitro assay of the extracts led to the eventual isolation of four bioactive compounds by column chromatography, identification, and characterisation with the aid of GCMS, UV-Vis, FTIR, and NMR. The antimicrobial screening by disc diffusion assay revealed 22.2%, 44.4%, 66.7%, and 77.8% microbial inhibition by 2-methyl-octahydro-indene-4-carboxylic acid (AD1), 6-methyldecahydro-1H-phenanthren-9-one (AD2), 8-hydroxytetradecahydro-chrysene-1-carb aldehyde (AD3), and 8,9-dihydroxy-7-(2-hydroxy-ethyl)-9,9a-hexahydro-1H,3H-2-thia-5a-aza cyclopenta[b]anthracen-6-one (AD4), respectively. Compounds AD3 and AD4 are the most potent antibacterial compounds against Gram-positive bacteria with MIC 12.5–6.25 μg/ml. Antioxidant study of the compounds assayed with DPPH and ABTS•+ revealed that compound (AD4) is the most efficient DPPH radical scavenger with IC50 30.07 ± 0.31 and ABTS•+ scavenging activity of 4363.2 ± 452.4 μmol of TE/gDW. This provides scientific information on four pharmacophores with phyto-antioxidants and antimicrobial potential, despite the classification of A. decurrens as a Category 2 invasive plant by the National Water Act.

Removal of Fluoride from Water by Adsorption onto Fired Clay Pots: Kinetics and Equilibrium Studies

Excessive fluoride in potable water is a serious health problem in rural areas of many developing countries. Hence, there is a need to find a simple and cost-effective method for water defluoridation in such areas. In the northern part of Cameroon, clay pots are used for cooking food and water storage. The firing of these pots consists of intensive burning using fire wood. They were tested as a potential adsorbent for removing excess fluoride from water. Experiments were carried out in a jar test at room temperature (25 ± 2°C). Effects of contact time (0–90 min), pH (4, 5, 7, 8, and 9), stirring speed (60, 90, 120, and 200 rpm), and ionic strength (0–1000 mg/L) were investigated. Results showed that equilibrium was attained in 10 min whatever the pH. Pseudo-second-order and pore diffusion models described well the adsorption process. The highest amount of fluoride adsorbed (1.6 mg/g) was obtained at pH 4-5 and the optimum stirring speed is 120 rpm. Ionic strength has a significant effect on fluoride adsorption.

Synthesis and Characterization of CuO, TiO2, and CuO-TiO2 Mixed Oxide by a Modified Oxalate Route

Copper oxide (CuO), titanium oxide (TiO2), and Cu-doped TiO2 nanoparticles have been synthesized by pyrolysis of their corresponding precursors initially prepared by precipitation in aqueous solution using A. carambola fruit juice as a natural source of the precipitating agent (oxalate). The precursors were synthesized and characterized by FTIR, TGA, and PXRD. The results revealed that the precursors obtained were CuC2O4, TiO2(OH−)2C2O4, copper-doped titanium hydroxyl oxalate, and copper titanium hydroxyl oxalate. Complete decomposition for the as-prepared precursors containing titanium ions occurs at 600°C while impurity free copper oxalate decomposed at 450°C. The as-prepared precursors were decomposed and calcined at 600°C for 4 hours and the calcination products were characterized by XRD, SEM, and EDX. The results revealed the decomposition products to correspond to CuO, TiO2, Cu0.131Ti0.869O2, and CuO/TiO2.

Physicochemical Properties of Diacetylenic Light Fuel Oil from Congolese Oleaginous Plant Ongokea gore (Hua) Pierre

Vegetable oil-based fuels are promising alternative fuels for diesel and light fuel engines because of their environmental and economic strategic advantages. In this study, Ongokea gore oil (OGO) and its fully hydrogenated oil were transesterified by means of ethanol in the presence of sodium ethoxide. Fatty acid ethyl esters (FAEE) products were confirmed by 1H NMR and characterized by physical-chemical methods in accordance with the ASTM D 6751 and AFNOR M 15-009 specifications for biodiesels and light biofuels. These methods concern determination of color, density, viscosity, flash and pour points, ash, water and sulfur contents, and corrosion on copper. It was found that pure fatty acid ethyl esters of Ongokea gore oil (B100) and its hydrogenated oil (B100-H) meet standard requirements for most of the biodiesel characteristics studied. Only the kinematic viscosity and density values were outside recommended biodiesel standard limits which makes them unsuitable for use in diesel engines. In accordance with the AFNOR M 15-009 specifications of light fuels, they can be used in light fuel engines. Physical-chemical properties of B20, a FAEE blend in petrodiesel, are within the limits prescribed for petrodiesel standards. In brief, Ongokea gore seeds, a nonedible and high-oil-producing feedstock, are suitable starting material for production of light biofuel. The latter blends in petrodiesel can be used as fuel in diesel engines.

Investigation of Coagulation Activity of Cactus Powder in Water Treatment

This paper is focused on the comparative study of cactus powder, Alum, and their combination of physiochemical analyses of water sample such as TDS, pH, conductivity, salinity, and turbidity using jar test. The result indicated that percentage removal of turbidity from turbid water sample increased from 23.9% to 54% and 28.46% to 58.2% as dose increased from 0.50 to 3.50 g for both cactus powder and Alum, respectively. Cactus powder also has a marginal effect on pH value (7.33 at 0.50 g, 7.49 at 1.50 g, 7.57 at 2.50 g, and 7.57 at 3.50 g) as compared to the usage of chemical coagulants (Alum). The salinity was increased from 0.4% to 0.69 % and 0.39% to 0.98% as the dose of cactus powder and Alum increased from 0.50 g to 3.50 g, respectively. The result revealed that cactus powder is more effective in pH upholding, TDS maintenance, and salinity removal than Alum, but their combination is the most effective in terms of turbidity removal, reduction of salinity, reduction of conductivity, and reduction of TDS and has a marginal effect on dissolved oxygen (DO) value. In conclusion, the combination of Alum and cactus powder is more effective for turbidity removal, salinity removal, and pH and conductivity upholding than either of them used individually.

A Novel Tris(2-aminoethyl)amine Based Tripodal Ligand: Synthesis and Solution Coordination Studies with Trivalent Iron and Chromium

A novel tris(2-aminoethyl)amine (TREN) based tripodal ligand TRENOL (L) has been synthesized and characterized by elemental analysis and UV-VIS, IR, 1H, and 13C NMR spectroscopic methods. The coordination behaviour of the ligand with H+ and trivalent metal ions, Fe(III) and Cr(III), was investigated in aqueous medium at 0.1 M KCl at 25±1°C by potentiometric and spectrophotometric studies. Tripodal ligand showed seven protonation constants in the adopted pH range 2–11 and its electronic spectra exhibited three bands at 216, 323, and 423 nm. Ligand formed various metal complex species of the type MLH5, MLH4, MLH3, MLH, and ML with trivalent metal ions. The determined values of the formation constants (for ML species) of the ligand with Fe(III) and Cr(III) were 24.19 and 18.64, respectively. Molecular modeling studies revealed that the metal complexes formed distorted octahedral geometry. Besides, ligand showed fluorescence at 496 nm when excited at 289 nm. The fluorescence behaviour of the ligand in the presence of Fe(III) ions showed noticeable quenching in comparison to the other metal ions at physiological pH (7.4). So, as per the outcomes of the present study, TRENOL has the potential to be used as the iron detector in environmental, agricultural, and medical fields.

Comparison of Surface and Structural Properties of Carbonaceous Materials Prepared by Chemical Activation of Tomato Paste Waste: The Effects of Activator Type and Impregnation Ratio

Activated carbons were prepared by carbonization of tomato paste processing industry waste at 500°C followed by chemical activation with KOH, K2CO3, and HCl in N2 atmosphere at low temperature (500°C). The effects of different activating agents and impregnation ratios (25, 50, and 100 wt.%) on the materials’ characteristics were examined. Precursor, carbonized tomato waste (CTW), and activated carbons were characterized by using ultimate and proximate analysis, thermogravimetric analysis (TG/DTG), Fourier transform-infrared (FT-IR) spectroscopy, X-ray fluorescence (XRF) spectroscopy, point of zero charge measurements (pHPZC), particle size analyzer, scanning electron microscopy (SEM), energy dispersive X-ray (EDX) spectroscopy, nitrogen adsorption/desorption isotherms, and X-ray diffraction (XRD) analysis. Activation process improved pore formation and changed activated carbons’ surface characteristics. Activated carbon with the highest surface area (283 m3/g) was prepared by using 50 wt.% KOH as an activator. According to the experimental results, tomato paste waste could be used as an alternative precursor to produce low-cost activated carbon.