Phytochemical Screening and Assays of Phenolic Compounds in Senna occidentalis L. Leaf and Seed Extracts

Phytochemical screening and assay of secondary metabolites, crude extracts with distilled water, aqueous methanol, aqueous acetone and aqueous ethanol of leaves and seeds of Senna occidentalis L. were studied in this work. The aim was to verify the distribution of secondary metabolites according to S. occidentalis organs. Four leaf samples from four different localities (South, East, West and Central Senegal) and a mixed sample of seeds were used. Functional molecules such as polyphenols, flavonoids and tannins were then assessed in the leaves and seeds using various standard methods. The results show that Senna occidentalis L. leaf and seed samples display an identical and homogeneous profile, regardless of locality. They contain secondary metabolites and the polyphenol content of extracts from southern, eastern, western and central leaves is: 0.620 - 0.539 - 0.811 - 0.573 g GAE/100 g DM;flavonoids: 0.064 - 0.074 - 0.130 - 0.101 g CE/100 g DM and tannins: 0.326 - 0.264 - 0.269 - 0.494 g TAE/100 g DM. The efficacy of S. occidentalis L. infusions in therapy is thus justified by the presence of these metabolites, whose biological properties are well known. It is then possible to explore isolation of active principles of Senna occidentalis L. leaves and even seeds for producing medicines.

Experimental Study of the Anti-Corrosion Performance of Montmorillonite K-10 on Rebar in HCl Environment: Application in Mortar for the Rehabilitation of Reinforced Concrete Degraded by Corrosion

This work first investigates the corrosion-inhibiting behavior of montmorillonite K-10 on reinforcing steel. The corrosion-inhibiting power of the clay (Montmorillonite) is determined in a medium HCl (C = 1N) using free corrosion potential monitoring, Tafel potentiodynamic polarization curves and electrochemical impedance spectroscopy. The results of this study showed a satisfactory corrosion-inhibiting efficiency of around 72.665% for the optimum content of 1%. This is due to the presence of a stable oxide layer that protects the metal against corrosion. To validate the concept of montmorillonite as a corrosion inhibitor in repair mortar, we now turn to the influence of montmorillonite on the mechanical properties of mortars in the hardened state. In this part, montmorillonite K-10 is added to the mortar by partial substitution of the cement by 5% and 10% of the cement mass. The aim of this study is to ensure that the addition of this clay to the mortar composition will not have a negative effect on its compressive and flexural strengths. The results of the compression and flexural tests showed that the presence of montmorillonite in the mortar improved flexural and compressive strengths for the different compositions studied.

Some Salicylato New Organotin (IV) and Copper Chloride Adducts and Derivative: Synthesis and Spectroscopic Study

Three new salicylate complexes and derivatives have been synthesized and studied by infrared, 119Sn NMR and UV-visible spectroscopies. The suggested structures for the two compounds are discrete with NH-O and NH-Cl hydrogen bonds. The salicylate oxyanion is monochelating for the first salicylate compound with an octahedral tin (IV) centre and monodentate for the second salicylate compound, the environments around the tin centre being tetrahedral. For the cooper complex, the salicylate ligand is monochelating and the environments around the copper atom centre are tetrahedral.

Preparation and Characterization of Activated Carbons from Palm Nut Shells: Effects of Calcination Temperature on Porosity and Chemical Properties

Activated carbons (ACs) calcined at 400˚C, 500˚C, and 600˚C (AC-400, AC-500, and AC-600) were prepared using palm nut shells from Gabon as raw material and zinc chloride (ZnCl2) as a chemical activating agent. Prepared ACs were characterized by physisorption of nitrogen (N2), determination of diode and methylene blue numbers for studies of porosity and by quantification and determination of surface functional groups and pH at point of zero charge (pHpzc) respectively, for studies of chemical properties of prepared ACs. Then, effects of calcination temperature (Tcal) on porosity and chemical properties of prepared ACs were studied. The results obtained showed that when the calcination temperature increases from 500˚C to 600˚C, the porosity and chemical properties of prepared ACs are modified. Indeed, the methylene blue and iodine numbers determined for activated carbons AC-400 (460 and 7.94 mg·g−1, respectively) and AC-500 (680 and 8.90 mg·g−1, respectively) are higher than those obtained for AC-600 (360 and 5.75 mg·g−1, respectively). Compared to the AC-500 adsorbent, specific surface areas (SBET) and microporous volume losses for AC-600 were estimated to 44.7% and 45.8%, respectively. Moreover, in our experimental conditions, the effect of Tcal on the quantities of acidic and basic functional groups on the surface of the ACs appears negligible. In addition, results of the pHpzc of prepared ACs showed that as Tcal increases, the pH of the adsorbents increases and tends towards neutrality. Indeed, a stronger acidity was determined on AC-400 (pHpzc = 5.60) compared to those on AC-500 and AC-600 (pHpzc = 6.85 and 6.70, respectively). Also according to the results of porosity and chemical characterizations, adsorption being a surface phenomenon, 500˚C appears to be the optimal calcination temperature for the preparation of activated carbons from palm nut shells in our experimental conditions.

Aqueous Extract of Ceiba pentandra Stimulates the Production of Fetal Hemoglobin in Sickle Cell Patients

Subsequent studies have demonstrated the reversed activity of the aqueous extract of Ceiba pentandra on the deformity of sickled red blood cells in hypoxia conditions. The observation which related to an in vitro study had given rise to hopes as to the management of sickle cell disease (SCD) by the use of this plant species. In this paper, the authors aimed to investigate the effect of the aqueous extract of C. pentandra on the production of fetal hemoglobin in SCD patients. The work carried out hemoglobin electrophoresis, for a period of six months, on blood samples from SCD patients who voluntarily undergone routine treatment, based on the medicinal recipe prepared from the bark of the trunk and branches of C. pentandra, in a hospital center of herbal medicines located in Kinshasa. The medicinal recipe called BEAT-SS is a patented product of the hospital center named Centre de Phytothérapie Moderne NIECA. Blood samples from patients under treatment were taken to evaluate the behavior of different forms of hemoglobin (hemoglobin S, hemoglobin F and hemoglobin A2). Agarose gel electrophoresis with integrated reading was used for the separation of the different forms of hemoglobin, as well as their dosage on each sample of sickle blood. A reduction in the proportion of hemoglobin S and an increase in the proportion of fetal hemoglobin were found in all sickle cell patients during the treatment period. This observation could affirm that the management of sickle cell patients using the recipe prepared from the aqueous extract of C. pentandra could increase the level of fetal hemoglobin in these patients.

Elimination, Kinetics and Thermodynamics of Fe(II) Ions by Adsorption in Static and Dynamic Conditions on Activated Carbons in Aqueous Media

This work investigated the removal, kinetics and thermodynamics of iron(II) ions (Fe(II)) by adsorption in static and dynamic conditions in aqueous media on activated carbons (AC-i30min, AC-i1h, and AC-i24h), prepared from palm nut shells collected in the city of Franceville to Gabon, using potassium hydroxide (KOH) as the activating agent. Results on the elimination of Fe(II) in static and dynamic adsorption on prepared activated carbons (ACs) showed that the AC-i24h adsorbent has the best Fe(II) adsorption capacities at saturation (Qsat). The Qsat obtained on AC-i24h in static and dynamic conditions (17.87 and 10.38 mg/g, respectively) were higher than those of AC-i30min (13.89 and 5.54 mg/g respectively) and AC-i1h (14.92 and 8.64 mg/g respectively). Moreover, the static adsorption was more effective in the removal of Fe(II) ions in aqueous media in our experimental conditions. The percentage removal (%E) of Fe(II) obtained on prepared activated carbons in static conditions was better than those obtained in dynamic conditions, especially on AC-i24h, where the %E was 89.27% in static and 61.56% in dynamic. In kinetics, results showed that the pseudo-second-order kinetic model best described the adsorption mechanisms of Fe(II) on prepared activated carbons in static adsorption, with mainly of chemisorption on the solid surfaces. However, in dynamic conditions, the pseudo-first-order kinetic model was more suitable. In addition to the weak interactions between Fe(II) and the activated carbon surfaces, strong interactions (chemisorption) were also observed. Also, thermodynamic data obtained on AC-i24h in static adsorption indicated that the adsorption of Fe(II) was spontaneous and increased with temperature (ΔG˚ H˚ = 503.54 KJ/mol).

Thiosemicarbazone (E)-2(1-(2-Hydroxyphenyl) Hydrazine)-1-Carbothioamide: Spectroscopic Studies, Xray Diffractometer Characterization and Antioxydant Test

In the present work, a new semithiocarbazone ligand C3NH4CONHNC(CH3) C6H4OH H4L2 have been isolated and characterized by single-crystal X-ray diffraction. Compound H4L2 crystallizes in the monoclinic system space group P21/n with a = 10.9328(9), b = 8.1700(6), c = 13.8095(11) Å, β = 93.7591(14)˚, V = 3671.57(9) Å3, Z = 16, Z’ = 2. Semithiocarbazone connected through NH···O and OH···O hydrogen bonds. In the crystal, the structure is organized in layer-like arrangements. Structural characterizations were completed by infrared and 1H, 13C{1H} spectroscopy and elemental analysis which corroborate the X-ray elucidations. In another case, this organic compound is submitted to antioxidant test. The test has been done by using Akhtar et al. methods [1] with some modifications. The tests are done with different concentration of solutions between 100 to 500 μM. The values of per cent of inhibition (5.18% - 25.90%) of the solution containing semithiocarbazone organic compound show a real difference compared to the values of the reference TROLOX. These results show that our organic ligand C3NH4CONHNC(CH3)C6H4OH is a good antioxidant compound.

GC-MS Analysis and in vivo Anti-Inflammatory, Analgesic Activities of Phyllanthus niruri Linn and Sida acuta Burm, Used to Treat Malaria in Togo

The use of plants in traditional medicine is an alternative solution to address the adverse effects of conventional anti-inflammatories. This study evaluated the phytochemistry, anti-inflammatory, analgesic and toxicity activities of the hydroethanolic extracts (HE) alone and the combination of Phyllanthus niruri Linn and Sida acuta Burm. Total phenolics were quantified using the Folin-Ciocalteu method, condensed tannin by the Butanol-HCl method, and flavonoid by the Aluminum chloride method. Gas chromatography coupled with Mass Spectrometry (GC-MS) analysis was used to identify several compounds in the extracts. Anti-inflammatory activity and analgesic activity, respectively, were carried out using the paw edema method in rats and pain method induced by intraperitoneal injection of acetic acid in the animal model. Acute, and subacute oral toxicity of extracts was conducted according to OECD n˚423 for the testing of chemicals and n˚407 for testing chemical products. Screening of S. acuta and P. niruri revealed that both of them contain alkaloids, phenolic compounds, terpenes and flavonoids, but P. niruri is richer in total phenols 14.69 ± 0.22 mg GAE/g;proanthocyanidins 4.42 ± 0.01 mg CE/g;and flavonoids 264.21 ± 3.64 mg RE/g. GC-MS analysis was presented for S. acuta 13 and P. niruri 19 compounds. The compounds most represented are levoglucosan (16.01%) and neophytadiene (10.48%) for S. acuta and 2-[(3,4-Dimethoxyphenyl) methyl]-4-methoxy-4-oxobutanoicacid (24%), and (3R,4R)-3-(Benzo[d][1,3] dioxol-5-ylmethyl)-4-(3,4 dimethoxybenzyl) dihydrofuran-2(3H)-one (18.34%) for P. niruri. The concentration of 400 mg/kg recorded the best anti-inflammatory activity. The analgesic effect’s results showed that the hydroethanolic compound at a concentration of 800 mg/kg recorded the highest percentage inhibition (71.60% ± 5.32%) by the oral route. Toxicity results showed that the extracts alone and in combination also did not exhibit signs of toxicity. These results therefore validate the use of S. acuta and P. niruri in traditional medicine.