Isolation of Phthalates and Terephthalates from Plant Material – Natural Products or Contaminants?

Dialkyl phthalates have been used as plasticizers in polymers for decades. As mobile, small weight molecules, phthalates have entered the environment, where they have become ubiquitous. On the other hand, phthalates continue to be isolated from natural sources, plants, bacteria and fungi as bona fide natural products. Here, doubt remains as to whether the phthalates represent actual natural products or whether they should all be seen as contaminants of anthropogenic origin. The following article will review the material as presented in the literature.

Sol-gel Autocombustion Elaboration and Physiochemical Characterizations of Cu2+ Substituted Cobalt Ferrite Nanoparticles

Introduction: The copper doped cobalt ferrite series, with nominal formula CuXCo1-XFe2O4 (X = 0, 0.25, 0.5, 0.75, 1), has been elaborated via sol-gel autocombustion process by copper substitution procedure into cobalt ferrite framework. Methods: The five synthesized ferrites have been analyzed by X-ray powder diffraction, Fourier transform infrared spectroscopy, field emission scanning electron microscopy coupled to energy dispersive X-ray spectroscopy, complex impedance spectroscopy and superconducting quantum interference device magnetometry. Results and Discussion: The analysis of the results allowed to deduce that the cubic spinel basic structure was not modified by the incorporation of copper into the host lattice and the corresponding pure fine powders obtained formed by homogeneous nanoparticles. The highest electrical conductivity value, σDC(373K) = 27.03x10-3S.cm-1, was observed in the case of CuFe2O4. Conclusion: Moreover, the superparamagnetic behavior at room temperature has been confirmed by using both ZFC-FC and hysteresis magnetic measurement modes. In addition, the remarkable electrical conductivity and magnetic properties of the five explored nanoferrites, derived from the present investigation, enabled them useful in several modern nanotechnological and biomedical applications.

Electrocoagulation for the Removal of Copper and Zinc Ions from Water Using Iron Electrodes

Background: Many methods have been suggested for the removal of heavy metals from water to protect human health and the environment. Methods like precipitation and adsorption were proposed for this purpose. Objective: Electrocoagulation involves the generation of coagulant by the action of electricity on two metal electrodes (iron or aluminium) to aid the process of water decontamination. Methods: Electrodeposition cell was made with iron electrodes and application of voltage from the power supply (5-25 V) dipped in the working solution (Cu and Zn) at various concentrations (10-50 mg.mL-1) for 30-150 min. Samples were drawn and analysed by atomic absorption spectrophotometry. Results: The work indicated efficient removal of the metal ions. The dependence of removal efficiency on the three parameters was studied. The behaviour of the two metal ions was not identical. At low initial concentration, the electrolysis voltage was very important in the removal of Zn and Cu ions. Electrolysis time is essential in the removal process and shows a polynomial dependence of removal efficiency on time. Electrolysis time of 150 min resulted in almost complete removal (94-97%) regardless of the initial concentration. Both co-precipitation and adsorption mechanisms may be involved. Conclusion: The removal efficiency was directly dependent on the initial metal ion concentration and electrolysis time. The process gave removal efficiency for copper that is higher than that of the zinc.

Evaluation of Safety, Antileishmanial, and Chemistry of Ethanolic Leaves Extracts of Seven Medicinal Plants: An In-vitro Study

Background: Cutaneous leishmaniasis is a neglected tropical disease that currently affects people among 98 countries and causes significant morbidity and mortality. Current chemotherapeutic intervention is unsatisfactory and has various limitations that highlight the necessity to develop safe and effective therapeutic approaches from natural products. Objective: The main objective of current study was the evaluation of the antileishmanial activity along with toxicity assessment of selected plant extracts. Methods: The ethanolic leaves extracts of selected plants were evaluated for their qualitative and quantitative phytochemical screening by standard protocols. The antioxidant potential of plant extracts was determined by total antioxidant capacity, ferric reducing power and DPPH radical scavenging assays. The cytotoxicity analysis using brine shrimp lethality assay and in-vitro antileishmanial activity against promastigotes of L. tropica (Accession# MN891719) were also evaluated. Results: The preliminary examination of crude extracts revealed that P. armeniaca showed the highest total phenolic and flavonoid content (279.62±5.40µgGAE/mgDW and 205.70 ±2.41µgQA/mgDW, respectively), among others. P. armeniaca showed strongest antioxidants (120.37±4.90 µgAAE/mgDW) and FRP values (278.71±1.03µgAAE/mgDW). All the plant extracts showed cytotoxicity in safety range >1000µg/ml except F. glomerata having LC50 values of 454.34 µg/ml. In the present study, P. communis and P. pashia showed some level of activity (LC50 56.68 and 60.95µg/ml respectively) while P. armeniaca demonstrated the highest antileishmanial activity (LC50 16.18µg/ml). Conclusion: The findings are highly encouraging so, further and extensive investigations of P. arminica should be carried out; especially bio guided fractionation to identify the active fraction and further chemical characterization of structure.

Efficient Removal of Methyl Orange from Wastewater by Polymeric Chitosan-iso-vanillin

Introduction: Water pollution is a serious issue in several countries. In addition, because of limited water resources, the recycling of wastewater is crucial. Consequently, new and effective sorbents are required to reduce the cost of wastewater treatment as well as to mitigate the health problems caused by water pollution. Methods: In this study, the removal of Methyl Orange (MO) dye from wastewater using a chitosan-iso-vanillin polymer was evaluated. The removal of MO from an aqueous solution was studied in a batch system, using the modified chitosan polymer. Results: The results indicate that the removal of MO by the modified chitosan was affected by the solution pH, sorbent dosage, initial MO concentration, contact time, and temperature. The experimental data were fitted to the Langmuir, Freundlich, and Temkin isotherms, and Freundlich isotherm showed the best fit. The kinetic data were fitted to the pseudo-first-order and pseudo-second-order rate equations. Thus, the removal of MO was controlled via chemisorption, and the removal rate was 97.9% after 3 h at an initial MO concentration of 100 ppm and a sorbent dose of 0.05 g. The adsorption behavior of the modified chitosan for the removal of MO was well-described using the pseudo-second-order kinetic model. Intraparticle diffusion analysis was also conducted, and the thermodynamic properties, including entropy (∆S), enthalpy (∆H), and free energy (∆G), were determined. Conclusion: The pH, initial MO concentration, sorbent dosage, adsorption temperature, and contact time had a significant effect on the adsorption of MO by chitosan-iso-vanillin.

Chemical Constituents and Uses of Calotropis Procera and Calotropis Gigantea – A Review (Part I – The Plants as Material and Energy Resources)

The traditional and current use of Calotropis procera and C. gigantea, two soft-wooded, xerophytic shrubs of the family Apocynaceae, are reviewed against the background of the plants' chemical constituents and their biological properties. The focus is on the usage of the plants for building materials, natural pesticides, animal feed and bioremediative purposes.

A Variable Temperature Study of the π–π Stacking Interaction in the Co-Crystal Naphthalene-Octafluoronaphthalene

Introduction: The structure of the 1:1 co-crystal of naphthalene and octafluoronaphthalene, which has been previously determined at room temperature, was determined at 100, 150, 200 and 250 K. Results: Reductions in intermolecular distances and unit cell dimensions are observed on cooling. DFT calculations reveal that the energies of interaction between pairs of molecules vary little with temperature. Conclusion: The strongest interaction is the π–π stacking between virtually parallel naphthalene and octafluoronaphthalene molecules and this displays less change with temperature than the other, weaker, interactions, which have much shallower energy minima.

Evaluation of the Antioxidant Interactions Between Green Tea Polyphenols and Nonsteroidal Anti-inflammatory Drugs

Introduction: The antioxidant interactions between the commonly used pharmaceuticals (diclofenac, ibuprofen and naproxen) and green tea polyphenols were evaluated. Methods: The antioxidant properties of the mixtures were evaluated by a scavenging effect on the 1,1-diphenyl-2-picryl-hydrazyl (DPPH) radical. Results: The mixtures contained green tea extract and each drug exhibited lower antioxidant activity than the mathematical sum of the results obtained for individual components showing antagonistic effect. The results were obtained using isobolographic analysis and interaction factors also suggested the antagonistic type of interaction. Only when the concentration of the green tea infusion was relatively high (in comparison to the drug), an additive effect could be concluded. Conclusion: The high concentration of green tea infusion in comparison to the drug should be used in developing the new formulations as it can help in the therapy due to their antioxidant properties.

Preparation of PbI2 Microflakes by pH-Controlled Double-Jet Precipitation

Introduction: Pure PbI2 crystal particles with a flaky shape were prepared by a pH-constant double-jet precipitation process, which has the significant advantages of easy operation and scaling-up. It was found that a pH below 5.0 of the mixing solution is the appropriate range for the formation of pure PbI2 phase, while at a pH above 5.0, the PbIOH phase would appear immediately and decrease its solubility in DMF (dimethylformamide) for the preparation of a high-quality film of perovskite solar cells. Materials and Methods: Various instruments, including XRD, FTIR, SEM/EDS were used to characterize the precipitated particles obtained under different experimental conditions, and the effect of various parameters, including pH, concentration of the lead ions, feeding rate, and the characteristics of the surfactants on the particle was investigated systematically. Thermodynamic calculation of species distribution in the solution systems of Pb2+-I-- H2O, Pb2+-I--Cit-H2O and Pb2+-I--EDTA-H2O were carried out to identify the indispensable role of pH on the formation of highly pure lead iodide crystals. The crystallization of PbI2 was regarded as the basis of the formation of flake-like products, which was also strongly dependent on the pH value of the solution. Results: It was found that at a low concentration of the PbI2 precursor, such as with very dilute lead ions or with a very slow feeding rate, the XRD reflection peaks at 12.67°, 38.67° and 52.39° will dominate, while the peaks at 25.91°, 34.27°, and 39.51° will become dominant in the case of high concentration. The lead iodide particles were tested by mixing them in DMF, and it was found that the samples precipitated at a pH of 2 and 4 could dissolve and form a homogeneous solution easily, while the sample produced at a pH of 6 would form a turbid suspension, and could not dissolve completely to obtain a clear solution. Conclusion: The results presented in this work provide detailed and significant information about the synthesis of highly pure PbI2 which may be applied in the fabrication of perovskite solar cells.

Synthesis, Characterization and Antifungal Assessment of Optically Active Bis-organotin Compounds Derived from (S)-BINOL Diesters

Background: Organotin(IV) derivatives have appeared recently as potential biologically active metallopharmaceuticals exhibiting a variety of therapeutic activities. Hence, it is important to study the synthesis of new organotin compounds with low toxicity that may be of pharmacological interest. Objectives: This study focuses on the synthesis of new bis-stannylated derivatives with C2 symmetry that could be tested as antifungal agents against two clinical important fungal species, Cryptococcus neoformans and Candida albicans. Methods: The radical addition of triorganotin hydrides (R3SnH) and diorganotin chlorohydrides (R2ClSnH) to bis-α,β-unsaturated diesters derived from (S)-BINOL led to the corresponding new bis-stannylated derivatives with C2 symmetry. Nine pure organotin compounds were synthesized with defined stereochemistry. Four of them were enantiomerically pure and four were diastereoisomeric mixtures. Results: All new organotin compounds were fully characterized, those with phenyl ligands bonded to tin were the most active compounds against both the strains (Cryptococcus neoformans and Candida albicans), with activity parameters of IC50 close to those of the reference drug (amphotericin B). Conclusion: Nine pure organotin compounds with C2 symmetry were synthesized with defined stereochemistry and their antifungal properties were tested against two clinical important fungi with IC values close to those of the reference drug. The structure-containing preferably two or three phenyl groups joined to the tin atom were highly active against both the strains compared with those possessing tri-n-butyl groups.