The Multifaceted Role of Curcumin in Advanced Nanocurcumin Form in the Treatment and Management of Chronic Disorders

Curcumin is the primary polyphenol in turmeric’s curcuminoid class. It has a wide range of therapeutic applications, such as anti-inflammatory, antioxidant, antidiabetic, hepatoprotective, antibacterial, and anticancer effects against various cancers, but has poor solubility and low bioavailability. Objective: To improve curcumin’s bioavailability, plasma concentration, and cellular permeability processes. The nanocurcumin approach over curcumin has been proven appropriate for encapsulating or loading curcumin (nanocurcumin) to increase its therapeutic potential. Conclusion: Though incorporating curcumin into nanocurcumin form may be a viable method for overcoming its intrinsic limitations, and there are reasonable concerns regarding its toxicological safety once it enters biological pathways. This review article mainly highlights the therapeutic benefits of nanocurcumin over curcumin.     

Electrochemical properties and radical anions of carbocycle‐fluorinated quinoxalines and their substituted derivatives

Electrochemical reduction (ECR) and oxidation (ECO) of 5,6,7,8‐tetrafluoroquinoxaline ( 1 ) and its derivatives bearing various substituents R (7‐H ( 2 ), 7,8‐H₂ (3 ), 6‐CF₃ ( 4 ), 6‐Cl ( 5 ), 5,7‐Cl₂ ( 6 ), 5‐NH₂ ( 7 ), 6‐OCH₃ ( 8 ), 6,7‐(OCH₃)₂ ( 9 ), 6,7,8‐(OCH₃)₃ ( 10 ), 5,6,7,8‐(OCH₃)₄ ( 11 ), 6‐OCH₃,7‐N(CH₃)₂ ( 12 ), 6‐N(CH₃)₂ ( 13 ), 6,7‐(N(CH₃)₂)₂ ( 14 ), 5,6,7‐(N(CH₃)₂)₃ ( 15 ), and 7,8‐cyclo‐(=CF‐CF = CF‐CF=) ( 16 )) in the carbocycle have been studied by cyclic voltammetry in MeCN. For 1 – 4 and 7 – 15 , the first reduction peaks have been found to be 1‐electron and reversible, thus corresponding to the formation of their radical anions (RAs), which are long lived at 295 K except those of 4 – 6 and 15 , 16 . Irreversible hydrodechlorination has been observed for 5 and 6 at the first step of their ECR confirmed by EPR detection of corresponding RAs of 2 and 5,7‐H₂ derivative of 1 ( 17 ) at the next steps. Electrochemically generated RAs of 1 – 3 , 7 – 14 , and 17 have been characterized in MeCN by EPR spectroscopy together with DFT calculations at the (U)B3LYP/6‐31 + G(d) level of theory using PCM to describe the solvent. A noticeable alternation of spin density on the –NCCN– moiety of quinoxaline has been observed for all RAs possessing R‐substitution asymmetry. The comparative electron‐accepting ability of 1 – 15 has been analyzed in terms of their experimental reduction peak potentials and the (U)B3LYP/6‐31 + G(d)‐calculated gas‐phase first adiabatic electron affinities (EAs). The differences in electron transfer solvation energies for 1 – 15 have been evaluated on the basis of ECR peaks' potentials and calculated gas‐phase EAs. The ECO of 1 – 5 and 7 – 14 has been found to be irreversible.     

Kinetic Study of the Thermopolymerization of Furfuryl Methacrylate in Bulk by Mathematical Modeling. Part A: Simulation of Experimental Data and Sensitivity Analysis of Kinetic Parameters

Mathematical modeling of the thermopolymerization of FM and CMFMA was carried out using a cross‐linked kinetic model proposed for the photo‐initiated polymerization of acryl‐furanic compounds. In this model, the photochemical initiation step was substituted by a thermal one and it was assumed that the constant of radical termination was time‐dependent, which allowed the gel effect (Trommsdorff) at high monomer conversion to be simulated. Optimization of all kinetic constants was achieved and the results of simulation suitably fitted the experimental data of the monomer conversion. The contribution of each step in the mechanism and its dependence on the experimental conditions were estimated by a sensitivity analysis technique.

     

Magnetodielectric coupling in Ca3Co2O6 triangular Ising lattice

Geometric frustration in magnetic systems is a key ingredient for magnetodielectric coupling. Ca₃Co₂O₆ system is a model of triangular Ising lattice and presenting exotic magnetic properties. With a partially disordered antiferromagnetic ground state and two steps in magnetisation to a ferrimagnetic state and to a ferromagnetic state, this oxide is a good system for studying the effect of frustration in magnetodielectric coupling. Dielectric constant measurements of single crystals of Ca₃Co₂O₆ have been done showing the sensitivity of this technique to frustration.     

Lithium and beryllium hypophosphites

The structures of monoclinic (C2/m) lithium di­hydrogenphosphate, LiH₂PO₂, and tetragonal (P4₁2₁2) beryllium bis(di­hydrogenphosphate), Be(H₂PO₂)₂, have been determined by single‐crystal X‐ray diffraction. The structures consist of layers of hypophosphite anions and metal cations in tetrahedral coordination by O atoms. Within the layers, the anions bridge four Li⁺ and two Be²⁺ cations, respectively. In LiH₂PO₂, the Li atom lies on a twofold axis and the H₂PO₂⁻ anion has the PO₂ atoms on a mirror plane. In Be(H₂PO₂)₂, the Be atom lies on a twofold axis and the H₂PO₂⁻ anion is in a general position.     

Fast chromatographic method for the determination of dyes in beverages by using high performance liquid chromatography—Diode array detection data and second order algorithms

A fast chromatographic methodology is presented for the analysis of three synthetic dyes in non-alcoholic beverages: amaranth (E123), sunset yellow FCF (E110) and tartrazine (E102). Seven soft drinks (purchased from a local supermarket) were homogenized, filtered and injected into the chromatographic system. Second order data were obtained by a rapid LC separation and DAD detection. A comparative study of the performance of two second order algorithms (MCR-ALS and U-PLS/RBL) applied to model the data, is presented. Interestingly, the data present time shift between different chromatograms and cannot be conveniently corrected to determine the above-mentioned dyes in beverage samples. This fact originates the lack of trilinearity that cannot be conveniently pre-processed and can hardly be modelled by using U-PLS/RBL algorithm. On the contrary, MCR-ALS has shown to be an excellent tool for modelling this kind of data allowing to reach acceptable figures of merit. Recovery values ranged between 97% and 105% when analyzing artificial and real samples were indicative of the good performance of the method. In contrast with the complete separation, which consumes 10 mL of methanol and 3 mL of 0.08 mol L⁻¹ ammonium acetate, the proposed fast chromatography method requires only 0.46 mL of methanol and 1.54 mL of 0.08 mol L⁻¹ ammonium acetate. Consequently, analysis time could be reduced up to 14.2% of the necessary time to perform the complete separation allowing saving both solvents and time, which are related to a reduction of both the costs per analysis and environmental impact.     

In vitro photodynamic activity of chloro(5,10,15,20-tetraphenylporphyrinato)indium(III) loaded-poly(lactide-co-glycolide) nanoparticles in LNCaP prostate tumour cells

In(III)-meso-tetraphenylporphyrin (InTPP) was encapsulated into nanoparticles (smaller than 200 nm) of poly(d,l-lactide-co-glycolide) (PLGA) using the emulsification–evaporation technique. The photodynamic efficacy of InTPP-loaded nanoparticles and its cellular uptake was investigated with LNCaP prostate tumour cells, in comparison with the free InTPP. The effects of incubation time (1–3 h), drug concentration (1.8–7.7 μmol/L) and incident light dose (15–45 J/cm²) with both encapsulated and free InTPP were studied. The type of cell death induced by the photochemical process using both encapsulated and free InTPP was also investigated. Cell viability was reduced more significantly with increasing values of these effects for InTPP-loaded nanoparticles than with the free drug. The cellular death induced by both encapsulated and free InTPP was preponderantly apoptotic. Confocal laser scanning microscopy data showed that the InTPP-loaded nanoparticles, as well free InTPP, were localized in the cells, and always in the perinuclear region. Encapsulated InTPP was measured by the intensity of fluorescence intensity of cell extracts and was three times more internalized into the cells than was the free InTPP. Electron paramagnetic resonance experiments corroborated the participation of singlet oxygen in the photocytotoxic effect of nanoparticles loaded with InTPP.     

On-line ionic imprinted polymer selective solid-phase extraction of nickel and lead from seawater and their determination by inductively coupled plasma-optical emission spectrometry

Nickel(II) and lead(II) ionic imprinted 8-hydroxyquinoline polymers were synthesized by a precipitation polymerization technique and were used as selective solid phase extraction supports for the determination of nickel and lead in seawater by flow injection solid phase extraction on-line inductively coupled plasma-optical emission spectrometry. An optimum loading flow rate of 2.25 mL min⁻¹ for 2 min and an elution flow rate of 2.25 mL min⁻¹ for 1 min gave an enrichment factor of 15 for nickel. However, a low dynamic capacity and/or rate for adsorption and desorption was found for lead ionic imprinted polymer and a flow rate of 3.00 mL min⁻¹ for 4-min loading and a flow rate of 2.25 mL min⁻¹ for 1-min elution gave a enrichment factor of 5. The limit of detection was 0.33 μg L⁻¹ for nickel and 1.88 μg L⁻¹ for lead, with a precision (n = 11) of 8% (2.37 μg Ni L⁻¹) for nickel and 11% (8.38 μg Pb L⁻¹) for lead. Accuracy was also assessed by analyzing SLEW-3 (estuarine water) and TM-24 (lake water) certified reference materials, and the values determined were in good agreement with the certified concentrations.     

Application of a Viscoelastic Model to simulate the Interface of a Metal/Fibre-Reinforced Polymer Joint

A viscoelastic model with the Lemaitre-type damage is applied to simulate an interfacial adhesive zone in light weight engineering structures, like aluminum/fiber-reinforced polymer specimens. The evolution of irreversible deformation and damage progression are investigated. The joint of aluminium alloy 5754 (AA5754) and carbon fibre reinforced thermoplastic composite CF-PA66 is manufactured by means of an epoxy (1K) adhesive. The adhesive zone is considered as an interface material. The aim of the research is to study the influence of the interface geometry on the mechanical characteristics of the structure. (© 2011 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim)