Ferulic Acid: A Natural Phenol That Inhibits Neoplastic Events through Modulation of Oncogenic Signaling

Despite the immense therapeutic advances in the field of health sciences, cancer is still to be found among the global leading causes of morbidity and mortality. Ethnomedicinally, natural bioactive compounds isolated from various plant sources have been used for the treatment of several cancer types and have gained notable attention. Ferulic acid, a natural compound derived from various seeds, nuts, leaves, and fruits, exhibits a variety of pharmacological effects in cancer, including its proapoptotic, cell-cycle-arresting, anti-metastatic, and anti-inflammatory activities. This review study presents a thorough overview of the molecular targets and cellular signaling pathways modulated by ferulic acid in diverse malignancies, showing high potential for this phenolic acid to be developed as a candidate agent for novel anticancer therapeutics. In addition, current investigations to develop promising synergistic formulations are also discussed.     

Benzimidazole‐based silver(I)–N‐heterocyclic carbene complexes as anti‐bacterials: synthesis,crystal structures and nucleic acids interaction studies

A series of new benzimidazolium salts as N‐heterocyclic carbene (NHC) precursors has been synthesized. Reactions of these salts with Ag₂O with varying metal‐to‐salt ratio facilitate the formation of a series of new binuclear and mononuclear Ag(I)–NHC complexes. All compounds were characterized using physicochemical and spectroscopic techniques. Single‐crystal X‐ray diffraction study reveals a binuclear structure for one of the complexes and a mononuclear one for two others. These complexes exist as cationic Ag(I)–NHC complexes with the chelation of carbene carbons to the silver centre in an almost linear manner. The compounds were screened for their anti‐bacterial activities against Staphylococcus aureus (ATCC 12600) as a Gram‐positive bacterium and Escherichia coli (ATCC 25922) as a Gram‐negative bacterium. The results show that both bacteria appear markedly inhibited. Furthermore, the results suggest the possibility of steric variation as a modulation of the anti‐bacterial activities. The nuclease activities of the compounds were assessed using gel electrophoresis and the results indicate that these complexes can cleave or degrade DNA and RNA via a non‐oxidative mechanism. Copyright © 2014 John Wiley & Sons, Ltd.     

The synergistic effect between graphene oxide nanocolloids and silicon dioxide nanoparticles for gallic acid sensing

For the first time, the synergistic effect of graphene oxide nanocolloids (nano-GO) and silicon dioxide (silica) nanoparticles (SiO₂-nanoparicles) has been used to modify a glassy carbon electrode (GCE) for the determination of gallic acid (GA). The modified electrode surface was characterised by using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDXA) and Fourier transform infrared spectroscopy (FTIR). The electrochemical behaviour of the modified electrode was then studied, using cyclic voltammetry (CV) and differential pulse voltammetry (DPV), showing that the electrode was sensitive to GA in a concentration range of 6.25 × 10⁻⁶ to 1.0 × 10⁻³ mol L⁻¹, with a correlation coefficient R² of 0.9956 and a limit of detection of 2.09 × 10⁻⁶ mol L⁻¹ (S/N = 3). The proposed method was successfully used for the determination of GA in red wine, white wine and orange juice, with recoveries of 102.3, 95.4 and 97.6%, respectively.

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Chemical demulsification of natural petroleum emulsions of Assam (India)

About one third petroleum production of every oil field is in the form of water in oil emulsions which are normally stabilized by the nickel and vanadium porphyrins from asphaltene portion of crude. The petroleum emulsions of Assam oil fields which have been taken for the present work, are stabilized by the organometallic compounds of iron and high molecular weight compounds from asphaltenes. There is least possibility of any change on these natural petroleum emulsions. The Assam oil field emulsions have been tried to be broken by polyoxyethylene alkyl phenols, their sulphonates and sodium sulphonates in different combinations. The nonyl and octyl phenols with 30 and 40 molecules of ethylene oxide are found most suitable demulsifiers for Lakwa, Rudrasagar and Galeki (Assam) oil fields emulsions. The effect of polyoxyethylene alkyl phenols followed by the treatment of polyvalent cations had been studied for the first time in the field of demulsification of natural petroleum emulsions. This new combination has shown the best results as this broke even the most stable petroleum emulsions which could not be broken by polyoxyethylene alkyl phenols alone. In the present paper a simple method for calculating the chemical demulsification efficiency and a factor H/S paralleled to HLB & H/L for evaluating the emulsification property of surface active agents, have been introduced.     

Solid film versus solution-phase charge-recombination dynamics of exTTF-bridge-C60 dyads

The charge-recombination dynamics of two exTTF-C60 dyads (exTTF = 9,10-bis(1,3-dithiol-2-ylidene)-9,10-dihydroanthracene), observed after photoinduced charge separation, are compared in solution and in the solid state. The dyads differ only in the degree of conjugation of the bridge between the donor (exTTF) and the acceptor (C60) moieties. In solution, photoexcitation of the nonconjugated dyad C60-BN-exTTF (1) (BN = 1,1'-binaphthyl) shows slower charge-recombination dynamics compared with the conjugated dyad C60-TVB-exTTF (2) (TVB = bisthienylvinylenebenzene) (lifetimes of 24 and 0.6 micros, respectively), consistent with the expected stronger electronic coupling in the conjugated dyad. However, in solid films, the dynamics are remarkably different, with dyad 2 showing slower recombination dynamics than 1. For dyad 1, recombination dynamics for the solid films are observed to be tenfold faster than in solution, with this acceleration attributed to enhanced electronic coupling between the geminate radical pair in the solid film. In contrast, for dyad 2, the recombination dynamics in the solid film exhibit a lifetime of 7 micros, tenfold slower than that observed for this dyad in solution. These slow recombination dynamics are assigned to the dissociation of the initially formed geminate radical pair to free carriers. Subsequent trapping of the free carriers at film defects results in the observed slow recombination dynamics. It is thus apparent that consideration of solution-phase recombination data is of only limited value in predicting the solid-film behaviour. These results are discussed with reference to the development of organic solar cells based upon molecular donor-acceptor structures.     

Extraction spectrophotometric method for the determination of ascorbic acid in pharmaceutical preparations, urine and fruit juices with potassium iodate

An indirect determination of ascorbic acid is based on extraction of the iodine produced by reduction of potassium iodate. Beer's law is obeyed over the range 0.02-0.36 mg/ml ascorbic acid.     

A supramolecular approach to lithium ion solvation at nanostructured dye sensitised inorganic/organic heterojunctions

A novel arylamine based hole transporting material (HTM) with tetraethylene glycol (TEG) side groups is reported. Lithium ions solubilised by the TEG groups are employed to modulate interfacial electron transfer reactions at a dye sensitised TiO2/HTM interface.     

Slow charge recombination in dye-sensitised solar cells (DSSC) using Al2O3 coated nanoporous TiO2 films

The conformal growth of an overlayer of Al2O3 on a nanocrystalline TiO2 film is shown to result in a 4-fold retardation of interfacial charge recombination, and a 30% improvement in photovoltaic device efficiency.     

N-arylation of primary and secondary aliphatic amines on solid supports

A general and mild method for the N-arylation of primary and secondary aliphatic amines is reported. Copper acetate, triethylamine mediated C/N cross-coupling reaction of arylboronic acids at room temperature to solid-supported primary and secondary amines gave good to excellent yields of the desired N-arylated products.     

Transient absorption studies and numerical modeling of iodine photoreduction by nanocrystalline TiO2 films

We have used transient absorption spectroscopy to study the reaction between photogenerated electrons in a dye-free nanocrystalline titanium dioxide film and an iodine/iodide redox couple. Recombination kinetics was measured by recording the transient optical signal following band gap excitation by a UV laser pulse. In the presence of a methanol hole scavenger in the electrolyte, a long-lived (0.1-1 s) red/infrared absorbance is observed and assigned to photogenerated electrons forming Ti(3+) species. In the presence of iodine and excess iodide in the electrolyte, the signal decays on a millisecond-microsecond time scale, assigned to reduction of the redox couple by photogenerated electrons in the TiO(2). The electron lifetime decreases inversely with increasing iodine concentration, indicating that the back reaction is first order in [I(2)]. No evidence for I(2)(-) is observed, indicating that the reaction mechanism does not involve the formation of I(2)(-) as an intermediate. The shape of the kinetics evolves from monoexponential at low [I(2)] to stretched-exponential as [I(2)] increases. A Monte Carlo continuous-time random walk model is implemented to simulate the kinetics and its [I(2)] dependence and used to address the order of the recombination reaction with respect to electron density, n. The model incorporates the diffusion of oxidized species from the electrolyte toward the TiO(2) surface as well as electron trapping and transport in the TiO(2). In the limit of low [I(2)], the monoexponential kinetics is explained by the recombination reaction being rate limited by the diffusion of the oxidized species in the electrolyte. The stretched-exponential behavior at high [I(2)] can be explained by the reaction being rate limited by the transport of electrons through a distribution of trap states toward reactive sites at the TiO(2)-electrolyte interface, similar to the mechanism proposed previously for the kinetics of electron-dye cation recombination. Such trap-limited recombination can also explain the superlinear dependence of electron recombination rate on electron density, which has been reported elsewhere, without the need for a reaction mechanism that is second order in n. In contrast, a second-order reaction mechanism in a trap-free medium cannot explain the observed kinetics, although a second-order mechanism incorporating electron trapping cannot be conclusively ruled out by the data. We propose that the most likely reaction scheme, that is first order in both [I(2)] and n, is the dissociative reduction of I(2) onto the metal oxide surface, followed by a second electron reduction of the resulting adsorbed iodine radical, and that empirical second-order behavior of the electron lifetime is most likely explained by electron trapping rather than by a second-order recombination mechanism.