Evaluation of the enantioselective binding of imazalil to human serum albumin by capillary electrophoresis

In this work, a methodology for the evaluation of enantioselective binding of imazalil (IMA) enantiomers to human serum albumin (HSA) that does not require the separation of free and bound to HSA fractions is developed. This methodology comprises the incubation of IMA–HSA designed mixtures for 30 min directly in the capillary electrophoresis system and the subsequent direct injection and chiral separation of IMA employing highly sulfated β‐cyclodextrin as chiral selector and the complete filling technique. Two mathematical approaches were used to estimate apparent affinity constants (K₁), protein binding and enantioselectivity (ES) for both enantiomers of IMA. Moderate enantioselective binding of IMA enantiomers to HSA (ES = 2.0) was shown by the 1:1 stoichiometry and log K₁ values of 3.4 ± 0.4 and 3.1 ± 0.3 for the first and second eluted enantiomers, respectively. Copyright © 2015 John Wiley & Sons, Ltd.     

A Chemogenetic Approach for the Optical Monitoring of Voltage in Neurons

Optical monitoring of neuronal voltage using fluorescent indicators is a powerful approach for the interrogation of the cellular and molecular logic of the nervous system. Herein, a semisynthetic tethered voltage indicator (STeVI1) based upon nile red is described that displays voltage sensitivity when genetically targeted to neuronal membranes. This environmentally sensitive probe allows for wash‐free imaging and faithfully detects supra‐ and sub‐threshold activity in neurons.     

Bignoniaceae metabolites as semiochemicals

Members of the family Bignoniaceae are mostly found in tropical and neo-tropical regions in America, Asia and Africa, although some of them are cultivated in other regions as ornamentals. Species belonging to this family have been extensively studied in regard to their pharmacological properties (as extracts and isolated compounds). The aim of this review is to summarize the reported scientific evidence about the chemical properties as well as that of the extracts and isolated compounds from species of this family, focusing mainly in insect-plant interactions. As it is known, this family is recognized for the presence of iridoids which are markers of oviposition and feeding preference to species which have became specialist feeders. Some herbivore species have also evolved to the point of been able to sequester iridoids and use them as defenses against their predators. However, iridoids also exhibit anti-insect properties, and therefore they may be good lead molecules to develop botanical pesticides. Other secondary metabolites, such as quinones, and whole extracts have also shown potential as anti-insect agents.     

Theoretical Characterization of Charge Transport in One‐Dimensional Collinear Arrays of Organic Conjugated Molecules

A great deal of interest has recently focused on host–guest systems consisting of one‐dimensional collinear arrays of conjugated molecules encapsulated in the channels of organic or inorganic matrices. Such architectures allow for controlled charge and energy migration processes between the interacting guest molecules and are thus attractive in the field of organic electronics. In this context, we characterize here at a quantum‐chemical level the molecular parameters governing charge transport in the hopping regime in 1D arrays built with different types of molecules. We investigate the influence of several parameters (such as the symmetry of the molecule, the presence of terminal substituents, and the molecular size) and define on that basis the molecular features required to maximize the charge carrier mobility within the channels. In particular, we demonstrate that a strong localization of the molecular orbitals in push–pull compounds is generally detrimental to the charge transport properties.     

Sensitive determination of indomethacin in pharmaceuticals and urine by sequential injection analysis and optosensing

A selective and sensitive method based on coupling of sequential injection analysis (SIA) and optosensing was developed and applied to the determination of indomethacin in pharmaceutical and urinary samples. After alkaline hydrolysis, the fluorescent product generated from indomethacin is inserted in the flow system, transitorily retained on an active solid support (Sephadex QAE A-25) filling the flowcell, and monitored at 283/371 nm (lamda ex / lamda em). The system was calibrated for two sample volumes, 100 and 1000 microL. It showed a linear dynamic range of 0.5-6.5 ng/mL, with an LOD of 0.15 ng/mL and an RSD of 3.9% (n=10) when the highest sample volume was used. The proposed fluorometric SIA optosensor was applied to the determination of indomethacin in both pharmaceuticals and urine samples, and satisfactory results were obtained.     

Anionic rare-earth thiocyanate complexes as building blocks for low-melting metal-containing ionic liquids

The first examples of ionic liquids with rare-earth-containing anions are presented. These ionic liquids based on rare-earth thiocyanate complexes are liquid at room temperature, despite the multivalent character of the anionic building blocks.     

An algebraic interpretation of the <Emphasis Type="Italic">q</Emphasis>-Meixner polynomials

An algebraic interpretation of the q-Meixner polynomials is obtained. It is based on representations of \({\mathscr {U}}_q({\mathfrak {su}}(1,1))\) on q-oscillator states with the polynomials appearing as matrix elements of unitary q-pseudorotation operators. These operators are built from q-exponentials of the \({\mathscr {U}}_q({\mathfrak {su}}(1,1))\) generators. The orthogonality, recurrence relation, difference equation, and other properties of the q-Meixner polynomials are systematically obtained in the proposed framework.     

Fractional parts of dense additive subgroups of real numbers

Given a dense additive subgroup G of \(\mathbb {R}\) containing \(\mathbb {Z}\), we consider its intersection \(\mathbb {G}\) with the interval [0, 1[ with the induced order and the group structure given by addition modulo 1. We axiomatize the theory of \(\mathbb {G}\) and show it is model-complete, using a Feferman-Vaught type argument. We show that any sufficiently saturated model decomposes into a product of a standard part and two ordered semigroups of infinitely small and infinitely large elements.