Deoxygenation of some α-dicarbonyl compounds by tris(diethylamino)phosphine in the presence of fullerene C60

The reactions of such cyclic α-diketones as acenaphthenequinone, aceanthrenequinone, and N-alkylisatins, with hexaethyltriaminophosphine in the presence of the fullerene C(60), lead to the formation of methanofullerene derivatives under mild conditions. This process proceeds via deoxygenation of the dicarbonyl compound by the P(III) derivative and is likely to involve the intermediate formation of α-ketocarbenes. The structure of some methanofullerenes has been confirmed by NMR and XRD. The electrochemical behavior of the methanofullerenes was also investigated.     

Reactions of functionally substituted bicyclo[4.2.2]deca-2,4,7,9-tetraenes with m-chloroperbenzoic acid and in vitro evaluation Of Product Cytotoxicity against tumor cells

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Structure and supramolecular organization of tri-n-butyl(octadecyl)phosphonium tetrafluoroborate and its influence on catalytic activity of stabilized palladium nanoparticles

Russian Chemical Bulletin - A crystal structure and aggregation properties of tri-n-butyl(octadecyl)phosphonium tetrafluoroborate were studied. Palladium nanoparticles stabilized by this...     

Scaled in Cartesian Coordinates Ab Initio Molecular Force Fields of DNA Bases: Application to Canonical Pairs

The model of Regularized Quantum Mechanical Force Field (RQMFF) was applied to the joint treatment of ab initio and experimental vibrational data of the four primary nucleobases using a new algorithm based on the scaling procedure in Cartesian coordinates. The matrix of scaling factors in Cartesian coordinates for the considered molecules includes diagonal elements for all atoms of the molecule and off-diagonal elements for bonded atoms and for some non-bonded atoms (1–3 and some 1–4 interactions). The choice of the model is based on the results of the second-order perturbation analysis of the Fock matrix for uncoupled interactions using the Natural Bond Orbital (NBO) analysis. The scaling factors obtained within this model as a result of solving the inverse problem (regularized Cartesian scale factors) of adenine, cytosine, guanine, and thymine molecules were used to correct the Hessians of the canonical base pairs: adenine–thymine and cytosine–guanine. The proposed procedure is based on the block structure of the scaling matrix for molecular entities with non-covalent interactions, as in the case of DNA base pairs. It allows avoiding introducing internal coordinates (or coordinates of symmetry, local symmetry, etc.) when scaling the force field of a compound of a complex structure with non-covalent H-bonds.     

Sereoselective Addition of Benzaldehyde N,N-Dimethyl-Hydrazone to 2-RfO-4-Oxo-5,6-Benzo-1,3,2-Dioxaphosphorinanes. The Spatial Structure of 2-Pentafluorophenoxy-4-Dimethylamino-2,5-Dioxo-3-Phenyl-6,7-Benzo-1,4,2-Oxazaphosphepine

Abstract

[3+2]-Cycloaddition of N,N-dimethylhydrazone benzaldehyde (I) to 2-R_FO-4-oxo-5,6-benzo-l,3,2-dioxaphosphorinanes (II) yields the new heterocycle - 2-R_FO-4-Me₂N-2,5-dioxo-3-phenyl-6,7-benzo- 1,4,2-dioxaphosphepine (III) [R_F = C₆F₅, CH(CF₃)₂) with high stereoselectivity (above 94%). The reaction is likely to involve the initial interaction of nitrogen as a nucleophile with wbonyl carbon as an electrophile. The hydrolysis of (III) leads to phosphonic acid (IV) (OR_F = OH).     

Supramolecular Tools to Improve Wound Healing and Antioxidant Properties of Abietic Acid: Biocompatible Microemulsions and Emulgels

Abietic acid, a naturally occurring fir resin compound, that exhibits anti-inflammatory and wound-healing properties, was formulated into biocompatible emulgels based on stable microemulsions with the addition of a carbamate-containing surfactant and Carbopol^® 940 gel. Various microemulsion and emulgel formulations were tested for antioxidant and wound-healing properties. The chemiluminescence method has shown that all compositions containing abietic acid have a high antioxidant activity. Using Strat-M^® skin-modelling membrane, it was found out that emulgels significantly prolong the release of abietic acid. On Wistar rats, it was shown that microemulsions and emulgels containing 0.5% wt. of abietic acid promote the rapid healing of an incised wound and twofold tissue reinforcement compared to the untreated group, as documented by tensiometric wound suture-rupture assay. The high healing-efficiency is associated with a combination of antibacterial activity of the formulation components and the anti-inflammatory action of abietic acid.     

Application of surface plasmon resonance for the detection of carbohydrates,glycoconjugates, and measurement of the carbohydrate-specific interactions: A comparison with conventional analytical techniques. A critical review

Carbohydrates (glycans) and their conjugates with proteins and lipids contribute significantly to many biological processes. That makes these compounds important targets to be detected, monitored and identified. The identification of the carbohydrate content in their conjugates with proteins and lipids (glycoforms) is often a challenging task. Most of the conventional instrumental analytical techniques are time-consuming and require tedious sample pretreatment and utilising various labeling agents. Surface plasmon resonance (SPR) has been intensively developed during last two decades and has received the increasing attention for different applications, from the real-time monitoring of affinity bindings to biosensors. SPR does not require any labels and is capable of direct measurement of biospecific interaction occurring on the sensing surface. This review provides a critical comparison of modern analytical instrumental techniques with SPR in terms of their analytical capabilities to detect carbohydrates, their conjugates with proteins and lipids and to study the carbohydrate-specific bindings. A few selected examples of the SPR approaches developed during 2004–2011 for the biosensing of glycoforms and for glycan–protein affinity studies are comprehensively discussed.     

Encapsulation of quantum dots in supramolecular systems based on amphiphilic compounds and polyelectrolytes

Supramolecular nanocontainers based on monocationic and gemini surfactants and oppositely charged polyelectrolytes (polyacrylic acid, polyethyleneimine) for the stabilization and enhancement of solubility of hydrophobic quantum dots CdSe/ZnS were formed. The size (from 2 to 70 nm depending on the type of nanocontainers) and shape of aggregates containing quantum dots were determined by transmission electron microscopy. It was shown that the nature of the stabilizing agent influences the morphology of aggregates. The increase in photostability of quantum dots in micellar solutions of gemini surfactants and the possibility of their preservation in the polyelectrolyte capsules are identified.