Development of a caffeic acid-phthalimide hybrid compound for NADPH oxidase inhibition.

NADPH oxidases are pharmacological targets for the treatment of inflammation-based diseases. This work presents the synthesis and study of a caffeic acid/phthalimide hybrid compound (C2) as a potential inhibitor of NADPH oxidases. Throughout the study, we have compared compound C2 with its precursor caffeic acid (C1).

Combined Spectroscopic and TD-DFT Analysis to Elucidate Substituent and Acidochromic Effects in Organic Dyes: A Case Study on Amino- versus Nitro-Substituted 2,4-Diphenylquinolines.

A combined spectroscopic and TD-DFT case study was performed, to identify a robust method to calculate the complex near UV/Vis absorption spectra of various amino- vs. nitro-substituted 2,4-diphenylquinolines, which vary strongly under neutral and successively acidic conditions. For this, different DFT functionals were tested for geometry optimization and the TD part to calculate the neutral and different protonated species in a fast screening approach, i.

Designing new quinoline-based organic photosensitizers for dye-sensitized solar cells (DSSC): a theoretical investigation.

In this work, 27 new quinoline-derivative dyes were proposed, and their geometries, electronic structures, and absorption spectra were investigated using density functional theory (DFT) calculations. An important feature found in most of the new compounds was that the lowest unoccupied molecular orbital (LUMO) was above the TiO conduction band, facilitating electron transfer from the excited dye to the semiconductor. The energy of the highest occupied molecular orbital (HOMO) was below the reduction potential energy of the electrolyte (I/I), improving the charge regeneration process after photooxidation.

Induction of axial chirality in divanillin by interaction with bovine serum albumin.

Vanillin is a plant secondary metabolite and has numerous beneficial health applications. Divanillin is the homodimer of vanillin and used as a taste enhancer compound and also a promissory anticancer drug. Here, divanillin was synthesized and studied in the context of its interaction with bovine serum albumin (BSA).

Theoretical-Experimental Photophysical Investigations of the Solvent Effect on the Properties of Green- and Blue-Light-Emitting Quinoline Derivatives.

This paper describes the investigations on the solvatochromic effect and the photophysical properties of quinoline derivatives, compounds with potential applicability in optoelectronic devices. Using an experimental and theoretical approach, the effect of the solvent and the insertion of the phenyl, nitro, amino and dimethylamino group in the quinoline backbone were investigated. The use of Density Functional Theory (DFT) calculations provided the bases for the understanding of the energetic transitions observed in the absorption and fluorescence experiments.

NbCl -Promoted Synthesis of Fluorescein Dye Derivatives: Spectroscopic and Spectrometric Characterization and Their Application in Dye-Sensitized Solar Cells.

Fluorescein has several applications owing to its properties, such as high molar absorptivity, high fluorescence quantum yield, high photostability, and wavelengths of absorption and emission in the visible region. The syntheses of fluorescein derivatives between phenol and anhydride derivatives by using NbCl as a Lewis acid is described. The products have high yields and short reaction times are observed.

Facile Synthesis and Photophysical Characterization of New Quinoline Dyes.

This paper describes the synthesis of new quinoline derivatives, molecules that has been long interest in the organic and medicinal chemistry. Through the Multicomponent Reaction (MCR), an important tool in modern synthetic methodology, that generate products with good structural complexity, in addition to economy of atoms and selectivity, we provide easy access to the preparation of quinoline derivatives. The reactions were promoted by niobium pentachloride, as a Lewis acid.

Synthesis, Antioxidant and Anti-inflammatory Properties of an Apocynin- Derived Dihydrocoumarin.

Background: Coumarin derivatives as dihydrocoumarins have been reported to have multiple biological activities, such as antioxidant and anti-inflammatory properties. Apocynin (APO), which is a substituted-methoxy-catechol, is the most commonly used inhibitor of the multienzymatic complex NADPH-oxidase.

Objective: To increase the potency of APO as an NADPH oxidase inhibitor and its antioxidant and anti-inflammatory activities, we synthesized a compound by combining the structural features of a dihydrocoumarin and APO.

Polybioside, a neuroactive compound from the venom of the social wasp Polybia paulista.

Polybioside (1) was isolated from the venom of the social wasp Polybia paulista, and its structure was assigned as 3,4,5-trihydroxy-6-(hydroxymethyl)tetrahydro-2H-pyran-2-yl 3-(1H-imidazol-4-yl)propanimidate by NMR and MS protocols. The application of polybioside in rat brain, followed by the detection of c-Fos protein expression in some brain regions, indicated the compound is neuroactive in a number of brain areas. Polybioside causes convulsions in rats, even when peripherally applied.

Monoamine oxidase inhibitory activities of indolylalkaloid toxins from the venom of the colonial spider Parawixia bistriata: functional characterization of PwTX-I.

Colonial spiders evolved a differential prey-capture behaviour in concert with their venom chemistry, which may be a source of novel drugs. Some highly active tetrahydro-beta-carboline (THbetaC) toxins were recently isolated from the venom of the colonial spider Parawixia bistriata; the spiders use these toxins as part of their chemical arsenal to kill and/or paralyze preys. The major THbetaC compound isolated from this venom was identified as 6-hydroxytrypargine, also known as PwTX-I.

Evaluation of the aggressive potential of marine chloride and sulfate salts on mortars applied as renders in the Metropolitan Region of Salvador--Bahia, Brazil.

In recent years, growing interest has focused on determining the performance of materials and evaluating the service life of structures exposed to various environmental forces. In this context, the determination of the aggressive potential of marine salts on mortars used as external renders is critical. The present study aimed to evaluate the spatial distribution of marine salts relative to distance from the sea.

High stereoselectivity on low temperature Diels-Alder reactions.

We have found that some of the usually poor dienophiles (2-cycloenones) can undergo Diels-Alder reaction at -78 degrees C with unusually high stereoselectivity in the presence of niobium pentachloride as a Lewis acid catalyst. A remarkable difference in reaction rates for unsubstituted and alpha- or beta-methyl substituted 2-cycloenones was also observed.

Structural assignment of Diels-Alder adducts: an experimental and theoretical approach.

A detailed NMR analysis with total assignment of (1)H and (13)C NMR data for the endo and the exo adducts, obtained by Diels-Alder reaction between 2-cyclohexenone and cyclopentadiene, is described. The unequivocal assignment of the endo and exo structures was performed by (1)H and (13)C NMR. These assignments were supported by theoretical chemical shift calculations at GIAO/HF level using 6-311 + g(2d, p) from optimized structures at the B3LYP/6-31g(d) level.