The preparation and characterization of a novel pillar[5]arene based supramolecular system with mesalazine, a prescribed aminosalicylate drug was successfully achieved. Pyridinium-pillar[5]arene was efficiently prepared in three steps from hydroquinone bis(2-hydroxyethyl) ether derivative in high yield. It was demonstrated that the association between the compounds is pH dependent with an association constant of 3.4 × 103 L mol-1 near physiological conditions, leading to quenching of the fluorescence emission of mesalazine in the presence of the cationic macrocycle. Theoretical calculations indicate that the association between both molecules is of electrostatic nature. Formation of aggregates was also demonstrated in low concentrations of pillar[5]arene that is related to the non-linear behavior of the Stern-Volmer plot for quenching of mesalazine fluorescence emission.

In this study, for the first time, histamine-functionalized magnetic nanoparticles (HIS-MNP) were used as sorbent phase combined with bar adsorptive microextraction (BAµE) for the determination of methylparaben (MP), ethylparaben (EP), propylparaben (PP), and butylparaben (BP) in water samples by high performance liquid chromatography coupled with diode array detection (HPLC-DAD). Extraction and desorption conditions, including desorption time and solvent, ionic strength effect and extraction time, were investigated. The extractions were performed for 90 min, 30% of NaCl and sample pH 5. Desorption was carried out using 250 μL of acetonitrile:methanol (25:75 v/v) for 30 min. The limits of detection (LODs) were of 1.5 μg L-1 and limits of quantification (LOQs) were 5.0 μg L-1 for all analytes. The intra-day precision ranged from 1% for EP, PP and BP to 3% for MP, EP, PP and BP. The inter-day precision ranged from 3% for EP to 18% for BP. The relative recoveries varied from 81 to 125%, and relative standard deviations (RSD) ranged between 1 and 16%.

Abstract Species distribution mapping methods have their advantages and limitations concerning their use on theoretical and/or applied macroecological approaches. However, it remains underexplored how the estimates of community ecology metrics vary across the distributions generated by different mapping methods. Here, we mapped the distribution patterns of the anuran beta diversity in the Atlantic Forest and Cerrado hotspots generated by three mapping methods: point-to-grid (PTG), extent-of-occurrence (EOO), and ecological niche modelling (ENM) maps, so we were able to compare the congruence of the local contribution to beta diversity index (LCBD) among them, as well as their turnover and nestedness components. PTGs generated the most divergent LCBD values probably due to the more resolved spatial scale in which species’ presence are considered, so EEO and ENM generated similar beta diversity estimates for both hotspots. High LCBD values in the Cerrado were recorded in ecotone regions, whereas in the Atlantic Forest the highest beta diversity values were found along the Atlantic coast. The structure of beta diversity of PTG showed way too high values of importance for the turnover component compared to the EEO and ENM maps, which also recorded higher importance for the turnover than for the nestedness component.

Este trabalho descreve a preparação de ésteres e amidas derivados do ácido caurenóico e a avaliação da atividade antifúngica frente a cepas padronizadas de fungos patogênicos. Ésteres alquílicos e benzílicos foram obtidos com bons rendimentos, sob condições brandas, a partir da esterificação do ácido caurenóico com haletos de alquila em KOH-acetona. Todos os compostos sintetizados foram submetidos aos testes de inibição contra leveduras, hifomicetos e dermatófitos, mas somente o ácido caurenóico e os derivados contendo um grupo carboxilato livre apresentaram atividade moderada frente a dermatófitos.

Representative esters derived from kaurenoic acid were prepared in order to evaluate their antifungal properties. Alkyl and substituted benzyl esters were obtained in good yield under mild conditions by esterification of kaurenoic acid with the corresponding alkyl halide in KOH-acetone. All synthesized compounds were tested for antifungal properties against pathogenic yeasts, hialohyphomycetes and dermatophytes. Kaurenoic acid and derivatives containing a free carboxyl group were moderately active against dermatophytes.