Medicinal Chemistry is a multidisciplinary discipline and the discovery of new bioactive molecules is one of its objectives. Molecular Hybridization (MH) is a strategy of rational design of new prototypes, where the lead compound is produced through an adequate fusion of pharmacophoric sub-unities. Undergraduate laboratory experiments for Medicinal Chemistry education with a focus on MH are scarce. Therefore, the present paper describes a practice class for some undergraduate courses (Pharmacy, Chemistry and/or Chemical Engineering) involving drug development and MH that can be performed at low cost. In this work, alternative materials such as paracetamol and sulfadiazine tablets were used to engage student's attention and to contextualize important concepts of MH. The experiment describes the synthesis of a new compound involving the azo coupling between an aromatic amine (sulfadiazine) and a phenol (paracetamol) to show undergraduate students a practical example of MH. In this case, SciFinder ® - a search website of the American Chemical Society - was also demonstrated and utilized as a search tool in the proposed experimental class. ]]>

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Recebido em 26/9/12; aceito em 26/3/13; publicado na web em 14/5/13 CONTEXTUALIZING ACID-BASE REACTIONS ACCORDING TO BRÖNSTED-LOWRY PROTONIC THEORY USING PROPRANOLOL AND NIMESULIDE TABLETS. This paper reports the use of alternative materials for teaching experimental chemistry. In this context, nimesulide and propranolol tablets were used to teach chemical concepts about acid-base reactions according to Brönsted-Lowry protonic Theory. Important topics of Organic, Analytical and Pharmaceutical Chemistry were discussed, such as purification by acid-base extraction, solubility of organic compounds in aqueous solutions, buffers, the dissociation constant (pK a ), potentiometric titration and ionization of drugs in biological fluids. The purification of propranolol and nimesulide from tablets produced yields of 75% and 90%, respectively. The experimental values of pK a for both drugs were in agreement with those from the literature.

RESUMO Objetivo: verificar a ocorrência e o tipo mais frequente de alteração auditiva em crianças expostas a toxoplasmose durante a gestação. Métodos: estudo retrospectivo longitudinal realizado em instituição pública de saúde de São Paulo. Análise de prontuários de crianças nascidas entre 2010 e 2015 distribuídos em dois grupos: grupo estudo, composto por 48 crianças de mães com diagnóstico de toxoplasmose durante a gestação; e grupo controle, composto por 43 crianças sem infecção congênita que foram acompanhadas por apresentar baixo peso ao nascimento. As crianças foram avaliadas de duas a quatro vezes durante os dois primeiros anos de vida, por meio de testes que avaliam a função auditiva periférica e central. Resultados: 47 crianças fizeram apenas duas avaliações e apenas 11 completaram todas as avaliações até 24 meses. No grupo controle 58,1% apresentaram audição normal, 37,2% perda condutiva, 4,7% perda coclear e ausência de alteração retrococlear, enquanto o grupo estudo apresentou 56,3% de audição normal, 20,8% de perda condutiva, 2,1% de perda coclear e 20,8% de alteração retrococlear. Conclusão: crianças expostas à toxoplasmose durante a gestação não diferiram das não expostas em relação à ocorrência de perda auditiva coclear e condutiva. Entretanto, apresentaram maior ocorrência de alteração retrococlear.

There are still no valid, clinically feasible instruments to assess backward masking (BM), an auditory temporal processing (ATP) phenomenon. The aim of this study was to develop, standardize and present evidence of validity for a behavioral test for BM assessment. Young adults were submitted to a BM test (BMT), where they were asked to identify a 1000 Hz pure tone followed by a narrowband noise with interstimulus intervals of 0 to 400 ms and signal-to-noise ratio (SNR) between −20 and −30 dB. The correct response rate and target sound detection threshold were calculated, and the results compared with those of young adults with abnormal ATP tests and older adults. Diagnostic accuracy analyses were carried out. Young adults with normal ATP obtained an average correct response rate of 89 and 87% for SNR −20 and −30 dB, respectively, with average thresholds between 10 and 15 ms and no difference between the left and right ears. Results were more consistent at SNR −20 dB, and the best diagnostic accuracy was obtained for SNR −20 dB, with good specificity, but low sensitivity. Normative values were obtained for the BMT, which proved to be clinically feasible, with preliminary evidence of validity.

The Masking Level Difference (MLD) test is one of the main instruments for investigating binaural interaction. Studies with children aged 7–12 years still disagree about the influence of age on test performance and present discordant reference values. This study aimed to verify the effect of age on the performance of children aged 7–12 years in the MLD test and to establish reference values and cutoff criteria for this age group. Fifty-nine children with normal hearing were organized in three groups according to their age: 7–8 (n = 20), 9–10 (n = 20), and 11–12 (n = 19) years. The participants completed the MLD test by Auditec®. The Kruskal–Wallis statistical test was used to compare groups. Reference values were obtained by calculating mean, standard deviation, median, mode, and percentiles, while the cutoff criterion was obtained by subtracting two standard deviations from the mean. No statistically significant differences were observed between the groups regarding the MLD test measures. The mean MLD was 10.51 ± 1.84 dB and the cutoff point was set at 7 dB. Thus, reference values for the MLD test were established for children aged 7–12 years, who presented no effect of age on test performance.

This work describes the synthesis and determination of the sun protection factor (SPF) of sunscreen formulations containing two chemical filters obtained from vanillin. The syntheses yield reached 85% and 60% for obtaining the derivative 1 (4-(4hydroxy-3-methoxyphenyl)-3-buten-2-one) and derivative 2 (4-(4-acetyloxy-3methoxyphenyl)-3-buten-2-one), respectively. Formulations containing the chemical filters synthesized, at a concentration of 5.0%(w/w), showed UVB SPF in vitro equal to: derivative 1 (8.5 ± 0.2) and derivative 2 (12.2 ± 0.9). These values were higher than the formulation containing benzophenone-3 (6.9 ± 0.6) at the same concentration.

This work describes the use of tamarindus shell as an alternative adsorbent for the removal of methylene blue and chromium(VI) species from aqueous solutions. The adsorbent at unmodified form was used in sorption studies. The solid was characterized by MEV, BET and BJH. Acidic functional groups on the surface of the adsorbent were seen by FTIR, Boehm's titration and pHPCZ. The results showed that the kinetic equilibrium was reached after 120 and 180 min for the dye and the metal respectively. The kinetic data were better fitted to pseudo-first order for dye adsorption and to pseudo-second order for metal adsorption. The change points in sorption stages (rapid and slow phase) were defined by the MCVP parameter using Hung's algorithm. The effects of pH and ionic strength on adsorption capacity were also studied.