The use of isoxazoline and isoxazole scaffolding in the design of novel thiourea and amide liquid-crystalline compounds

The authors wish to thank the Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior - Brasil (CAPES) - Finance Code 001 for the fellowships and Conselho Nacional de Pesquisa Cientifica (CNPq, edital Universal) for the financial support grant n. 403075 2016-5.A series of novel thiourea and amide liquid crystals containing 5-membered isoxazoline and isoxazole rings were synthetized and the liquid crystal properties studied. Thioureas were obtained using a condensation reaction of benzoyl chlorides, arylamines and ammonium thiocyanate. The amides, on the other hand, were the byproduct of a quantitative reaction which used potassium cyanate as the starting material. Thiourea and amide derivatives were predominantly SmA mesophase inductors. A nematic mesophase was observed only for thioureas and amides containing an isoxazole ring. Additionaly, the liquid crystal behavior was also dependent on the relative position of nitrogen and oxygen atoms on the 5-membered heterocycle.publishersversionpublishe

Inhibition of Tyrosinase by 4H-Chromene Analogues: Synthesis, Kinetic Studies and Computational Analysis

Inhibition of mushroom tyrosinase was observed with synthetic dihydropyrano[3,2-b]chromenediones. Among them, DHPC04 displayed the most potent tyrosinase inhibitory activity with a Ki value of 4μM, comparable to the reference standard inhibitor kojic acid. A kinetic study suggested that these synthetic heterocyclic compounds behave as competitive inhibitors for the L-DOPA binding site of the enzyme. Furthermore, molecular modeling provided important insight into the mechanism of binding interactions with the tyrosinase copper active site

Síntese da fenitoína assistida por micro-ondas: proposta de aula prática para alunos de graduação

Microwave synthesis is considered a breakthrough in the field of chemistry due to its benefits over conventional heating methods. We describe, for the first time, the total synthesis of phenytoin adapted for a microwave reactor, proposed as an experiment for undergraduate courses. When carried out with microwaves, the synthetic route provided phenytoin in 6 min and 30 s, while for conventional heating the total time was 170 min. The experiment also involves rapid identification of compounds by TLC, ¹H NMR, FT-IR and melting points determination

Synthesis of novel kavain-like derivatives and evaluation of their cytotoxic activity

Palladium-catalyzed cross coupling reactions (Sonogashira-Hagihara, Suzuki-Miyaura, and Heck) coupling and nickel hydride-mediated tandem isomerization aldolisation have been used for the synthesis of three series of δ-valerolactones substituted in positions 3, 4, 5 and 6 of the lactone ring. The 26 kavaïn-like derivatives were tested against three cell lines and five of them exhibited a weak cytotoxic activity

Synthesis of Limonene β-Amino Alcohol Derivatives in Support of New Antileishmanial Therapies

A series of seven limonene β-amino alcohol derivatives has been regioselectively synthesised in moderate to good yields. Two of these compounds were found to be significantly effective against in vitro cultures of the Leishmania (Viannia) braziliensis promastigote form in the micromolar range. The activities found for 3b and 3f were about 100-fold more potent than the standard drug, Pentamidine, in the same test, while limonene did not display any activity. This is the first report of antileishmanial activity by limonene β-amino alcohol derivatives

Syntheis and in vivo assay of indometacin esters as a Medicinal Chemistry practical class for graduate students

This article shows a Medicinal Chemistry practical class, created and developed by students of the Pharmaceutical Sciences Post-Graduate Program (PPGCF/UFRGS). It describes the planning, synthesis and in vivo biological evaluation of four ester derivatives of the non-steroidal anti-inflammatory drug Indomethacin (IndOH) as a proposal for practical classes of Medicinal Chemistry.Este artigo apresenta uma aula prática de Química Medicinal, criada e desenvolvida por estudantes do Programa de Pós-Graduação em Ciências Farmacêuticas (PPGCF/UFRGS). Descreve o planejamento, síntese e avaliação biológica de quatro ésteres derivados do fármaco anti-inflamatório não-esteróide Indometacina (IndOH) como aula prática para alunos de Química Medicinal.Colegio de Farmacéuticos de la Provincia de Buenos Aire