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Background:Microbial resistance has become a worldwide public health problem, and may lead to morbidity and mortality in affected patients.Objective:Therefore, this work aimed to evaluate the antibacterial activity of quinone-4-oxoquinoline derivatives.Method:These derivatives were evaluated against Gram-positive and Gram-negative bacteria by their antibacterial activity, anti-biofilm, and hemolytic activities and by in silico assays.Results:The quinone-4-oxoquinoline derivatives presented broad-spectrum antibacterial activities, and in some cases were more active than commercially available reference drugs. These compounds also inhibited bacterial adhesion and the assays revealed seven non-hemolytic derivatives. The derivatives seem to cause damage to the bacterial cell membrane and those containing the carboxyl group at the C-3 position of the 4-quinolonic nucleus were more active than those containing a carboxyethyl group.Conclusion:The isoquinoline-5,8-dione nucleus also favored antimicrobial activity. The study showed that the target of the derivatives must be a non-conventional hydrophobic allosteric binding pocket on the DNA gyrase enzyme.

New porphyrin/4-oxoquinoline conjugates were synthesized from the Heck coupling reaction of a β-brominated porphyrin with 1-allyl-4-oxoquinoline derivatives, followed by demetallation and deprotection affording the promising photosensitizers 9a-e. Singlet oxygen studies have demonstrated that all the porphyrin/4-oxoquinoline conjugates 9a-e were capable of producing cytotoxic species and found to be excellent photosensitizing agents in the inactivation of S. aureus by the antimicrobial photodynamic therapy (aPDT) protocol.

4-quinolones derivatives can present fluorescent properties, depending on their substituents and on the chemical environment (e.g., acidic medium), allowing their application as ion sensors. We theoretically evaluated the photophysical properties of previously synthesized 3-acyl-4-quinolones to verify how different substituents (R1=H, NH2 and R2 = OEt, OH, NHPh) affect their absorption profiles and the emission profile of a reference compound, PB3. All DFT and TD-DFT calculations were performed at B3LYP-D3/6-311++G(d,p) level and continuum polarization model for simulated acetonitrile as solvent. For PB2 (R1 = H, R2 = OEt), we observed hypsochromic shift compared to PB3 due to the increase of the gap between HOMO/LUMO (absence of electron-donating group), in accordance with experimental data. For R1=NH2 and R2=OH, NHPh (PB6 and PB10, respectively), the gap between HOMO/LUMO increases, resulting in a soft bathochromic shift for the simulated absorption spectra. In addition, we evaluated the effect of acid addition on the absorption and emission profile of PB3 and the results were compared with experimental data. Our thermodynamic results suggest that protonation occurs on the endocyclic carbonyl of the quinolone moiety, probably due to an increased aromatic character, as suggested by our NICS calculations. Finally, we associate the increase of the fluorescence in the acidic medium to the establishment of an intramolecular hydrogen bond and, thus, increased rigidity.

INTRODUCTION: Metabolic Race is a board game developed as an educational tool for health students. Based on diagnostic scores for Metabolic Syndrome, Diabetes Mellitus, dyslipidemia, obesity and in the prevention of these diseases, this game allows students to learn in a didactic way the clinical relevance of biochemical phenomena. OBJECTIVES: The game aims to consolidate Metabolic Syndrome biochemical events, diagnostic criteria and risk factors. MATERIALS AND METHODS: The board simulates the environment and routine experienced by university students that could contribute to the development of Metabolic Syndrome. Each group receives a board, pins, dice, question, challenge and diagnostics cards. Players move along a simplified map of Niterói city, where places as Antônio Pedro Hospital (HUAP) are pointed out. The scoring system is based on 3 criteria for Metabolic Syndrome diagnosis: glycemia, abdominal obesity and HDL cholesterol. Students can play as patients or doctors and as they move along the board their glicemia, waist circumference and HDL cholesterol change according to their diet and how much exercise they practice. At the end, it is possible to calculate each player’s rate and provide proportional diagnosis. The healthiest patient that arrives at HUAP wins. DISCUSSION AND RESULTS: Over the last 2 years, the game has been played by 81 medical students currently attending to biochemical classes. They classified the activity as an important educational support, since 91% agreed it complements and consolidate topics discussed in classroom. It was considered entertaining by 74% of them and 86% pointed they would play again. The subject-matter was classified as difficult by 10%, highlighting the need of new methods to enhance teaching and learning process. Finally, 98% believe that games are able to optimize learning. CONCLUSION: Students who played the game were able to understand Metabolic Syndrome as a set of metabolic disorders, to identify its diagnostic criteria and risk factors.