RESUMEN Introducción: La miel es una sustancia natural producida por las abejas, principalmente, a partir del néctar de flores con alto valor nutricional. Sin embargo, muchas muestras comercializadas están adulteradas o falsificadas. Método: Compramos doce mieles en mercados de la ciudad de Betim (Brasil) y analizamos su acidez, pH, conductividad eléctrica, materia insoluble, cenizas, contenido de humedad, presencia de bacterias mesófilas, mohos, levaduras, coliformes totales, Salmonella spp. y la presencia de granos de polen. Resultados: Considerando todas las muestras de miel, el pH promedio fue de 3,8 ± 0,5 y la acidez libre promedio fue de 29,8 ± 6,6 mEq/kg. Considerando la acidez, encontramos el promedio de acidez lactónica 6,4 ± 2,4 mEq/kg y una acidez promedio total de 36,2 ± 6,9 mEq/kg. El contenido de humedad promedio fue 19,4 ± 1,0 %, la conductividad eléctrica promedio fue 391,6 ± 168,6 μS/crn, la cantidad promedio de cenizas fue 0,5 ± 0,8 % y la materia insoluble promedio fue 0,08 ± 0,02 %. Sólo la humedad fue significativamente diferente entre los dos grupos y diez de las muestras de miel tenían granos de polen. Conclusiones: Los parámetros de calidad de las muestras etiquetadas y no etiquetadas no fueron significativamente diferentes, aunque dos muestras de miel no etiquetadas fueron fraudulentas, debido a la ausencia de granos de polen. Identificar la presencia o ausencia de polen en las muestras es un primer paso seguro, económico y confiable para verificar la autenticidad de la miel.

SUMMARY Introduction: Honey is a natural substance produced by bees mainly from flower nectar with high nutritional value. However, many commercialized samples are adulterated or falsified. Method: We bought twelve honey samples in markets in the city of Betim (Brazil) and analyzed their acidity, pH, electrical conductivity, insoluble matter, ashes, moisture content, presence of mesophile bacteria, molds, yeasts, total coliforms, Salmonella spp. and the presence of pollen grains. Results: Considering all honey samples, the average pH was 3.8 ± 0.5 and the average free acidity was 29.8 ± 6.6 mEq/kg. Considering acidity, we found the average of lactonic acidity 6.4 ± 2.4 mEq/kg and a total average acidity of 36.2 ± 6.9 mEq/kg. The average moisture content was 19.4 ± 1.0 %, the average electrical conductivity was 391.6 ± 168.6 μS/ cm, the average amount of ashes was 0.5 ± 0.8 % and the average insoluble matter was 0.08 ± 0.02 %. Only the moisture was significantly different between the two groups and ten honey samples had pollen grains. Conclusions: The quality parameters of the labeled and unlabeled samples were not significantly different, although two samples of unlabeled honey were fraudulent, mainly due to the absence of pollen grains. Identifying the presence or absence of pollen in the samples is a safe, economical, and reliable first step for verifying the authenticity of the honey.

RESUMO Introdução: O mel é uma substância natural produzida pelas abelhas principalmente a partir do néctar da flor com alto valor nutritivo. No entanto, muitas amostras comercializadas são adulteradas ou falsificadas. Método: Compramos doze méis em mercados da cidade de Betim (Brasil) e analisamos sua acidez, pH, condutividade elétrica, sólidos insolúveis, cinzas, teor de umidade, presença de bactérias mesófilas, bolores, leveduras, coliformes totais, Salmonella spp. e a presença de grãos de pólen. Resultados: Considerando todas as amostras de mel, o pH médio foi de 3,8 ± 0,5 e a acidez livre média foi de 29,8 ± 6,6 mEq/kg. Considerando a acidez, encontramos a média de acidez lactô-nica de 6,4 ± 2,4 mEq/kg e uma acidez média total de 36,2 ± 6,9 mEq/kg. O teor de umidade médio foi de 19,4 ± 1,0 %, a condutividade elétrica média foi 391,6 ± 168,6 μS/cm, a quantidade média de cinzas foi 0,5 ± 0,8 % e a matéria insolúvel média foi 0,08 ± 0,02 %. Apenas a umidade foi significativamente diferente entre os dois grupos e dez das amostras de mel apresentaram grãos de pólen. Conclusões: Os parâmetros de qualidade das amostras rotuladas e não rotuladas não foram diferentes, embora duas amostras de mel não rotulado fossem fraudulentas, principalmente devido à ausência de grãos de pólen. Identificar a presença ou ausência de pólen nas amostras é um primeiro passo seguro, económico e confiável para verificar a autenticidade do mel.

Abstract Candida spp. is considered an important cause of healthcare-associated infections worldwide. Currently, the emergence and spread of resistant Candida isolates are being increasingly reported, making the development of new agents urgently needed. In this study, we showed the in vitro anti-Candida activity of seven synthetic 3-alkylpyridine alkaloid analogs. Among them, alkaloid 1 presented a potent antifungal effect, which was independent of its capacity of binding with the fungal membrane ergosterol or cell wall. Analog 1 showed fungistatic and fungicidal effects against C. albicans (MIC 7.8 μg/mL and MFC 62.5 μg/mL), C. glabrata, C. krusei (MIC and MFC 31.2 μg/mL), and C. tropicalis (MIC 31.2 μg/mL and MFC 125 μg/mL). The time kill-curve study showed that compound 1 has a potent fungicidal effect in vitro, eliminating C. albicans cells. Furthermore, an in vitro synergistic effect with ketoconazole was observed for compound 1. This compound also eliminated the yeast-to-hypha transition. However, it showed high cytotoxicity against mammalian cells. Taken together, these findings support the use of compound 1 as a prototype to develop new anti-Candida agents, but molecular modifications should be done to minimize the high cytotoxicity obtained.

The emergence of antibiotic resistance among microbial pathogens is a serious public health problem, resulting in a constant need of discovering new antibiotics. For this purpose, we synthetized and determined the antimicrobial activity of copper (Cu), cobalt (Co), and tin (Sn) complexes coordinated with scorpionate ligand in a tridentate mode against microorganisms of clinical importance. New complexes with the sodium hydrotris(2-mercaptothiazolyl)borate ligand were characterized by physicochemical and spectroscopic techniques (UV-vis, IR, 1H and 13C NMR). Moreover, their antimicrobial activity was evaluated using microdilution broth method. Cytotoxicity was determined in Vero cells and the selectivity index (SI) was calculated. The coordination with metals increased the ligand antimicrobial activity, which showed no activity when evaluated alone (MIC>1,080 µM). Cu-complex (1) had activity against Candida albicans and C. krusei, with MICs of 130 and 66 µM, respectively. The compounds had low toxicity on Vero cells and chemo-informatics assays corroborated a low systemic toxic effect. The SI revealed that the compound 1 was 16 times more selective for C. krusei and 8 times more selective for C. albicans in relation to Vero cells. The Cu-complex stands out as a potential prototype for the development of new antifungal agents.