A new coumarin derivative, 4-acetatecoumarin, with antifungal activity and association study against Aspergillus spp

Abstract Fungal infections have become a concern for health professionals, and the emergence of resistant strains has been reported for all known classes of antifungal drugs. Among the fungi causing disease, we highlight those that belong to the genus Aspergillus. For these reasons, the search for new antifungals is important. This study examines the effects of a coumarin derivative, 4-acetatecoumarin (Cou-UMB16) both alone and together with antifungal drugs, and its mode of action against Aspergillus spp. Cou-UMB16 was tested to evaluate its effects on mycelia growth, and germination of Aspergillus spp. fungal conidia. We investigated its possible action on cell walls, on the cell membrane, and also the capacity of this coumarin derivative to enhance the activity of antifungal drugs. Our results suggest that Cou-UMB16 inhibits Aspergillus spp. virulence factors (mycelia growth and germination of conidia) and affects the structure of the fungal cell wall. When applying Cou-UMB16 in combination with azoles, both synergistic and additive effects were observed. This study concludes that Cou-UMB16 inhibits mycelial growth and spore germination, and that the activity is due to its action on the fungal cell wall, and that Cou-UMB16 could act as an antifungal modifier.

Morphological alterations and time-kill studies of the essential oil from the leaves of Coriandrum sativum L. on Candida albicans / Alteraciones morfológicas y estudios de letalidad del aceite esencial de las hojas de Coriandrum sativum L. en Candida albicans

The objective of this study was to evaluate the morphological alterations and time-kill of the essential oil of the leaves of C. sativum L. on strains of C. albicans. The essential oil was submitted to gas chromatography-mass spectrometry analysis. The predominant component identified was linalool (39.78 percent). Minimal inhibitory concentration and minimal fungicidal concentration of the essential oil were respectively 512 and 1024 ug.mL-1 for 90 percent of the strains tested. In the time-kill curves, the essential oil showed a concentration-dependent fungicidal effect. In the micromorphology assay it caused a significant reduction in pseudohyphae, an important pathogenic factor of C. albicans.

El objetivo de este estudio fue evaluar las alteraciones morfológicas y de letalidad del aceite esencial de las hojas de C. sativum L. en cepas de C. albicans. El aceite esencial se presentó a gas análisis de espectrometría de cromatografía-masa. El componente predominante identificado fue linalol (39,78 por ciento). Concentración inhibitoria mínima y concentración mínima fungicida del aceite esencial fueron, respectivamente, 512 y 1.024 ìg.mL-1 para 90 por ciento de las cepas probadas. En las curvas el tiempo-matar, el aceite esencial mostró un efecto fungicida dependiente de la concentración. En el ensayo de micromorfología causó una reducción significativa en pseudohifas, un importante factor patógeno de C. albicans.

Antibacterial activity of flavonoid 5.7.4’-trimethoxyflavone isolated from Praxelis clematides R.M. King & Robinson / Actividad antibacterial del flavonoide 5.7.4’-trimetoxiflavona aislada dePrexelis clematides R.M. King & Robinson

The flavonoids are a large class of polyphenolic compounds found in plants that are known to exhibit biological effects. In the study, the flavonoid 5.7.4’-trimethoxyflavone (TMF) extracted from Praxelis clematidea was evaluated for its antibacterial activity. Microdilution method was used for antibacterial assay of the flavonoid and eleven bacteria strains were used in the study for activities. The results were also compared with the standard drug, Chloramphenicol (100 ug/mL). The results obtained showed activity of the flavonoid against Gram positive and Gram negative bacteria.

Los flavonoides son una clase importante de compuestos polifenólicos encontrados en las plantas que se sabe que presentan efectos biológicos. En el estudio, el flavonoide 5.7.4 '-trimethoxyflavone (TMF) extraído de Praxelis clematidea fue evaluado por su actividad antibacteriana. Se utilizó el método de microdilución para el ensayo antibacteriano del flavonoide y once cepas de bacterias se usaron en el estudio de las actividades. Los resultados se compararon también con el fármaco estándar, Cloranfenicol (100 ug/mL). Los resultados obtenidos mostraron actividad del flavonoide contra bacterias Gram positivas y Gram negativas.