RESUMO
Fungal infections currently remain as a common problem in public health. Actually, drug discovery programs are oriented to the searching for lead structures. Virtual screening and molecular docking constitute great alternatives in order to find hit compounds. Novel infection targets can also be defined and employed together with molecular docking tools in drug discovery programs. Thus, thirty-two natural compounds were docked within the active site of N-myristoyl transferase (NMT) as antifungal enzyme target. From tested compounds, alkaloids, flavonoids, xanthones, and quinones exhibited strongest mean interaction with NMT than terpenoids, coumarins and phenolics. Particularly, affinities for one aporphine alkaloid, a prenylated flavonoid and two xanthones resulted to be comparable with that of previously reported synthetic inhibitor. Several hydrophobic and polar contacts were demonstrated by comparing different computational tools. The present results let to establish three possible lead structures to develop antifungal drugs although subsequent SAR analyses are still required.
Las infecciones causadas por hongos continúan siendo un problema de salud pública en la actualidad. De hecho, existen diversos programas para el descubrimiento de fármacos enfocados en la búsqueda de estructuras plantilla. El mapeo virtual junto con docking molecular constituye una alternativa importante para encontrar potenciales estructuras promisorias. Mediante herramientas de docking molecular se pueden definir nuevos blancos terapéuticos para combatir diversas infecciones. Por tanto, se llevó a cabo el estudio del acoplamiento molecular a treinta y dos compuestos de origen natural, empleando la N-miristoil transferasa (NMT) como blanco enzimático antifúngico. De los compuestos ensayados, alcaloides, flavonoides, xantonas y quinonas mostraron interacción media más fuerte con la NMT que los terpenos, cumarinas y fenólicos. Particularmente, la afinidad encontrada para un alcaloide aporfínico, un flavonoide prenilado y dos xantonas resultó comparable con la encontrada para un inhibidor sintético reportado. En el presente trabajo se demostraron varias interacciones tanto hidrofóbicas como hidrofílicas mediante diversas herramientas computacionales. Los resultados encontrados permiten establecer tres posibles estructuras promisorias para el desarrollo de fármacos antifúngicos, aunque se requiere aún de estudios de relación estructura-actividad.
RESUMO
The in vitro anti-inflammatory effects of seven known lignans and one dihydrochalcone isolated from the leaves of two Lauraceae species (Pleurothyrium cinereum and Ocotea macrophylla), were evaluated through the inhibition of COX-1, COX-2, 5-LOX and the aggregation of rabbit platelets induced by PAF, AA and ADP. (+)-de-4"-O--methylmagnolin 4 was found to be a potent COX-2/5-LOX dual inhibitor and PAF-antagonist (COX-2 IC50 2.27 µM; 5-LOX IC50 5.05 µM; PAF IC50 2.51 µM). However, all compounds exhibited an activity at different levels, indicating good anti-inflammatory properties to be considered in further structural optimization studies.
Os efeitos anti-inflamatórios in vitro de sete conhecidos lignanos e uma dihidrocalcona isolados das folhas de duas espécies da família Lauraceae (Pleurothyrium cinereum e Ocotea macrophylla) foram avaliados por meio da inibição da COX1, COX-2, 5-LOX e agregação de plaquetas de coelhos induzida por PAF, AA e ADP. A (+)-4"-O-metilmagnolina-4 foi encontrada como mais potente inibidora tanto da COX-2 quanto de 5-LOX e antagonista de PAF (COX-2 IC50 2,27 µM; 5- LOX IC50 5,05 µM; PAF IC50 2,51 µM). Entretanto, todos compostos mostram uma atividade em intensidades diferentes, indicando boas propriedades anti-inflamátorias a serem consideradas para futuros estudos de modificações e otimização estruturais.