Antifungal Activity of Alpha-Mangostin against In Vitro and In Vivo.

We investigated alpha-mangostin (α-mangostin, α-MG), a xanthone natural product extracted from the pericarp of mangosteen (), for its antifungal activities and possible mechanism against which causes mango anthracnose. The results demonstrated that α-MG had a relatively high in vitro inhibitory activity against among 20 plant pathogenic fungi. The median effective concentration (EC) values of α-MG against mycelial growth were nearly 10 times higher than those of spore germination inhibition for both strains of , the carbendazim-sensitive () and carbendazim-resistant (). The results suggested that α-MG exhibited a better inhibitory effect on spore germination than on the mycelial growth of . Further investigation indicated that the protective effect could be superior to the therapeutic effect for mango leaves for scab development. The morphological observations of mycelium showed that α-MG caused the accumulation of dense bodies. Ultrastructural observation further revealed that α-MG caused a decrease in the quantity and shape of the swelling of mitochondria in the mycelium cells of . In addition, bioassays disclosed that the inhibitory activity of α-MG on spore germination was reduced by adding exogenous adenosine triphosphate (ATP). These results suggested that the mode of action of α-MG could be involved in the destruction of mitochondrial energy metabolism. The current study supports α-MG as a natural antifungal agent in crop protection.