Several health benefits have been attributed to members of the Verbesina genus, including promotion of urinary and gastrointestinal health. Verbesina species are also reported to exhibit antibacterial, antiparasitic, and antioxidant activities. Although members of the Verbesina genus produce various pharmacologically relevant chemicals as secondary metabolites, including eudesmanes, flavonoids, guanidine alkaloids, acetylenic compounds, and germacrenes, the active compounds required for these benefits remain unknown. To investigate potential antimicrobial activities of Verbesina negrensis, crude extracts from plant aerial structures were evaluated. Following chemical fractionation, the chloroformic extract from Verbesina negrensis was subjected to bioassay-guided isolation using disk diffusion assays to determine antimicrobial activity. The active compound was characterized as 6 beta-cinnamoyloxy-1 beta-hydroxy-10 alpha-metoxy-3-oxo-germacra-4,5Z-ene (1). Fractions containing 1 inhibited both Enterococcus faecalis (ATCC 29212) and Staphylococcus aureus (ATCC 29213). The MIC for 1 was determined by microbroth dilution assay to be 64 mu g/mL for both E. faecalis and S. aureus.
New Antibacterial Germacrene from Verbesina negrensis
DE TOMMASI, Nunziatina;
2013-01-01
Abstract
Several health benefits have been attributed to members of the Verbesina genus, including promotion of urinary and gastrointestinal health. Verbesina species are also reported to exhibit antibacterial, antiparasitic, and antioxidant activities. Although members of the Verbesina genus produce various pharmacologically relevant chemicals as secondary metabolites, including eudesmanes, flavonoids, guanidine alkaloids, acetylenic compounds, and germacrenes, the active compounds required for these benefits remain unknown. To investigate potential antimicrobial activities of Verbesina negrensis, crude extracts from plant aerial structures were evaluated. Following chemical fractionation, the chloroformic extract from Verbesina negrensis was subjected to bioassay-guided isolation using disk diffusion assays to determine antimicrobial activity. The active compound was characterized as 6 beta-cinnamoyloxy-1 beta-hydroxy-10 alpha-metoxy-3-oxo-germacra-4,5Z-ene (1). Fractions containing 1 inhibited both Enterococcus faecalis (ATCC 29212) and Staphylococcus aureus (ATCC 29213). The MIC for 1 was determined by microbroth dilution assay to be 64 mu g/mL for both E. faecalis and S. aureus.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
