Jacaranone Derivatives from Senecio laetus (Compositae)

Seven jacaranone derivatives were isolated from the MeOH extract of the whole plants of Senecio laetus. Structures of the compounds were elucidated on the basis of extensive spectroscopic. They were jacaranone ( 1) ; 3-hydroxy-2,3-dihydrojacaranone methyl ester ( 2) ; 1-hydroxy-4-oxo-2,5-hex edine-1-ethyl acetate ( 3) ; the mixture of 2-jacaranoneacyl-α-D-pyran glucose ester and 2-jacaranoneacyl-β-D-pyran glucose ester ( 4,5) ; l-jacara-nonacetate-β-D-pyran glucose ester ( 6) and 1-hydroxy-4-oxo-2,5-hexedine-1-ethylic acid ( 7 ) . The jacaranone derivatives were all isolated from this plant for the first time. The results supported that jacaranone derivatives could be characteristic secondary metabolite of Senecio.