Champanones, yellow pigments from the seeds of champa ( Campomanesia lineatifolia)

Two new yellow pigments, named champanones A ( 1) and B ( 2), were isolated from the methanol extract of the seeds of Campomanesia lineatifolia (Myrtaceae). Their structures were established on the basis of NMR and MS studies. Chemical investigation of the methanol extract of the seeds of Campomanesia lineatifolia Ruiz and Pav. (Myrtaceae) led to the isolation of two new β-triketone type compounds, named champanones A ( 1) and B ( 2), together with the known 2,3-dihydro-5-hydroxy-6,8,8-trimethyl-2-phenyl-4H-1-benzopyran-4,7(8H)-dione (champanone C) ( 3). The structures of 1 and 2 were determined to be 2,2,4,4-tetramethyl-6-(1-oxo-3-phenylprop-2-enyl) cyclohexane-1,3,5-trione (occurs as an enol form) and 2,2,4-trimethyl-6-(1-oxo-3-phenylprop-2-enyl)cyclohexane-1,3,5-trione (occurs as an enol form), respectively, by means of spectroscopic analysis. The three compounds showed mild antimicrobial activity.