A new C-methyl-flavone and other compounds from Myrcia guianensis

This study reports the isolation of one new C-methyl-flavone (6,8-dimethyl-4′,5-dihydroxy-3′,7-dimethoxyflavone, 1), along with one C-methyl-flavone (sideroxylin, 2), one known C-methyl-flavonol (quercetin, 3), two C-methyl-flavonol glycosides [(quercitrin, 4) and (guaijaverin, 5)], one lignan (9′,9′-O-feruloyl-(−)-seco-isolaricinresinol, 6) and gallic acid (7) from Myrcia guianensis (Aubl.) DC. The structural elucidation of compounds 1–7 was performed based on the detailed analysis of their NMR spectra and the comparison with the literature. This is the first report of compound 2 in the genus Myrcia and of compounds 3, 4, and 5 in M. guianensis, whereas compound 6 has not been isolated from any species of the Myrtaceae family. C-methyl-flavonoids are frequently isolated from Myrtaceae species; thus, the occurrence of C-methyl-flavones and C-methyl-flavonols in M. guianensis may present chemophenetics relevance to the consolidation of the genus Myrcia within the Myrtaceae family.