Flavonoids from lemon balm (Melissa officinalis L., Lamiaceae).

Six flavonoids have been isolated from the leaves of lemon balm (Melissa officinalis L., Lamiaceae). Their structures were determined on the basis of spectral data (UV, 1R, 1H NMR, 13C NMR and FAB MS) as luteolin, luteolin 7-O-beta-D-glucopyranoside, apigenin 7-O-beta-D-glucopyranoside, luteolin 7-O-beta-D-glucuronopyranoside, luteolin 3'-O-beta-D-glucuronopyranoside and luteolin 7-O-beta-D-glucopyranoside-3'-Obeta-D-glucuronopyranoside. The last three glycosides have been found in lemon balm for the first time and luteolin 7-O-beta-D-glucopyranoside-3'-O-beta-D-glucuronopyranoside is a new compound found in plants.