The content of lignan glycosides in Forsythia flowers and leaves.

Quantitative determination of lignan glucosides in flowers and leaves of three taxons of Forsythia Vahl was performed using the HPLC method. The main lignan compound in the flowers of F. suspensa appeared to be (+)-pinoresinol beta-D-glucopyranoside, whereas in the leaves of this species phillyrin was the predominant lignan. The content of (+)-pinoresinol beta-D-glucopyranoside in F. suspensa flowers amounted to 4.3-7% and that of phillyrin did not reach 1%. The inverse ratio of (+)-pinoresinol beta-D-glucopyranoside to phillyrin occurred in the leaves of F. suspensa, which contained up to 4.3% of phillyrin and 1.6% and less (+)-pinoresinol beta-D-glucopyranoside. The flowers of F. viridissima and F. x intermedia were rich in arctiin: 5.5-10.2% and up to 11.5%, respectively. The leaves of these two species contained less arctiin: up to 4.3% in F. viridissima and up to 2.3% in F. x intermedia. The flowers showed the highest level of lignans at the phase of buds, it decreased during the blooming time.