Abstract From the leaves of Bupleurum salicifolium two benzylidene-benzyl-γ-butyrolactone- type lignans were isolated. One was identified as kaerophyllin, the other as its cis-isomer, hitherto unreported. The latter was characterized as 2 (3, 4-dimethoxy)-benzylidene-3-(3, 4- dioxymethyl)-phenylmethyl-3 S-γ-butyrolactone by spectroscopic chemical methods, and from a study of its derivatives.
