Agastinol and Agastenol, Novel Lignans from Agastache rugosa and Their Evaluation in an Apoptosis Inhibition Assay

Investigation of the whole plant of Agastache rugosa resulted in the isolation of two new lignan compounds. Their structures were elucidated as (8S,7'R,8'S)-4-hydroxybenzoic acid 4-(4-hydroxy-3-methoxybenzyl)-2-(4-hydroxy-3-methoxyphenyl)tetrahydrofuran-3-ylmethyl ester (agastinol, 1) and (7'R,8'S)-4-hydroxybenzoic acid 4-(hydroxy-3-methoxybenzylidene)-2-(4-hydroxy-3-methoxyphenyl)-tetrahydrofuran-3-ylmethyl ester (agastenol, 2). Agastinol and agastenol inhibited etoposide-induced apoptosis in U937 cells with IC50 values of 15.2 and 11.4 microg/mL, respectively.