A new lignan glycoside, aviculin [1], was isolated from the whole plant of Polygonum avtculare along with the known compounds juglanin [2], avicularin [3], astragalin [4], and betmidin [5]. The structure of the new compound was elucidated on the basis of spectroscopic and chemical evidence.Polygonum avtculare L. (Polygonaceae) is a medicinal plant frequently employed in Korean traditional medicine. The whole plant has been used as an antipyretic, antiparasitic, and diuretic agent (1,2). This paper deals with the structural elucidation of a new lignan glycoside, aviculin [1], and the isolation from this plant of four flavonoid glycosides (3-5), juglanin [2], avicularin [3], astragalin [4], and betmidin [5].
RESULTS AND DISCUSSIONThe EtOAc-soluble fraction of the aqueous MeOH extract afforded 1, C26H34O10, amorphous powder, mp 155-157°, [a]25D +20.27°( ¿=0.074, MeOH). On acetylation with Ac20 and pyridine, compound 1 afforded a hexaacetate [la], as an oily compound (6).Acidic hydrolysis of compound 1 yielded L-rhamnose and an aglycone having identical specific rotation and eims data with those of (+)-isolariciresinol [lb] (7). The cd of the aglycone was a mirror image to that of ( -)-isolariciresinol (8), with known absolute configuration (9), and also in agreement with published cd data of (+)isolariciresinol dimethyl ether (10). The eims spectrum of compound 1 showed a molecular ion peak at miz 506, besides significant fragment peaks at mlz 359 [M-rhamnose]+, 341 [M-rhamnose-H20]+, 311 [M-rhamnose-H20-OCHJ+,
