[Lignans from flower buds of Magnolia biondii].

The present study aims to investigate the lignans from the flower buds of Magnolia biondii. The isolation and purification of the compounds were performed by column chromatographies on Diaion HP-20, silica gel, and Sephadex LH-20, combined with semi-preparative HPLC. Their structures were elucidated on the basis of spectral data and physiochemical properties. Eighteen compounds were isolated and identified as magnolin (1), epimagnolin (2), eudesmin (3), kobusin (4), aschantin (5), lirioresinol B dimethyl ether (6), pinoresinol monomethy ether (7), (+)-de-O-methylmagnolin (8), isoeucommin A (9), syringaresinol 4-O-ß-D-glucopyranoside (10), phillygenin (11), lariciresinol-4'-O-ß-1-D-glucoside (12), conicaoside (13), (7'S, 8'R)-dihydrodehydrodiconiferylalcohol (14), 7R*, 8S*-dihydrodehydrodiconiferyl alcohol 4-O-ß-D-glucopyranoside (15), 7S, 8R-erythro-7, 9, 9'-trihydroxy-3, 3'-dimethoxy-8-O-4'-neolignan 4-O-ß-D-glucopyranoside (16), 7S, 8R-erythro-4, 9, 9'-trihydroxy-3, 3'-dimethoxy-8-O-4'-neolignan-7-O-ß-D-glucopyranoside (17), and (+)-isolariciresinol (18). Compounds 7-18 are isolated from this plant for the first time.

Four New Monoterpenoid Glycosides from the Flower Buds of Magnolia biondii.

Four new monoterpenoid glycosides 1-4, named magnoliaterpenoid A-D, were isolated from a 50% aqueous acetone extract of flower buds of Magnolia biondii, along with one known compound, (1'R,3'S,5'R,8'S,2Z,4E)-dihydrophaseic acid 3-O-ß-d-glucopyranoside (5). Their structures and relative configuration were identified by extensive spectroscopic analysis (IR, UV, MS, 1D and 2D NMR). The aglycones of these four new compounds possess seven-membered rings systems, which are very rare. A plausible biosynthetic route for the four new compounds was proposed via the biogenetic isoprene rule. Compounds 1, 2, 3, and 4 showed no antimicrobial activity at the concentration range of 1.95-250 µg/mL.