Studies on the constituents of aceraceae plants. II. Structure of aceroside I, a glucoside of a novel cyclic diarylheptanoid from Acer nikoense Maxim.

The structure of aceroside I, C25H32O8, mp 170-171°(acetone), [α]20D-7.7°, which was isolated from the stem bark of Acer nikoense MAXIM. (Aceraceae), was established to be acerogenin A β-D-glucopyranoside represented by formula 1. Acerogenin A, C19H22O3, mp 151-152°, [α]20D+57.3°, was concluded to be a m-, p'-bridged diphenyl ether type diarylheptanoid (2) on the basis of chemical and spectroscopic (especially NMR) evidences. The stereostructure of 2 was determined by derivation of acerogenin A (2) into (S)-1-(p-hydroxyphenyl)-7-(p-methoxyphenyl)-heptan-3-ol. Acerogenin A (2) is the first example of a novel type of diarylheptanoid-20-oxa-[7, 1]-metapara-cyclophane.