Identification of a sucrose diester of a substituted beta-truxinic acid in oats.

A novel compound, 4,4'-dihydroxy-3,3'-dimethoxy-beta-truxinic acid esterified to sucrose through the fructosyl 3-and 6-carbons (1), was isolated from oat grains (Avena sativa L.). Its structure was determined by a combination of mass spectrometry and 1-D and 2-D NMR. The amounts of 1 in groats of six different oat cultivars ranged from 101 to 150 microg g(-1) (dry wt). None was detected in the hulls. The free diacid, 4,4'-dihydroxy-3,3'-dimethoxy-beta-truxinic acid (2), could not be detected in groats nor in hulls.