Identification of a sucrose diester of a substituted β-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 mug 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. (C) 2001 Elsevier Science Ltd. All rights reserved.