Abstract
A major polyphenol from P. japonicus, named fukinolic acid (XII), was isolated and its structure was investigated. Fukinolic acid afforded a new polyphenol named fukiic acid (I) and caffeic acid on hydrolysis in molar ratio 1:1. The structure of fukiic acid was established as 2, 3-dihydroxy-4-(3', 4'-dihydroxyphenyl)-3-carboxybutyric acid (I), and its methyl derivatives were described.
Based on evidences presented, the structure for fukinolic acid was proposed as XII. It was further demonstrated that fukinolic acid caused the brown discoloration on action of a polyphenoloxidase from the plant tissues.
