Caffeoyl Triterpenes from Pear (Pyrus pyrifolia Nakai) Fruit Peels and Their Antioxidative Activities against Oxidation of Rat Blood Plasma

Six triterpenes, including three caffeoyl triterpenes, were purified and isolated from pear fruit (Pyrus pyrifolia Nakai cv. Chuwhangbae) peel extracts using various column chromatography techniques with a guided 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging assay. The isolated compounds were identified as betulinic aldehyde (1), lupeol (2), betulinic acid (3), 3-O-cis-caffeoylbetulinic acid (4), 3-O-trans-caffeoylbetulinic acid (5),...