Annurcoic acid: A new antioxidant ursane triterpene from fruits of cv. Annurca apple

‘Annurca’ is a variety of apple produced in the south of Italy. The phytochemical study of the ethereal extract of the reddened fruits led to the isolation of a new ursane triterpen, as well as five known compounds, which were identified by spectroscopic techniques. The new compound was identified as the acid, 1α,19α-dihydroxyursan-28-oic, and named annurcoic acid. Antioxidant activities of all the isolated compounds were assessed by measuring their ability to scavenge 2,2′-diphenyl-1-picrylhydrazyl (DPPH) radicals and to inhibit the autoxidation of methyl linoleate (MeLo) in vitro.