Iridoid keto-glycosides from Caryopteris x Clandonensis

Two new iridoid keto-glycosides, clandonoside and 8-O-acetylclandonoside, t ogether with their hydrates, were isolated from the stems of Caryoptetis x Clandonensis besides the known harpagide and 8-O-acetylharpagide. The struc ture of clandonoside and 8-O-acetylclandonoside were established as harpagi de-aglucone-1-O-beta-D-ribohexo-3-ulopyranoside and 8-O-acetylharpagide-agl ucone-1-O-beta-D-ribohexo-3-ulopyranoside, respectively, by spectroscopic m ethods. This is the first report of a C-1 linked beta-Dribohexo-3-ulopyrano se (beta-D-ketohexose) iridoid. (C) 1999 Elsevier Science Ltd. All rights r eserved.