Iridoids from Caryopteris x clandonensis

In continuation of our phytochemical studies on Caryopteris x clandonensis (Lamiaceae), three further iridoids were isolated from the methanolic extra ct of the stems. Their structures were established by 1D and 2D NMR and MS analysis as a C-6 epimer of 8-O-acetylharpagide (6-epi-8-O-acetylharpagide) , a derivative of harpagide which contained the unusual feature of a 3',4' seco-glycopyranosyl moiety (clandonoside II) and a methyl cetal of 8-O-acet ylharpagide aglucone hydrate named clandonensine. (C) 2000 Elsevier Science Ltd. All rights reserved.