Abstract
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The four new diterpene and diterpene glucosides 1–4, the new bergamotene derivative 5, and the two new iridoid monoterpenoid glucosides 6 and 7, together with the eleven known compounds 8–18, were isolated from the EtOH extract of the roots of Phlogacanthus curviflorus. On the basis of chemical and spectroscopic evidence, their structures were identified as (4__α__,5__β__,10__α__,14__α__)‐14,19‐dihydroxyabieta‐8,13(15)‐dieno‐16,12‐lactone 19‐(β‐D‐glucopyranoside) (=curvifloruside A; 1), (4__α__,5__β__,10__α__,14__α__)‐14,19‐dihydroxyabieta‐8,13(15)‐dieno‐16,12‐lactone 19‐[2‐O‐(4‐hydroxy‐3,5‐dimethoxybenzoyl)‐β‐D‐glucopyranoside] (=curvifloruside B; 2), (4__α__,5__β__,10__α__)‐19‐hydroxy‐14‐oxoabieta‐8,13(15)‐dieno‐16,12‐lactone 19‐[2‐O‐(4‐hydroxy‐3,5‐dimethoxybenzoyl)‐β‐D‐glucopyranoside] (=curvifloruside C; 3), 19‐hydroxyjolkinolide E (4), 9‐oxo‐α‐bergamoten‐1‐yl β‐D‐glucopyranoside (=curvifloruside D; 5), 6‐deoxyharpagoside (=curvifloruside E; 6), and 6‐epiharpagoside (=curvifloruside F; 7). This is the first report on sesquiterpene and iridoid glycosides from the Phlogacanthus genus.