Six New Dammarane Triterpenoids from <i>Viburnum cylindricum</i>

Abstract

Abstract One new dammarane triterpenoid, cylindrictone A ( 1 ), as well as five new nor ‐dammarane triterpenoids cylindrictone B–F ( 2 – 6 ) were isolated from the leaves of Viburnum cylindrium , together with three known compounds 3 β ‐hydroxy‐hexanordammaran‐20‐one ( 7 ), 3 α ‐hydroxyoctanordammar‐12‐en‐17‐one ( 8 ), and neoalsogenin B ( 9 ). Their structures were identified by extensive NMR‐spectroscopic (especially 2D‐NMR) and mass‐spectrometric experiments, and the structure of 3 was further confirmed by a single‐crystal X‐ray analysis. The compounds exhibited no activity against human promyelocytic leukemia HL60 cell.