Abstract
Three novel friedelane triterpenes, monospermonal, monospermonol and monospermondiol, along with six known friedelanes, 3-oxofriedelane, 3-oxofriedelan-28-al, 3,12-dioxofriedelane, 3-oxo-28-hydroxyfriedelane, 3-oxo-11β-hydroxyfriedelane, 3-oxo-12α-hydroxyfriedelane and an oleanane triterpenoid, 3β-hydroxyolean-12-ene, were isolated from the stems of Celastrus monospermus Roxb. The structures of novel compounds, monospermonal, monospermonol and monospermondiol, were identified as 3,12-dioxofriedelan-28-al, 3,12-dioxo-28-hydroxyfriedelane and 3-oxo-12α,28-dihydroxyfriedelane, respectively by spectroscopies including 2D NMR methods. These nine friedelane-type triterpenes were tested for antimicrobial activity against luminescent bacterium Photobacterium leiognathi N1 that had been isolated from “glowing” fish meat. Monospermonal and monospermonol showed moderate activity.