Tirucallane Triterpenoid Saponins from Munronia delavayi Franch

Four new tirucallane triterpenoid saponins, named munronosides I–IV ( 2 – 5 ), along with three known triterpenoids, sapelin B ( 1 ), melianodiol, and (3 β )‐22,23‐epoxytirucall‐7‐ene‐3,24,25‐triol, were isolated from the EtOH extract of the whole plants of Munronia delavayi Franch by chromatographic methods. On the basis of spectroscopic evidences, the structures of 2 – 5 were elucidated as (20 S ,23 R ,24 S )‐21,25‐epoxy‐29‐{{ O ‐ β ‐d‐ glucopyranosyl‐(1→3)‐ O‐ [ α ‐l‐ rhamnopyranosyl‐(1→6)]‐ β ‐d‐ glucopyranosyl}oxy}‐23,24‐dihydroxytirucall‐7‐ene‐3,21‐dione ( 2 ), (3 β ,20 S ,23 R ,24 S )‐21,25‐epoxy‐29‐{{ O ‐ β ‐d‐ glucopyranosyl‐(1→3)‐ O‐ [ α ‐l‐ rhamnopyranosyl‐(1→6)]‐ β ‐d‐ glucopyranosyl}oxy}‐3,23,24‐trihydroxytirucall‐7‐en‐21‐one ( 3 ), (20 S ,23 R ,24 S )‐24‐(acetyloxy)‐21,25‐epoxy‐29‐{{ O ‐ β ‐d‐ glucopyranosyl‐(1→3)‐ O‐ [ α ‐l‐ rhamnopyranosyl‐(1→6)]‐ β ‐d‐ glucopyranosyl}oxy}‐23‐hydroxytirucall‐7‐ene‐3,21‐dione ( 4 ), and (3 β ,20 S ,23 R ,24 S )‐24‐(acetyloxy)‐21,25‐epoxy‐29‐{{ O ‐ β ‐d‐ glucopyranosyl‐(1→3)‐ O‐ [ α ‐l‐ rhamnopyranosyl‐(1→6)]‐ β ‐d‐ glucopyranosyl}oxy}‐3,23‐dihydroxytirucall‐7‐en‐21‐one ( 5 ).