3,4-Secocycloartane Triterpenoids from the Cones of Pseudolarix amabilis

Four new 3,4-secocycloartane triterpenoids, pseudolactones A-D (1-4), were isolated from the ethanol extract of the cones of Pseudol arixamabilis. Their structures were established by extensive 1D- and 2D-NMR experiments. The cones of P. arixamabilis are enriched in the ring-expanded or cleaved cycloartane triterpenoids. This work provides new insight into cycloartane triterpenoids from the cones of P. arixamabilis.