| Phytochemical investigations of four members of the genus Magnolia (family Magnoliaceae) were performed to provide lignans and sesquiterpene lactones. The aerial parts of the rare Louisiana native M. pyramidata afforded eight new neolignans with a novel skeleton, pyramidatin A to H. Leaves of M. virginiana provided the known sesquiterpene lactones parthenolide and costunolide as well as the new costunolactol and costunolactol dimer. An annual study of the leave constituents of M. virginiana illustrated that native M. virginiana only produces sesquiterpene lactones but transferred M. virginiana, possibly a northern variety, produces only lignans. The leaves of M. soulangiana gave five known lignans and neolignans, galgravin, veraguensin, futoenone, denudatone and denadatin A. The leaves of M. acuminata provided five burchellin-type neolignans and one new neolignan, acuminatin B. Detailed structural elucidations of all known and new compounds were performed by application of spectroscopic methods. A chemical study of roots of blue-flowered lettuce, Lactuca floridana (family Asteraceae), gave the known guaianolides 8-acetyllactucin, 8-desoxylactucin and 8-acetyl-11... |
