Pyrrolizidine alkaloids from Cynoglossum furcatum.

Two new pyrrolizidine alkaloids have been isolated from the roots of Cynoglossum furcatum. On the basis of chemical and spectroscopic evidence, structures of the compounds have been elucidated. They are lactodine (3), a monoster alkaloid and viridinatine (4), a pyrrolizidine diester alkaloid. The structure of lactodine is elucidated as 9-O-(-)lactyl heliotridine and viridinatine as 7-O-(-)viridifloryl echinatine.