Lyconadins C and F, new Lycopodium alkaloids from Lycopodium complanatum

Abstract New Lycopodium alkaloids, lyconadins C ( 1 ) and F ( 2 ), were isolated from the club moss Lycopodium complanatum . Lyconadin C ( 1 ) is a new C 16 N 2 -type Lycopodium alkaloid possessing unique fused-tetracyclic ring system consisting of a cycloheptene ring fused to a decahydroquinoline and pyridone rings. Lyconadin F ( 2 ) possesses a primary amide moiety in its molecular, which is the first example of Lycopodium alkaloids. Biogenetically, lyconadins C ( 1 ) and F ( 2 ) might be related to lyconadins A ( 4 ) and B ( 5 ). The structures and relative stereochemistry of 1 and 2 were elucidated on the basis of spectroscopic data. The absolute stereochemistry of 2 was elucidated by chemical correlations with lyconadin B ( 5 ) through hemiaminal form of lyconadin F ( 3 ).