A New Fawcettimine-Related Alkaloid from Lycopodium japonicum

A new fawcettimine-related alkaloid, 17α-methyllycoflexine (1), together with 14 known analogues, was isolated from the whole plants of Lycopodium japonicum Thunb. Their structures were established by extensive spectroscopic analysis, including NMR and HR-EI-MS experiments. Compound 1 is the second example of derivatives of lycoflexine with an unprecedented additional methyl group at C-17. All the isolated alkaloids were assayed for α-glucosidase inhibitory activity. Only lycodine showed weak α-glucosidase inhibitory activity, whereas the other alkaloids showed no activity.