Ly1cogladines A-H, fawcettimine-type Lycopodium alkaloids from Lycopodium complanatum var. glaucum Ching.

Five new fawcettimine-type alkaloids ( 1 – 5 ) and three new natural products ( 6 – 8 ), along with four known analogues, fawcettimine ( 9 ), fewcettidine ( 10 ), lycopoclavamine B ( 11 ), and lycopladine B ( 12 ), were isolated from the whole plant of Lycopodium complanatum var. glaucum Ching. The structures of lycogladines A-H ( 1 – 8 ) were determined based on HRESIMS, 1D and 2D NMR spectroscopic analysis, as well as single-crystal X-ray diffraction. Compound 1 possesses a new ring system that is formed through the linkage of C-13- O C-2, which is rarely present in Lycopodium alkaloids (LAs). Compounds 1 – 8 were tested for their β -site amyloid precursor protein (APP)-cleaving enzyme 1 (BACE1) and acetylcholinesterase (AChE) inhibitory activities. [ABSTRACT FROM AUTHOR]