Lignans with (N, N-diethyl)methyl amino group from Buxus rugulosa

Buxrugulosides A–E, four lignan glycosides ( 1–4 ) and a protocatechuate derivative ( 5 ) featuring a rare (N, N-diethyl)methyl amino group at aromatic rings, were obtained from the aerial parts of Buxus rugulosa, which is famous for treating coronary heart disease. Their structures including absolute configurations were elucidated by HRMS, 1D and 2D NMR, and by comparing their CD data with previous reports. Compound 1 was a rare sesquilignan, and all of these compounds were the first example of lignans with (N, N-diethyl)methyl amino group.