Abstract: A new neolignan (7'E)-2',4,8-trihydroxy-3-methoxy-2,4'-epoxy-8,5'-neolign-7'-en-7-one (1) was isolated from the whole plants of Penthorum chinense Pursh, along with lupeol (2), betulinic acid (3), glyceryl monopalmitate (4), β-sitosterol (5), palmitic acid (6), ursolic acid (7), 2β,3β,23-trihydroxy-urs-12-ene-28-oic acid (8), glyceryl monolaurate (9), scopoletin (10), (–)syringaresinol (11), 9,9'-O-diferuloyl-(–)-secoisolariciresionl (12), pinocembrin (13), apigenin (14), kaempferol (15), luteolin (16), β-daucosterol (17), quercetin (18), 1-O-(β-D-glucopyranosyl)-(2S, 2'R, 3R,4E,8E)-2-(2'-hydroxyhexadecanoylamino)-4,8-octdecadiene-1,3-diol (19), gallic acid (20), pinocembrin-7-O-β-D-glucoside (21), and quercetin-3-O-β-D-glucoside (22). The structures of these compounds were elucidated on the basis of chemical and spectral evidence.

Key words: Gansu, neolignan, Penthorum chinense, pinocembrin, quercetin.