Florisil chromatography of mother liquor residues from which chelerythine, protopine and sanguinarine had been removed yielded crystals of a colorless base (1), mp 154-155°, R_f 0.72 (Si gel; EtOAc); NMR (CDCl3): s,2.61δ(3H); s, 3.85 (3H); s, 3.92 (3H); s, 3.96 (3H); s, 4.03 (3H); s, 4.11 (3H); s, 4.26 (2H); m, 7.0-7.7 (5H); UV (MeOH): 238 nm (log∈4:21), 262 (4.38), 275 (4.42), 325 (4.22); MS: m/e 395 (30%), 394 (100), 379 (20). Anal. Calcd for C23H25NO3: C, 69.86; H,6.37; N, 3.54. Found: C, 69.29; H, 6.16; N, 3.15%. A hot soln of 10 mg (1) in 6 ml aq. HOAc was treated with 100 mg mercuric acetate and heated for 2 hr: The cooled mixture was filtered and evaporated to dryness to leave a residue of sanguilutine identical with an authentic sample isolated from the same plant. These data show the unknown to be dihydrosanguilutine (1), a previously unreported alkaloid.