Phytochemical investigation on the rhizomes of Sinomenium acutum led to the isolation of new alkaloids sinomacutines A E (1-5), and cephalonine-2-O-beta-n-glucopyranoside (6), along with known tetrahydroisoquinoline alkaloids (7-9). Among them, sinomacutines A C were new bistetrahydroisoquinoline alkaloids with morphinane-proaporphine and morphinane-benzyltetrahydroisoquinoline types, and coupled with unique C-CH2-N unit. Their structures with absolute configuration were elucidated on the basis of 1D and 2D NMR, and ECD spectra analysis. The new compounds were evaluated for their anti-inflammatory and cytotoxic activities, and sallisonine B (2) showed moderate ability to inhibit NO production of LPS-stimulated RAW264.7 macrophages, as well as sallisonine A (1) showed weak inhibitory effects against five cancer cell lines. (C) 2014 Elsevier Ltd. All rights reserved.