In our continuing search for biologically active compounds from indigenous South African flora, we have investigated Antizom angustifolia (Burch.) Miers ex Harv. (Menispermaceae). In the folk medicinal context, A. angustifolia was used against abdominal disorders (1). We report here the high yield isolation and characterization of sinoacutine, a morphinandienone-type alkaloid. Also isolated was p-sitosterol. These compounds have not been reported previously from this source. The slight anti-inflammatory activity of sinoacutine previously reported (2) is in agreement with our results (26% inhibition of phlogistic response at 300 mg/kg dose).