A novel pyrrolizidine alkaloid, 3'-acetylindicine-N-oxide {[1R-[1 alpha, 7(2R*, 3S*), 7 alpha beta]]-3-acetoxy-2-hydroxy-2-(1-methylethyl)-butanoic acid (2,3,5,7a-tetrahydro-1-hydroxy-1H-pyrrolizin-7-yl)methyl ester N-oxide}, was isolated from the twigs of Messerschmidia argentea, in addition to 3'-acetylindicine, indicine and its N-oxide. Structures of these alkaloids were determined by spectroscopic methods and from chemical evidence. Copyright (C) 1997 Elsevier Science Ltd