<jats:p>The alkaloids of Alseodaphne archboldiana (Allen) Kostermans of the family Lauraceae are 1-benzyl-1,2,3,4-tetrahydroisoquinolines, and they have been shown to be (-)-N-norarmepavine, (+)-reticuline, and both (+) and (-)-coclaurine. (+)-Coclaurine isolated from Xylopia papuana has been shown to be close to optical purity, and comparison with it indicates that the mixture of coclaurine optical isomers from A. archboldiana consists of (+)-coclaurine and (-)-coclaurine in the approximate ratio 3 : 1. Useful structural information can be derived from the N.M.R. spectra of N-acetyl compounds prepared from coclaurine and N-norarmepavine.