A new alkaloid identified as 3beta,6beta-ditigloyloxynortropane as 3beta,7beta-ditigloyloxynortropane, 4-hydroxyhygrinic acid, methylecgonidine and tropacocaine have been isolated from the leaves of Erythroxylum argentinum. The new structure was established by means of spectroscopic techniques. Four other species E. deciduum, E. microphyllum, E. pelleterianum and E. cuneifolium collected in the state of Rio Grande do Sul were screened for methylecgonidine and tropacocaine by CG/MS. Two of these plants contain tropacocaine and two contain methylecgonidine. GC/MS analysis of all 5 species for cocaine proved fruitless. The chemotaxonomic significance of these results is discussed.