The new alkaloid oxytriphine, the parent of natural 2-oxazoline derivatives, has been isolated from the epigeal part of Oxytropis trichophysa; and its structure has been established as (5S)-(+)-2,5-diphenyl-2-oxazoline. (-)-N-Benzoyl-2-phenyl-2-hydroxyethylamine and benzoic acid have been detected in this plant for the first time. A hypothesis of the possible biogenetic interrelationship of the compounds isolated is put forward. © 1994, Plenum Publishing Corporation. All rights reserved.