Chemical and spectral studies of lunarine (1) main alkaloid from Honesty, Lunaria biennis Moench, Crucifereae, have been completed. The stereochemistry of lunarinols I and II, obtained by reduction of the ketone function of lunarine, has been determined through a comparative study of the NMR spectra of their derivatives and of those of corresponding alcohols in the Pummerer's ketone series. Photoisomerization of the cinnamic system of lunarine has been disclosed. Structure of satellite alkaloids of lunarine have been established. © 1972.