Beta-3-Carbolines have been known to science since the isolation of harmaline in 1847, followed a few years later by the isolation of harmine. The struture elucidation of both compounds was accom pulished by Manske in 1927 and their total synthesis was published by Spath and Lederer in 1930. In spite of their long history, many aspects of the biochemistry and pharmacology of 3-beta-carboline derivatives remain poorly understood. Sinee the discovery in 1958 th at harmaline and related derivatives are competitive, reversible inhibitors of MAO, there has been a resurgence of interest in beta-3-carbolines.