The papaverrubine alkaloids and their N‐methyl derivatives are widely distributed in the genus Papaver. They have a number of interesting structural and stereochemical characteristics. A new alkaloid of this general class has now been isolated from opium. It has been characterized by means of NMR and mass spectrometry and by chemical conversions to known compounds. Copyright © 1968 Wiley‐Liss, Inc., A Wiley Company