Definition: A group of compounds with the heterocyclic ring structure of benzo(c)pyridine. The ring structure is characteristic of the group of opium alkaloids such as papaverine. (From Stedman, 25th ed)
McN 5652 [ McN 5652-X-68,McN-5652,McN-5652-Z,McN-5652-Z-68 ] only McN 5662-X-68 (6S,10R-enantiomer) is biologically active; structure given in first source