Nomenclature of tetrapyrroles

Abstract

In the revised recommendations two new trivial names (isobacteriochlorin and sirohydrochlorin) are defined. Isobacteriochlorin is 2,3,7,8‐tetrahydroporphyrin and is isomeric with bacteriochlorin. An example of an isobacteriochlorin is sirohydrochlorin, an intermediate in the biosynthesis of corrinoids. The names of linear tetrapyrroles are amended. The name bilin is now restricted to the fully oxidized parent, and less oxidized forms are named bilane, bilene, and biladiene. Names are now provided for the analogous dipyrrole system based on the parent dipyrrin. Tables are provided to show the structures of the more commonly encountered compounds using the Fischer system for denoting isomers (the fifteen isomers of mesoporphyrin defined by Fischer, and some isomers of biliverdin). Experience has shown that these names continue to be useful because of their brevity.