International Union of Pure and Applied Chemistry
International Union of Biochemistry

Joint Commission on Biochemical Nomenclature (JCBN)

Nomenclature of Tetrapyrroles

(Recommendations 1986)

(Supersedes provisional version published 1979)

World Wide Web version prepared by G. P. Moss

School of Physical and Chemical Sciences, Queen Mary University of London,
Mile End Road, London, E1 4NS, UK

The recommendations in this version are identical to those in the published document prepared for publication by G. P. Moss (see Eur. J. Biochem., 1988, 178, 277-328; Pure Appl. Chem., 1987, 59, 779-832; Biochemical Nomenclature and Related Documents, 2nd edition, Portland Press, 1992, pages 278-329. Copyright IUBMB and IUPAC]. Footnotes in the printed text have been located as notes after the relevant paragraph or example. Any comments, corrections or suggestions for a future edition should be e-mailed to In setting up the World Wide Web version some errors have been detected. The changes have been marked by error details which is a link to details of the change and where it applies. For problems in converting the text into a World Wide Web version see the IUPAC home page. A PDF of the printed version is available.

Members of Expert Panel: R. Bonnett (UK, Convenor); S. Aronoff (Canada); A. R. Battersby (UK); A. Eschenmoser (Switzerland); H. Falk (Austria); A. Gossauer (Switzerland); H. H. Inhoffen (FRG); A. H. Jackson (UK); D. A. Lightner (USA); S. Onishi (Japan); J. M. Ribo (Spain); C. Rimington (Norway); M. S. Stoll (UK).

Synopsis - In the revised recommendations two new trivial names (isobacteriochlorin and sirohydrochlorin) are defined. Isobacterlochlorin is 2,3,7,8-tetrahydroporphyrin and is isomeric with bacteriochlorin. An example of an isobacteriochlorin is sirohydrochlorin, an intermediate in the biosynthesis of corrinolds. 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.


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