Corrinoid
Corrinoids are a group of compounds based on the skeleton of corrin, a cyclic system containing four pyrrole rings similar to porphyrins. These include compounds based on octadehydrocorrin, which has the trivial name corrole.
The cobalamins are the best known members of the group. Other prominent examples include cobyrinic acid and its hexaamide cobyric acid; cobinic acid and its hexaamide cobinamide; cobamic acid and cobamide.
Compounds containing the "Cob-" prefix are cobalt derivatives, and may include an oxidation state, as in "Cobalamin". When cobalt is replaced by another metal or hydrogen, the name changes accordingly, as in ferrobamic acid or hydrogenobamic acid.
