Wiktionary
tetrahydromethanopterin
n. (context organic chemistry English) A coenzyme in methanogenesis, related to tetrahydrofolic acid.
Wikipedia
Tetrahydromethanopterin
Tetrahydromethanopterin (THMPT, ) is a coenzyme in methanogenesis. It is the carrier of the C1 group as it is reduced to the methyl level, before transferring to the coenzyme M.
Tetrahydrosarcinapterin (THSPT, ) is a modified form of THMPT, wherein a glutamyl group linked to the 2-hydroxy glutaric acid terminus.