Isolation and identification of 5,10‐methenyl‐5,6,7,8‐tetrahydromethanopterin, a coenzyme involved in methanogenesis

The structure of the coenzyme involved in methanogenesis, which was known previously as ‘Yellow fluorescent compound’ or carboxy-5,6,7,8-tetrahydromethanopterin, has been elucidated by means of nuclear magnetic resonance and UV spectroscopy. The compound is now identified as 5,10-methenyl-5,6,7,8-tetrahydromethanopterin.