title: Elucidation of the structure of methanopterin, a coenzyme from Methanobacterium thermoautotrophicum, using two-dimensional nuclear-magnetic-resonance techniques.
abstract: Methanopterin is a coenzyme involved in methanogenesis. From 2 kg wet cells of Methanobacterium thermoautotrophicum about 35 mumol methanopterin were isolated. The structure of this compound was elucidated by various two-dimensional nuclear-magnetic-resonance techniques. Methanopterin was identified as N-[1'-(2"-amino-4"-hydroxy-7" - methyl-6"- pteridinyl) ethyl]-4-[2',3',4',5'- tetrahydroxypent-1'- yl (5' leads to 1") O-alpha-ribofuranosyl-5"-phosphoric acid] aniline, in which the phosphate group is esterified with alpha-hydroxyglutaric acid. The molecular formula of the sodium salt of methanopterin at pH 7.0 is C30H38O16N6PNa3 X chiH2O (chi is about 4). The anhydrous sodium salt of methanopterin has a molecular mass of 838.60 Da and the molar absorption coefficient at 342 nm is 7.4 mM-1 cm-1 at pH 7.0.
mesh_terms: D055598:Chemical Phenomena; D002621:Chemistry; D003067:Coenzymes / Q000302:isolation & purification; D019605:Euryarchaeota / Q000201:enzymology*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D011522:Protons; D011622:Pterins / Q000302:isolation & purification*
chemical_list: D003067:Coenzymes; D011522:Protons; D011622:Pterins; C036686:methanopterin