Synonyms: D-Ribitol,1-[4-(3-amino-1,2,5,6,6a,7-hexahydro-6,7-dimethyl-1-oxoimidazo[1,5-f]pteridinium-8-yl)phenyl]-1-deoxy-5-O-[5-O-[(1,3-dicarboxypropoxy)hydroxyphosphinyl]-a-D-ribofuranosyl]-, inner salt,[1(6S,6aR,7R),5(S)]-; Imidazo[1,5-f]pteridine, D-ribitol deriv.;5,10-Methenyl-5,6,7,8-tetrahydromethanopterin inner salt;Methenyltetrahydromethanopterin; Methenyltetrahydromethanopterin inner salt;Tetrahydromethenylmethanopterin inner salt