Synonyms: Cobinamidecyanide, ester with guanosine 5'-pyrophosphate, inner salt (7CI); Cobinamide,cyanide hydroxide, monoester with guanosine 5'-(trihydrogen pyrophosphate),inner salt (8CI); Cobinamide, cyanide, monoester with guanosine 5'-(trihydrogendiphosphate), inner salt; Cobalamin y-1