Cyanocobalamin 7ฮฒ,8ฮฒ-lactone ; cyanocobalamin c,8-lactone,Coalpha-[alpha-(5,6-dimethylbenzimidazolyl)]-Cobeta-cyano-8beta-hydroxycobamic a,b,d,e,g-pentaamidec,8-gamma-lactone,Impurity in commercial preparation of Cyanocobalamin.,Cyanocobalamin Impurity