Methylcobalamin is a cobalamin, a form of vitamin B₁₂. It differs from cyanocobalamin in that the cyano group at the cobalt is replaced with a methyl group. Methylcobalamin features an octahedral cobalt(III) centre and can be obtained as bright red crystals. Methylcobalamin binds with an intrinsic factor and form a complex which is absorbed in distal ileum. Its half life is 6 days. Surprisingly, methylcobalamin and adenosylcobalamin are relatively stable in neutral aqueous solution in the dark and can be heated for 20 min at 100 °C. Adenosylcobalamin is unstable under acidic and alkaline conditions, whereas methylcobalamin is stable in the presence of dilute acid or alkali.
Molar Mass: 1,344.4 g/mol