The vitamin B12 group; presence of 2-methyl purines in factors A and H and isolation of new factors.
D006397:Hematinics; D011687:Purines; D014805:Vitamin B 12 / Q000031:analogs & derivatives
D006397:Hematinics; D011687:Purines; D014805:Vitamin B 12; C030985:purine
VITAMIN B12/derivatives