The biosynthesis of vitamin B 12 : a study by  13 C magnetic resonance spectroscopy.
D002247:Carbon Isotopes; D055598:Chemical Phenomena; D002621:Chemistry; D007982:Levulinic Acids / Q000138:chemical synthesis / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy; D008314:Malonates; D011424:Propionibacterium / Q000378:metabolism*; D014805:Vitamin B 12 / Q000096:biosynthesis*
D002247:Carbon Isotopes; D007982:Levulinic Acids; D008314:Malonates; D014805:Vitamin B 12