Two new vitamin B-12 factors from sewage sludge containing 2-methylsulfinyladenine or 2-methylsulfonyladenine as base component.

Two hitherto unknown vitamin B-12 factors were isolated from sewage sludge. They were degraded with cerous hydroxide to cobinamide and the corresponding nucleoside. The nucleosides were further split with dilute hydrochloric acid to the bases and D-ribose. The structure of the two bases was found to be 2-methylsulfinyladenine and 2-methylsulfonyladenine. This was revealed by mass, infrared and nuclear magnetic resonance spectroscopy, and by comparison with the synthetic compounds. On addition of the synthetic bases to fermentations with Propionibacterium acidi-propionici the vitamin B-12 factors containing the corresponding base were formed. They were identical with the 2-methylsulfonyladenylcobamide and 2-methylsulfonyladenylcobamide originally isolated from sewage sludge.