Abstract
A vitamin B12-like substance, tentatively called X factor, was isolated from an animal feed supplementing B12. From the results of paper electrophoresis, absorption spectra, microbiological activities, precursor effect in B12 biosynthesis. X factor was shown to have a structure nearly related to cobinamide. Though a number of B12-like substances have so far been isolated, such as from sewage and culture medium of Propionibacterium shermannii (Bernhauer) and from supernatant liquor distiller's waste digester and human excreta treatment plant (Shimizu), but the isolation of such large quantities of cobinamide has not been reported. Especially, the method adopted by the authors using P-cellulose is very simple and the separation is satisfactory. It can be safely recommended for preparation of cobinamide.
TABLE III Effect of X Factor as a Precursor in Cobammide Biosynthesis
It is not clear whether this cobinamide has been present in the feed supplement or has released from cobamide during purification procedures. If the former is the case, the significance as an intermediate in cobamide biosynthesis must be considered. Studies on the mechanism of cobamide biosynthesis using X factor and the promotion of cobamide production by culture are the problems under way. As paper electrophoresis of X factor in a neutral medium resulted often in separation of several spots and that in an acidic medium whithout cyanide resulted in appearance of yellow spot, X factor may not be a simple compound.
