Pseudovitamin B-12 is the predominant cobamide of an algal health food, spirulina tablets

The vitamin B-12 concentration of an algal health food, spirulina (Spirulin a sp.) tablets, was determined by both Lactobacillus leichmannii ATCC 7830 microbiological and intrinsic factor chemiluminescence methods. The values determined with the microbiological method were similar to 6-9-fold greater in the spirulina tablets than the values determined with the chemiluminesc ence method. Although most of the vitamin B-12 determined with the microbio logical method was derived from various vitamin B-12 substitutive compounds and/or inactive vitamin B-12 analogues, the spirulina contained a small am ount of vitamin B-12 active in the binding of the intrinsic factor. Two int rinsic factor active vitamin B-12 analogues (major and minor) were purified from the spirulina tablets and partially characterized. The major (83%) an d minor (17%) analogues were identified as pseudovitamin B-12 and vitamin B -12, respectively, as judged from data of TLC, reversed-phase HPLC, H-1 NMR spectroscopy, ultraviolet-visible spectroscopy, and biological activity us ing L. leichmannii as a test organism and the binding of vitamin B-12 to th e intrinsic factor.