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.