Purification and Characterization of Corrinoid-Compounds from the Dried Powder of an Edible Cyanobacterium, Nostoc commune (Ishikurage)

Abstract

Vitamin B₁₂ content (98.8±5.6 μg/100 g dry weight) of an edible cyanobacterium, Nostoc commune (Ishikurage) was determined by the Lactobacillus delbrueckii ATCC 7830 microbiological method. Bioautography with vitamin B₁₂-dependent Escherichia coli 215 indicated that N. commune contained two (main and minor) corrinoid-compounds. These corrinoid-compounds were purified to homogeneity from the dried algal cells and characterized. The main and minor purified corrinoid-compounds were identified as pseudovitamin B₁₂ and vitamin B₁₂, respectively, on the basis of silica gel 60 TLC, C18 reversed-phase HPLC, ¹H NMR spectroscopy, and UV-visible spectroscopy. These results suggest that the bacterial cells are not suitable for use as a vitamin B₁₂ source, especially in vegetarians.