Purification and Characterization of a Corrinoid-Compound in an Edible Cyanobacterium Aphanizomenon flos-aquae as a Nutritional Supplementary Food

Abstract

The vitamin B12 concentration of the dried cells of Aphanizomenon flos-aquae was determined by both microbiological method with Lactobacillus delbrueckeii ATCC7830 and chemiluminescence method with intrinsic factor. The Aphanizomenon cells contained 616.3 +/- 30.3 micro g (n = 4) of vitamin B12 per 100 g of the dried cells by the microbiological method. The values determined with the chemiluminescence method, however, were only about 5.3% of the values determined by the microbiological method. A corrinoid-compound was purified from the dried cells and characterized. The purified corrinoid-compound was identified as pseudovitamin B12 (an inactive corrinoid-compound for humans) by silica gel 60 TLC, C18 reversed-phase HPLC, ultraviolet-visible spectroscopy, and 1H NMR spectroscopy. The results suggest that the Aphanizomenon cells are not suitable for use as a vitamin B12 source, especially in vegans.

Methyladeninylcobamide functions as the cofactor of methionine synthase in a Cyanobacterium, Spirulina platensis NIES‐39

“…Cells with a red tint were collected, washed twice with distilled water, and then stored at −80 °C until use. AdeCba was extracted and purified from the stored cells by a Sep‐pak Vac 20 cc (5 g) C 18 cartridge (Waters Corp. Milford, MA, USA), silica gel 60 TLC, and C 18 reversed‐phase HPLC as described previously [7]. The Rf value on silica gel 60 TLC and retention time on C 18 reversed‐phase HPLC of the purified compound coincided with those of an authentic cyanoadeninylcobamide or pseudovitamin B 12 (CN‐AdeCba).…”

Vitamin B12 among Vegetarians: Status, Assessment and Supplementation

“…In a pilot study, supplementation with Klamath microalgae ( Aphanizomenon flos-Aque ) improved Cbl status among 15 vegan subjects, assessed by serum Cbl and plasma HCY in a three-month open-label intervention [185]. Klamath contains about 32 μg/100 g of Cbl but Watanabe et al extracted only a pseudovitamin analog from Klamath [186]. Chlorella pyrenoidosa is a microalgae frequently used as a supplement [187].…”

Vitamin B12-Containing Plant Food Sources for Vegetarians

“…High levels of Vitamin B 12 are described in the nutritional labels of dietary supplements that contain edible cyanobacteria such as Spirulina , Aphanizomenon , and Nostoc . However, although substantial amounts of Vitamin B 12 were detected in these commercially available supplements using a microbiological Vitamin B 12 assay method, these supplements often contained large amounts of pseudovitamin B 12 [66,67,68,69,70,71] (Figure 3), which is biologically inactive in humans. Therefore, edible cyanobacteria and their products are not suitable for use as sources of Vitamin B 12 for vegetarians.…”