Characterization of Corrinoid Compounds in the Edible Cyanobacterium <i>Nostoc flagelliforme</i> the Hair Vegetable

Abstract

Vitamin B 12 contents in the edible cyanobacterium Nostoc flagelliforme, also known as hair vegetable, were assayed using a microbiological method. We detected high vitamin B 12 contents in samples of naturally grown cells (109.2 ± 18.5 μg/100g dry weight) and cultured cells (120.2 ± 53.6 μg/100g dry weight). However, commercially available hair vegetable samples, which comprised fake substitutes and Nostoc, had variable contents (4.8 -101.6 μg/100g dry weight) because concomitant fake items contain very low vitamin B 12 contents. To evaluate whether natural and cultured N. flagelliforme samples contained vitamin B 12 or pseudovitamin B 12 , corrinoid compounds were purified and identified as pseudovitamin B 12 (approximately 72%) and vitamin B 12 (approximately 28%) using silica gel 60 TLC bioautography and LC/MS. The results suggested that N. flagelliforme contains substantial amounts of pseudovitamin B 12 , which is inactive in humans.

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.…”

Lipophilic and Hydrophilic Compounds from Arthrospira platensis and Its Effects on Tissue and Blood Cells—An Overview

“…High levels of vitamin B12 are described in the nutritional labels of dietary supplements that contain edible cyanobacteria, such as Spirulina , Aphanizomenon , and Nostoc [ 93 ]. However, although substantial amounts of vitamin B12 were detected in these commercially available supplements, using a microbiological vitamin B12 assay method, these supplements often contained large amounts of pseudovitamin B12 (Coα-[α-(7-adenyl)]-Coβ-cyanocobamide) [ 94 , 95 , 96 , 97 , 98 , 99 ], which is biologically inactive in humans, and only 17% were identified as dimethylbenzimidalylcobamide, also known as vitamin B12 [ 98 , 100 ]. Therefore, edible cyanobacteria and their products are only of limited use as sources of vitamin B12 for vegetarians; see the statement of the American Dietetic Association [ 100 ].…”

A cobalt concentration sensitive Btu-like system facilitates cobalamin uptake in Anabaena sp. PCC 7120

“…Both pseudocobalamin and cobalamin biosynthesis has been demonstrated in cyanobacteria, although several reports of cobalamin are from non-axenic material [ 28 ] or material without indication of the culture purity [ 22 , 29 – 31 ]. Consistently, Anabaena has genes encoding proteins involved in the synthesis of such metabolites [ 22 ].…”