Characterization of Corrinoid Compounds in the Edible Cyanobacterium Nostoc flagelliforme the Hair Vegetable

Vitamin B12 contents in the edible cyanobacterium Nostoc flagelliforme, also known as hair vegetable, were assayed using a microbiological method. We detected high vitamin B12 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 B12 contents. To evaluate whether natural and cultured N. flagelliforme samples contained vitamin B12 or pseudovitamin B12, corrinoid compounds were purified and identified as pseudovitamin B12 (approximately 72%) and vitamin B12 (approximately 28%) using silica gel 60 TLC bioautography and LC/MS. The results suggested that N. flagelliforme contains substantial amounts of pseudovitamin B12, which is inactive in humans.