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

Abstract

Vitamin B 12 contents in the e dibl e 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.