Feeding dried purple laver (nori) to vitamin B₁₂-deficient rats significantly improves vitamin B₁₂ status

Abstract

To clarify the bioavailability of vitamin B 12 in lyophylized purple laver (nori; Porphyra yezoensis), total vitamin B 12 and vitamin B 12 analogue contents in the laver were determined, and the effects of feeding the laver to vitamin B 12 -deficient rats were investigated. The amount of total vitamin B 12 in the dried purple laver was estimated to be 54´5 and 58´6 (SE 5´3 and 7´5 respectively) mg/100 g dry weight by Lactobacillus bioassay and chemiluminescent assay with hog intrinsic factor respectively. The purple laver contained five types of biologically active vitamin B 12 compounds (cyano-, hydroxo-, sulfito-, adenosyl-and methylcobalamin), in which the vitamin B 12 coezymes (adenosyl-and methylcobalamin) comprised about 60 % of the total vitamin B 12 . When 9-week-old vitamin B 12 -deficient rats, which excreted substantial amounts of methylmalonic acid (71´7(SE 20´2) mmol/d) in urine, were fed the diet supplemented with dried purple laver (10 mg/kg diet) for 20 d, urinary methylmalonic acid excretion (as an index of vitamin B 12 deficiency) became undetectable and hepatic vitamin B 12 (especially adenosylcobalamin) levels were significantly increased. These results indicate that vitamin B 12 in dried purple laver is bioavailable to rats.Vitamin B 12 deficiency: Purple laver: Urinary methylmalonate excretion: Hepatic vitamin B 12 content

Characterization and Bioavailability of Vitamin B12-Compounds from Edible Algae.

“…The silica gel 60 TLC and C18 reversed-phase HPLC patterns of the purified pink-colored compound were identical to those of authentic B12 (Table 2) , but not to those of the corrinoids inactive for humans , The purple layer contained five types of biologically active B12-compounds (CN-B12, OH-B12, SO3-B12 , AdoB12 and McB12), in which B12 coenzymes (AdoB12 and McBl2) comprised about 60% of the total B12 (16).…”

“…Edible algae are known to be rich in vitamins, minerals and dietary fiber (14). The B12 in various edi ble algae was assayed by IF-based competitive inhibition methods and/or the microbiological method using L. delbrueckii ATCC7830 (14)(15)(16) (Table 1). Although dried green (Enteromorpha sp.)…”

A simple, convenient method to synthesize cobalamins: synthesis of homocysteinylcobalamin, N-acetylcysteinylcobalamin, 2-N-acetylamino-2-carbomethoxyethanethiolatocobalamin, sulfitocobalamin and nitrocobalamin

“…Adenosylcobalamin, methylcobalamin and aquacobalamin (H 2 OCbl + ↔ HOCbl + H + ; pK a = 7.8) 6 are the major cobalamin metabolites isolated from biological samples. [7][8][9][10] Sulfitocobalamin (SO 3 Cbl − ) is also isolable from mammalian cells and foods, [9][10][11][12][13][14][15][16][17][18][19] and there are also reports of the isolation of nitrocobalamin (NO 2 Cbl) from biological sources. 11,20 Whether or not cyanocobalamin is truly 'naturally occurring' is controversial; some studies report small amounts of this derivative, especially in smokers.…”

“…Although both are isolable from biological samples, [11][12][13][14][15][16][17]20 and are well studied and structurally characterized, 23,29,38,43,[59][60][61][62][63][64][65][66][67][68][69] neither are commercially available. NO 2 Cbl is also of interest, since if nitrosylcobalamin (NOCbl) is formed in biological systems to any appreciable extent, NO 2 Cbl rather than NOCbl will be isolated after typical (aerobic) isolation and purification procedures.…”

Antioxidant Activity of the Phycoerythrobilin Compound Formed from a Dried Korean Purple Laver (Porphyra sp.) during in Vitro Digestion

“…Dried purple lavers contain various nutrients (Takenaka et al, 2001) and therapeutic compounds such as Porphyran (antitumor, antihypertensive, and antihyperlipidemic polysaccarides) (Takahashi et al, 2000), carnosine and anserine (antioxidant dipeptides) (Tamura et al, 1998), and phycoerythrin (pigment protein) (Fujiwara, 1961). Phycoerythrin, one of the phycobiliproteins which are the light-harvesting accessory pigments, is composed of phycoerythrobilin (chromophore, a linear tetrapyrrole compound) and apoprotein (Jiang et al, 1999).…”