Determination of individual vitamin B(6) compounds based on enzymatic conversion to 4-pyridoxolactone.
A determination method for individual natural vitamin B(6) compounds was developed. The vitamin B(6) compounds were specifically converted into 4-pyridoxolactone (PAL), a highly fluorescent compound, through a combination of enzymatic reactions and HCl-hydrolysis. PAL was then determined by HPLC. Pyridoxal was completely oxidized to PAL with pyridoxal 4-dehydrogenase (PLDH). Pyridoxine and pyridoxamine were totally converted into PAL through a coupling reaction involving pyridoxine 4-oxidase and PLDH, and one involving pyridoxamine-pyruvate aminotransferase and PLDH, respectively. The 5'-phosphate forms and pyridoxine-beta-glucoside were hydrolyzed with HCl, and then determined as their free forms. Pyridoxine 5'-phosphate and pyridoxine-beta-glucoside were not separately determined here. Three food samples were analyzed by this method.
Nishimura
Saki
S
Department of Bioresources Science, Faculty of Agriculture, Kochi University, Kochi, Japan.
Nagano
Sayaka
S
A Crai
Chan
C
Yokochi
Nana
N
Yoshikane
Yu
Y
Ge
Fei
F
Yagi
Toshiharu
T
D000429:Alcohol Oxidoreductases / Q000737:chemistry*; D000818:Animals; D002212:Capsicum; D002645:Chickens; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D005504:Food Analysis / Q000379:methods*; D005737:Garlic; D005960:Glucosides / Q000032:analysis / Q000737:chemistry; D006851:Hydrochloric Acid / Q000737:chemistry; D006868:Hydrolysis; D011735:Pyridoxic Acid / Q000031:analogs & derivatives* / Q000032:analysis / Q000138:chemical synthesis; D011736:Pyridoxine / Q000031:analogs & derivatives / Q000032:analysis / Q000737:chemistry; D013997:Time Factors; D000637:Transaminases / Q000737:chemistry*; D025101:Vitamin B 6 / Q000032:analysis / Q000737:chemistry; D014803:Vitamin B Complex / Q000032:analysis* / Q000737:chemistry
D005960:Glucosides; D014803:Vitamin B Complex; C022945:5'-O-(glucopyranosyl)pyridoxine; C036509:4-pyridoxic acid lactone; D011735:Pyridoxic Acid; D025101:Vitamin B 6; D000429:Alcohol Oxidoreductases; C042642:pyridoxal dehydrogenase; C487815:pyridoxine 4-oxidase; D000637:Transaminases; C022494:pyridoxamine-pyruvate transaminase; D011736:Pyridoxine; D006851:Hydrochloric Acid