title: Levels of pyrroloquinoline quinone in various foods.
abstract: The levels of free pyrroloquinoline quinone (PQQ) in various foods were examined by the use of gas chromatography-mass spectrometry. PQQ was extracted from the samples, after addition of [U-13C]PQQ as internal standard, with n-butanol and Sep-Pak C18 cartridges. After derivatization of PQQ with phenyltrimethylammonium hydroxide, molecular peaks at m/z 448 and 462 were used for detection of PQQ and [U-13C]PQQ respectively, by selected ion monitoring. Free PQQ could be detected in every sample in the range 3.7-61 ng/g or ng/ml. Since its levels in human tissues and body fluids are 5-10 times lower than those found in foods, it is probable that PQQ existing in human tissues is derived, at least partly, from the diet.
authors.affiliation: Department of Legal Medicine, Showa University School of Medicine, Tokyo, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Kumazawa
authors.forename: K
authors.initials: K
authors.lastname: Sato
authors.forename: H
authors.initials: H
authors.lastname: Seno
authors.forename: A
authors.initials: A
authors.lastname: Ishii
authors.forename: O
authors.initials: O
authors.lastname: Suzuki
mesh_terms: D003067:Coenzymes / Q000032:analysis*; D005504:Food Analysis; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D045542:PQQ Cofactor; D015363:Quinolones / Q000032:analysis*; D012015:Reference Standards
chemical_list: D003067:Coenzymes; D015363:Quinolones; D045542:PQQ Cofactor