title: Trace levels of pyrroloquinoline quinone in human and rat samples detected by gas chromatography/mass spectrometry.
abstract: A detailed procedure for the assay of free pyrroloquinoline quinone (PQQ) in human and rat samples by gas chromatography/mass spectrometry (GC/MS) has been established with stable-isotopic PQQ as internal standard. PQQ was extracted from the samples, after addition of the internal standard, with butanol under acid conditions and with 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 by selected ion monitoring, respectively. Trace amounts of free PQQ were detected in eight organs, plasma and urine of the human, and in three organs of the rat. The PQQ level was highest in the human spleen (5.9 +/- 3.4 ng/g tissue, followed by the pancreas and lung, and it was below detection limits for human brain and heart. Trace levels of PQQ were also found in rat small intestine, liver and testis. Our data are far below those measured by the redox cycling method of Gallop's group for human plasma, adrenal and urine.
authors.affiliation: Department of Legal Medicine, Hamamatsu University School of Medicine, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Kumazawa
authors.forename: H
authors.initials: H
authors.lastname: Seno
authors.forename: T
authors.initials: T
authors.lastname: Urakami
authors.forename: T
authors.initials: T
authors.lastname: Matsumoto
authors.forename: O
authors.initials: O
authors.lastname: Suzuki
mesh_terms: D000818:Animals; D001923:Brain Chemistry; D003067:Coenzymes / Q000032:analysis* / Q000097:blood / Q000652:urine; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D045542:PQQ Cofactor; D000644:Quaternary Ammonium Compounds; D015363:Quinolones / Q000032:analysis* / Q000097:blood / Q000652:urine; D051381:Rats; D017208:Rats, Wistar; D013154:Spleen / Q000737:chemistry
chemical_list: D003067:Coenzymes; D000644:Quaternary Ammonium Compounds; D015363:Quinolones; C001420:3-hydroxyphenyltrimethylammonium; D045542:PQQ Cofactor