title: Determination of quinonoid dihydrobiopterin by liquid chromatography and electrochemical detection.
abstract: Tetrahydrobiopterin (BH4) is a required cofactor for the hydroxylation of the amino acids phenylalanine, tyrosine and tryptophan. Quinonoid dihydrobiopterin (q-BH2) is the natural product of the oxidation of BH4 in these enzymatic reactions. This report describes a method based on liquid chromatography and electrochemical detection for the determination of q-BH2 in synthetic and biological samples. This methodology is used to study the electrochemistry of q-BH2 formed by oxidation of BH4 and in the hydroxylation of phenylalanine by phenylalanine hydroxylase.
mesh_terms: D000818:Animals; D001708:Biopterins / Q000031:analogs & derivatives / Q000032:analysis*; D002853:Chromatography, Liquid / Q000379:methods; D004563:Electrochemistry; D008099:Liver / Q000378:metabolism; D051379:Mice; D010084:Oxidation-Reduction; D011621:Pteridines / Q000032:analysis*
chemical_list: D011621:Pteridines; D001708:Biopterins; C017226:7,8-dihydrobiopterin