6- (L-1,2,3-Trihydroxybutyl) -pterin

6- (L-1,2,3-Trihydroxybutyl) -pterin is a derivative of L-biopterin and is the oxidized form of tetrahydro-L-biopterin (BH4) as well as D-biopterin. Co-ingestion of 6- (L-1,2,3-Trihydroxybutyl) -pterin (0.5%) with the carcinogen 4-dimethylaminoazobenzene reduces the incidence of 4-dimethylaminoazobenzene-induced liver tumors in rats. 6- (L-1,2,3-Trihydroxybutyl) -pterin has been used as an internal standard for the LC-MS quantification of biopterin and neopterin in rat plasma.