title: Chemical evolution from hydrogen cyanide: photochemical decarboxylation of orotic acid and orotate derivatives.
abstract: Irradiation of solutions at pH 7 to pH 8.5 of orotic acid, orotidine, and orotidine 5'-phosphate with light at 254 nanometers yields the corresponding uracil derivative via the singlet excited state. This reaction completes a plausible prebiotic synthesis of uracil and its derivatives starting from HCN as the only carbon source.
mesh_terms: D003653:Decarboxylation; D006856:Hydrogen Cyanide; D009963:Orotic Acid / Q000031:analogs & derivatives; D010777:Photochemistry; D012265:Ribonucleotides; D014498:Uracil / Q000138:chemical synthesis; D014529:Uridine / Q000031:analogs & derivatives / Q000138:chemical synthesis; D014542:Uridine Monophosphate / Q000138:chemical synthesis
chemical_list: D012265:Ribonucleotides; D006856:Hydrogen Cyanide; D014498:Uracil; D009963:Orotic Acid; C008714:orotidine; D014542:Uridine Monophosphate; D014529:Uridine