title: Prebiotic 5-substituted uracils and a primitive genetic code.
authors.forename: S
authors.initials: S
authors.lastname: Black
mesh_terms: D000596:Amino Acids / Q000737:chemistry*; D003596:Cytosine / Q000737:chemistry; D005815:Genetic Code; D010455:Peptides / Q000138:chemical synthesis / Q000737:chemistry; D014498:Uracil / Q000031:analogs & derivatives* / Q000737:chemistry
chemical_list: D000596:Amino Acids; D010455:Peptides; D014498:Uracil; D003596:Cytosine