10.1039/c0nj00716a
The research focuses on the abiotic formation of uroporphyrinogen and coproporphyrinogen from acyclic reactants, which are key precursors in the biosynthesis of tetrapyrrole macrocycles like porphyrins. These macrocycles are essential in various bioenergetic processes and are considered crucial for the origin of life. The study aimed to identify plausible prebiotic routes for forming these macrocycles, particularly addressing the challenge of forming the pyrrole precursor, porphobilinogen (PBG). The researchers successfully demonstrated a structure-directed route where d-aminolevulinic acid (ALA) reacts with 5-methoxy-3-(methoxyacetyl)levulinic acid (1-AcOH) under anaerobic conditions in water at moderate temperatures and pH levels, yielding uroporphyrinogen. This process bypasses the need for PBG, a significant hurdle in prebiotic chemistry, and suggests a possible prebiotic pathway for the formation of tetrapyrrole macrocycles. The study also showed that a different precursor could lead to the formation of coproporphyrinogen without the intermediacy of uroporphyrinogen. The chemicals used in this process include ALA, 1-AcOH, and their decarboxy analogues, which under specific conditions, resulted in the formation of uroporphyrinogen and coproporphyrinogen, respectively.