ABSTRACT
A set of chemical reactions is proposed to account for the formation of pyridoxal phosphate, Vitamin B6, from a primeval atmosphere composed of cyanoacetylene, diacetylene, carbon monoxide, hydrogen, water, and a phosphoric acid. The reactions have been shown to be feasible from the overall enthalpy changes in the ZKE approximation at the HF and MP2/6-31G* level.
Subject(s)
Computer Simulation , Pyridoxal Phosphate/chemical synthesis , Vitamin B 6/chemical synthesis , Acetylene/analogs & derivatives , Acetylene/chemistry , Carbon Monoxide/chemistry , Evolution, Chemical , Hydrogen/chemistry , Models, Chemical , Molecular Structure , Nitriles/chemistry , Phosphoric Acids/chemistry , Pyridoxal Phosphate/chemistry , Thermodynamics , Vitamin B 6/chemistry , Water/chemistryABSTRACT
A set of chemical reactions is postulated to account for the formation of the macrocyclic porphin structure, basic to the pyrrole derivatives chlorophyll, protoporphyrin, heme and bilirubin, important in photosynthesis, respiration and digestion. A set of equations is given for the prebiotic synthesis of porphin derivatives from the simple molecules; cyanoacetylene, diacetylene, carbon monoxide and ammonia that have been detected in space. A number of isomers of hydrogenated porphin arise which may lose hydrogen to give ultimately porphin and its dehydrogenated derivative. The reactions, while not unique, provide a pathway which has been shown to be feasible from the overall enthalpy changes in the ZKE approximation at the HF and MP2/6-31G* level.
