The insolubility of calcium phosphate in water is a significant stumbling block in the chemistry required for the origin of life. The discovery of alkyl phosphonic acids in the Murchison meteorite suggests the possibility of delivery of these water-soluble, phosphorus-containing molecules by meteorites or comets to the early Earth. This could have provided a supply of organic phosphorus for the earliest stages of chemical evolution; although probably not components of early genetic systems, phosphonic acids may have been precursors to the first nucleic acids. Here we report the synthesis of several phosphonic acids, including the most abundant found in the Murchison meteorite, by ultraviolet irradiation of orthophosphorous acid in the presence of formaldehyde, primary alcohols, or acetone. We argue that similar reactions might explain the presence of phosphonic acids in Murchison, and could also have occurred on the prebiotic Earth.

Please be advised that this information was generated on 2018-05-13 and may be subject to change.J M ol Evol (1997) Abstract. Phosphonic acids are the only phosphoruscontaining organic compounds detected in the Murchi son meteorite, We earlier described the synthesis of methyl-, hydroxy methyl-, and l-hydroxyethyl phos phonic acids using sodium phosphite as a source of phos phite radicals. We now show that ultraviolet irradiation of dilute aqueous solutions of acetylene in the presence of sodium phosphite leads to the synthesis of vinyl phos phonic acid. At neutral to basic pH, vinyl phosphonic acid reacts under photochemical conditions to produce phosphonoacetaldehyde and 2 -hydroxyethyl phosphonic acid as the major products, as well as smaller yields of 1-hydroxyethyl phosphonic acid, phosphonoacetic acid, and ethyl phosphonic acid. Of these products, phospho noacetaldehyde is particularly interesting as a potential precursor of prebiotic carbohydrate derivatives.

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Poly (Leu-Lys) was shown to assist the oligomerization of activated nucleotide diphosphates. Short oligomers of pdGp are formed in dilute solution. Activated oligomers can complex to the polypeptide and polymerize to form longer oligomers. Oligomers up to the 18-mer can be obtained under these conditions from 1 x 10 .3 M ImpdGpIm in the absence of a preformed polynucleotide template. The total yield of polymerization remains limited although 50% more pyrophosphate bonds are formed in the presence of polypeptide. However, the elongation effect is more significant since the yield of oligomers longer than the decamer is increased by a factor of 60. The possible prebiotic implications of these experiments are discussed.

Nicotinamide mononucleotide is conveniently prepared from nicotinamide adenine dinucleotide by specific hydrolysis of the pyrophosphate bond using the Zr4+ ion as catalyst.