A PLAUSIBLY PREBIOTIC SYNTHESIS OF PHOSPHONIC-ACIDS

THE insolubility of calcium phosphate in water is a significant stumbl ing block in the chemistry required for the origin of life(1). The dis covery of alkyl phosphonic acids in the Murchison meteorite(2) suggest s the possibility of delivery of these water-soluble, phosphorus-conta ining 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 genet ic systems, phosphonic acids may have been precursors to the first nuc leic acids(3). Here we report the synthesis of several phosphonic acid s, including the most abundant found in the Murchison meteorite, by ul traviolet irradiation of orthophosphorous acid in the presence of form aldehyde, primary alcohols, or acetone, We argue that similar reaction s might explain the presence of phosphonic acids in Murchison, and cou ld also have occurred on the prebiotic Earth.