A Radical Pathway for Organic Phosphorylation during Schreibersite Corrosion with Implications for the Origin of Life

Phosphorylated compounds (e.g., DNA, RNA, phospholipids, and many coenzymes) are critical to biochemistry. Thus, their origin is of prime interest to origin of life studies. The corrosion of the meteoritic mineral schreibersite ((Fe, Ni)3P) may have significantly contributed to the origin of phosphorylated biomolecules. Corrosion of synthetic schreibersite in a variety of solutions was analyzed by nuclear magnetic resonance spectroscopy, mass spectrometry, and electron paramagnetic resonance spectroscopy. These methods suggest a free-radical reaction pathway for the corrosion of schreibersite to form phosphite radicals (PO32-) in aqueous solution. These radicals can form activated polyphosphates and can phosphorylate organic compounds such as acetate to form phosphonates and organophosphates (3% total yield). Phosphonates (O3P–C) are found in the organic P inventory of the carbonaceous meteorite Murchison. While phosphonates are rare in biochemistry, the ubiquity of corroding iron meteorites on the early Earth could have provided a source of organic phosphorous compounds for the origin of life, and may have led to the role of organophosphates as a product of early evolution