Spontaneous Resolution and Super-coiling in Xerogels of the Products of Photo-Induced Formose Reaction

Orig Life Evol Biosph. 2019 Sep;49(3):187-196. doi: 10.1007/s11084-019-09583-8. Epub 2019 Oct 22.

Abstract

This work addresses the supramolecular self-organization in the xerogels of formose reaction products. The UV-induced formose reaction was held in over-saturated formaldehyde solutions at 70C without a catalyst. The solutions of the obtained carbohydrates were dried on a glass slide, and the obtained xerogels demonstrated a prominent optical activity, while the initial solutions were optically inactive. The xerogels contained highly elongated crystalline elements of a helical structure as well as the isometric ones. Thus xerogel formation was accompanied by a spontaneous resolution of enantiomers and separation of different-shaped supramolecular structures. The thick helices were twisted of thinner ones, while the latter were twisted of elementary structures having a diameter much smaller than 400 nm. Similar structural hierarchy is typical of biological macromolecules (DNA, proteins, and cellulose). Summarizing the obtained results, we proposed a hypothetical mechanism explaining the amplification of the initial enantiomeric excess, as well as chiral and chemical purification of the substances which were essential for the evolution of Life to start.

Keywords: Formose reaction; Self-assembly; Supercoiling.

MeSH terms

  • Carbohydrates / chemistry*
  • Formaldehyde / chemistry*
  • Gels
  • Origin of Life
  • Stereoisomerism

Substances

  • Carbohydrates
  • Gels
  • Formaldehyde
  • formose sugars