Is Boron a Prebiotic Element? A Mini-review of the Essentiality of Boron for the Appearance of Life on Earth

Abstract

Boron is probably a prebiotic element with special importance in the so-called "sugars world". Boron is not present on Earth in its elemental form. It is found only in compounds, e.g., borax, boric acid, kernite, ulexite, colemanite and other borates. Volcanic spring waters sometimes contain boron-based acids (e.g., boric, metaboric, tetraboric and pyroboric acid). Borates influence the formation of ribofuranose from formaldehyde that feeds the "prebiotic metabolic cycle". The importance of boron in the living world is strongly related to its implications in the prebiotic origins of genetic material; consequently, we believe that throughout the evolution of life, the primary role of boron has been to provide thermal and chemical stability in hostile environments. The complexation of boric acid and borates with organic cis-diols remains the most probable chemical mechanism for the role of this element in the evolution of the living world. Because borates can stabilize ribose and form borate ester nucleotides, boron may have provided an essential contribution to the "pre-RNA world".

Current data regarding the structure-toxicity relationship of boron-containing compounds

“…Despite the aforementioned century-long use of BCCs in the biomedical field, and the possible importance of these compounds for the beginning of primordial life as we know it (Scorei, 2012;Neveu, 2013;Stephenson, 2013;Silva, 2014), only scarce data exists about the biological effects induced by these compounds. With the exception of the last 15 years, the advances in the last century were limited to establishing the importance of boron (especially boric acid) in the nutrition of all types of living organisms (Nielsen, 1991;Hunt, 1996;Nielsen, 2014), or to reporting its toxicological effects.…”

Abiotic Regioselective Phosphorylation of Adenosine with Borate in Formamide

“…For example, the stabilization of ribose and other 5-carbon sugars by borate minerals reduces the formation of asphalts, making these species plausibly better precursors for RNA prebiotic synthesis (Ricardo et al, 2004;Kim et al, 2011;Furukawa et al, 2013). Other work related to borate and prebiotic chemistry has been done (Prieur, 2001a(Prieur, , 2001bSpringsteen and Joyce, 2004;Kofoed et al, 2005;Scorei and Cimpoiasu, 2006;Amaral et al, 2008;Rauchfuss, 2008;Cossetti et al, 2010;Grew et al, 2011;Scorei, 2012;Stephenson et al, 2013).…”

Prebiotic Phosphorylation Reactions on the Early Earth

“…Another example in which Mg 2+ ion catalyzes phosphorylation is the successful conversion of glycolaldehyde to glycolaldehyde phosphate (GAP) by using amidotri phosphate [53]. Furthermore, the role of borates in the stability of sugars is worth mentioning which not only stabilizes the sugars but also catalyzes the formation of sugar phosphates (such as ribose phosphate) by forming stable complexes to give better yields of [68,69].…”