학술논문

On the Stabilization of Ribose by Silicate Minerals.
Document Type
Article
Source
Astrobiology. Mar2011, Vol. 11 Issue 2, p115-121. 7p.
Subject
*RIBOSE
*SILICATES
*RNA
*QUANTUM chemistry
*STEREOISOMERS
*THERMODYNAMICS
*PREBIOTICS
Language
ISSN
1531-1074
Abstract
AbstractThe RNA-world theory hypothesizes that early Earth life was based on the RNA molecule. However, the notion that ribose, the sugar in RNA, is unstable still casts a serious doubt over this theory. Recently, it has been found that the silicate-mediated formose reaction facilitates the stabilization of ribose. Using accurate quantum chemical calculations, we determined the relative stability of the silicate complexes of arabinose, lyxose, ribose, and xylose with the intent to determine which would form predominantly from a formose-like reaction. Five stereoisomers were investigated for each complex. The stereoisomers of 2:1 ribose-silicate are the more stable ones, to the extent that the least stable of these is even more stable than the most stable stereoisomer of the other 2:1 sugar-silicate complexes. Thus, thermodynamically, a formose-like reaction in the presence of silicate minerals should preferentially form the silicate complex of ribose over the silicate complex of arabinose, lyxose, and xylose. Key Words: Prebiotic chemistry—Simulation—Silicate-organics interactions—Origin of life—RNA world. Astrobiology 11, 115–121. [ABSTRACT FROM AUTHOR]