Effects of borate on the ribose accumulation by formose-type reaction

Abstract

Ribose is a sugar of the essential building blocks of RNA and is an essential molecule for life. It is known that ribose can be formed by the formose reaction, a formaldehyde condensation reaction, but its low stability and selectivity have been considered a problem for ribose accumulation. It was also reported that while borate stabilizes ribose, it may inhibit ribose formation. Therefore, this study investigates the effects of borate on ribose formation by formose-type reactions in order to quantify how these opposing effects affect ribose accumulation in the early earth. Results showed that the maximum concentration of ribose decreased with higher borate concentrations, but the decreasing rate of ribose with borate is lower than that without borate. In addition, borate has the effect of increasing the relative abundance of ribose among the linear aldopentoses. These results suggest that borate is effective in the accumulation of ribose when considering the long geologic time on the early Earth.