Journal of Astrobiology & Outreach

Abstract

Role of Double Metal Cyanides in Chemical Evolution: Interaction of Ribose Nucelotides with Metal Hexacyanocobaltate(III)

Rachana S, Anand Kumar, Asif Iqubal Md and Kamaluddin

Based on the hypothesis on the presence of double metal cyanides in the primeval seas and their role as prebiotic catalyst, adsorption of RNA components, 5΄-GMP, 5΄-AMP, 5΄-CMP and 5΄-UMP on metal(II) hexacyanocobaltate(III) (MHCCo; M=Mn, Fe, Ni, Zn) has been investigated. The adsorption data obtained at neutral pH were found to follow Langmuir adsorption in the concentration range 1.0 × 10^-4 M to 3.0 × 10^-4 M. The value of Langmuir constants, Xm and KL were calculated from the slope and intercept of the respective isotherms. On the basis of infrared (IR) spectral studies of ribonucleotides, MHHCo, and ribonucleotides-MHCCo adducts, we propose that the nitrogen base, carbonyl and phosphate moiety of ribose nucleotides interact with the outer divalent metal ion of the MHCCo. A higher affinity as well as larger amount of adsorption of all the four ribonucleotides was found on the surface of FeHCCo, having a surface area of 238.67 m²/g. Based on our finding, it is proposed that surface area of MHCCos plays an important role in ribonucleotides adsorption by MHCCos. Among nucleotides studied adsorption affinity of 5΄-AMP was found maximum.