Interaction of ribose nucleotides with zinc oxide and relevance in chemical evolution

Metal oxides are the important constituents of the crusts of earth-like planets. Therefore, it is probable that metal oxides present on earth or in the primeval seas must have catalyzed different reactions in the course of chemical evolution and origin of life. The present report deals with the interaction of ribose nucleotides namely, 5′-AMP, 5′-GMP, 5′-CMP and 5′-UMP with zinc oxide. Adsorption of nucleotides on zinc oxide followed Langmuir adsorption isotherm. Xm and KL values were calculated. Adsorption was found to be maximum in neutral medium as compared to acidic and basic medium. Infrared spectral studies of ribonucleotides, metal oxide and ribonucleotide–metal oxide adducts indicate that the nitrogen base and phosphate moiety of ribonucleotides interact with the positive charge surface of metal oxide. SEM studies were also done to support adsorption of nucleotides on zinc oxide. Results of the present study suggest the importance of metal oxides in concentrating the organic molecules from their dilute aqueous solutions in primeval seas.