The amino acid condensation reaction on a heterogeneous mineral surface has been regarded as one of the important pathways for peptide bond formation. Keeping this in view, we have studied the oligomerization of the simple amino acids, glycine and alanine, on nickel ferrite (NiFe2O4), cobalt ferrite (CoFe2O4), copper ferrite (CuFe2O4), zinc ferrite (ZnFe2O4), and manganese ferrite (MnFe2O4) nanoparticles surfaces, in the temperature range from 50–120 °C for 1–35 days, without applying any wetting/drying cycles. Among the metal ferrites tested for their catalytic activity, NiFe2O4 produced the highest yield of products by oligomerizing glycine to the trimer level and alanine to the dimer level, whereas MnFe2O4 was the least efficient catalyst, producing the lowest yield of products, as well as shorter oligomers of amino acids under the same set of experimental conditions. It produced primarily diketopiperazine (Ala) with a trace amount of alanine dimer from alanine condensation, while glycine was oligomerized to the dimer level. The trend in product formation is in accordance with the surface area of the minerals used. A temperature as low as 50 °C can even favor peptide bond formation in the present study, which is important in the sense that the condensation process is highly feasible without any sort of localized heat that may originate from volcanoes or hydrothermal vents. However, at a high temperature of 120 °C, anhydrides of glycine and alanine formation are favored, while the optimum temperature for the highest yield of product formation was found to be 90 °C.

Interaction of ribonucleotides with zinc ferrite nanoparticles (~15 nm) prepared by the solegel method was studied at physiological pH (~7.0). Ultra-violet (UVeVis), Fourier transform infrared (FT-IR), Raman spectroscopy and field emission scanning electron microscopy (FE-SEM) and atomic force microscopy (AFM) were employed to investigate the interaction of ribonucleotides with zinc ferrite surface. Langmuir and Freundlich adsorption models were used to describe the equilibrium isotherms in the concentration range of 1.0 Â 10 À4 MÀ4.0 Â 10 À4 M of ribonucleotides. The maximum adsorption capacity determined for 5 0 -GMP, 5 0 -AMP, 5 0 -UMP, 5 0 -CMP was 22.37 mg/g, 17.42 mg/g, 16.03 mg/g and 14.03 mg/g, respectively. Langmuir model was found to show the best fit for experimental data. Adsorption kinetics were studied by pseudo-first order and pseudo-second order kinetic models, and the adsorption process was best described by the pseudo-second order kinetic model. FE-SEM images clearly showed that ribonucleotide adheres onto the zinc ferrite nanoparticles surface. AFM analysis demonstrated that the root mean square roughness (Rms, S q ) and average roughness (S a ) increased from 0.98 nm to 1.80 and 0.67 nme1.38 nm, respectively following exposure to ribonucleotide. FT-IR spectroscopy revealed that the zinc ferrite nanoparticles interact strongly with the phosphate, carbonyl and amino groups of ribonucleotides. Raman spectra of 5 0 -AMP-zinc ferrite adduct showed the participation of amino and a phosphate group with zinc ferrite nanoparticles surface.

We propose that double metal cyanides that formed in primeval seas might have played a vital role in chemical evolution and the origin of life. An array of metal octacyanomolybdates (MOCMos) has been synthesized, and their role as catalyst in the formation of nucleobases from formamide has been studied. Formamide, a hydrolysis product of HCN, was taken as starting material for the formation of nucleobases. Recent studies support the presence of formamide on some celestial bodies. Metal octacyanomolybdates, MOCMos (M = Mn, Fe, Co, Ni, Cu, Zn, Cd), are found to be highly efficient catalysts in the conversion of formamide into different nucleobases. Neat formamide is converted to purine, 4(3H)-pyrimidinone, cytosine, adenine, 9-(hydroxyacetyl)-purine, and thymine in good yield when using MOCMos. The products formed were characterized by high-performance liquid chromatography and electrospray ionization mass spectrometry techniques. The results of our study show that insoluble double metal cyanides might have acted as efficient catalysts in the synthesis of various biologically important compounds (e.g., purines, pyrimidines) under primeval seas on Earth or elsewhere in our solar system.

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A prebiotic chemistry experiment involving interaction between ribonucleotides and spinel ferrite nanoparticles has been carried out.