It is now widely speculated that life originated at the “Black Smokers” of the undersea hydrothermal vents, where conditions exist for the formation of the primary ingredients and their subsequent transformation to higher biotic species such as amino acids, alcohols, etc. Any possible routes for the prebiotic oligomerization of simple compounds like amino acids, necessary for cell formation, has so far not been well understood. However, Leman et al. recently reported that under standard laboratory conditions carbonyl sulfide (COS) can “mediate” the oligomerization of simple amino acids in moderate yield. COS being a well-known volcanic gas points to its possible role in prebiotic peptide formation in the environment of the hydrothermal vents. Based on a previously developed and tested model for selective (vibrational) energy transfer (SET), we show that a COS-catalyzed condensation of α-amino-acids can lead to the formation of polypeptides. We also indicate that other agents can act as catalysts of the amino acid condensation, such as Fe(CN)63− and cyanamide (H2N-CN). This is related to the existence of vibrations with a frequency near to that of the critical vibration of the reactant, ρw (NH2). This wagging vibration occurs at 1048 ± 10 cm−1 (the mean value of Cu and Ni complexes) and, as the vibration of the presumed catalyst lies at 2079 cm−1, one notes that one quantum of the catalyst equals two quanta of the NH2 wagging: 2079/2 × 1048 = 0.9919. This is a good indication of a resonance.
Having found that carbonyl sulfide (COS), works well as a catalyst in the transformation of amino acids to polypeptides, we have now tested COS as a catalyst also for the formation of substances that might be thought of as partners in the building of RNA. The model used was selective energy transfer (SET). This model implies that a certain number of vibrational quanta are donated from the catalyst system and a corresponding number of quanta of the reactant accept the energy thus transferred. In this way, we found that carbonyl sulfide, COS, was a perfect catalyst for combining, first, five molecules of formaldehyde to form one molecule of ribose, and next, five molecules of hydrogen cyanide, HCN, to form one molecule of adenine, one of the nucleobases of RNA. However, beyond this, we found that COS was a perfect catalyst for precisely all reactions, needed to build the RNA, ribonucleic acid.
This study is a continuation of our research on understanding the possible chemical routes to the evolution of life on earth based on the “Selective Energy Transfer” (SET) theory. This theory identifies the specific vibrational mode of the catalyst that is in energy-resonance with a suitable vibrational mode of the reactant. In this way, energy is transferred from catalyst to reactant up to the energy of activation, making possible a particular chemical outcome. Then, we extend this model to the mostly unknown and highly complex environment of the hydrothermal vents, to speculate how prebiotic chemicals, necessary for the evolution of life, could have formed. It is to the credit of the SET theory that it can reflect the slight difference in the catalytic system that gives dramatically very different chemical outcome. It is shown, here, how in model laboratory experiments, methanol gives dimethyl ether (DME) in a 100% yield with Cu exchanged montmorillonite as the catalyst, or a very different product methyl formate (MF) in lower yields, with another Cu2+ ion-exchanged clay mineral (laponite) as the catalyst system. We also show, based on standard laboratory experiments, how COS (carbonyl sulfide) with a strong absorption band at 2079 cm−1 by itself and/or catalyzed by montmorillonite with strong Si-O-Si asymmetric vibration of 1040 cm−1 can react with alpha-amino acids to form alpha-amino acid thiocarbamate (AATC), which we feel could represent the most primitive analogue to coenzyme A (CoASH), a highly versatile bio-enzyme that is vital both for the metabolism and the synthesis of biochemicals in the living system. AATC itself may have undergone evolutionary developments through billions of years to transform itself into coenzyme A (CoASH) and its acetyl ester analogue acetyl coenzyme A (ACoA).
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