8a596b57-6126-4f7a-ae0b-a9781039b23320210205091936557wseamdt@crossref.orgMDT DepositWSEAS TRANSACTIONS ON BIOLOGY AND BIOMEDICINE1109-951810.37394/23208http://wseas.org/wseas/cms.action?id=40112720202720201710.37394/23208.2020.17http://wseas.org/wseas/cms.action?id=23181A Computational Study of a Prebiotic Synthesis of the Steroid Progesterone (C and D Rings)NigelAylwardSchool of Chemistry and Molecular Biosciences, University of Queensland, Brisbane, Queensland, AUSTRALIAThe magnesium ion metalloporphyrin complex is shown to bind the ligands propyne (p) and ethyne (e) on the metal or nitrogen pyrrole sites as a two site catalyst in their copolymerization. The order of addition of the monomers is (pepee). The steroid ring D (pep) is formed first from the propyne adduct bound to the metal site and the but-diene adduct bound to the N-site. The optimal orientation of these adducts determines the β-orientation of the 17-substituent. Further reaction with hydroxyl radicals allows this to be a 17 β- acetyl substituent. Further addition of two ethyne monomers forms an N-diene cyclopentene derivative able to cyclise to form the steroid ring C (pee) with a trans conformation and a 13-β methyl substituent. The reactions have been shown to be feasible from the overall enthalpy changes in the ZKE approximation at the HF and MP2 /6-31G* level, and with acceptable activation energies.221202022120201826https://www.wseas.org/multimedia/journals/biology/2020/a065108-084.pdf10.37394/23208.2020.17.3http://www.wseas.org/multimedia/journals/biology/2020/a065108-084.pdfG.P.Moss, Nomenclature of steroids, Pure & Appl. Chem., 81,(10),1989, pp.1783-1822. W.R.Butt, Hormone Chemistry, D.van Nostrand Comp. Ltd., London, 1967. 10.1126/science.183.4125.610B.W. O’Malley and A.R. Means, Female steroid hormones and target cell nuclei, Science, 183, 1974, pp.610-620. A.L.Lehninger, Biochemistry,Worth, New York, 1975, pp. 298,296,687,683,680.S.Dev, Handbook of Terpenoids: Volume I: Triterpenoids,CRC Press, 2017, pp.581.10.1007/s11084-005-2044-xN.Aylward, and N.R.Bofinger, Possible origin for porphin derivatives in prebiotic chemistry - a computational study, Orig.Life Evol. Biosph. vol.35(4), 2005, pp.345-368. S.L.Miller and L.E.Orgel, The Origins of Life on Earth, Prentice-Hall Inc., Englewood Cliffs, N.J., 1975. Interstellar methylacetylene and Isocyanic Acid , Nature, 243, 1973, pp.45–410.1021/jp952787zK.Seki, M.He, R.Liu and H.Okabe, Photochemistry of cyanoacetylene at 193.3 nm. J.Phys.Chem.,100,1996, pp.5349-5353. 10.1016/b978-008044396-6/50004-6N.N.Aylward, a nd N.R.Bofinger, Carbon monoxide clusters in the formation of D-sugars and L-amino-acids in prebiotic molecular evolution on E arth, in G.Palyi, C.Zucchi, L.Cagliotti, (eds.), Progress in Biological Chirality, Elsevier, Oxford (GB), 2004, ch2, pp.429.N.N. Aylward, The synthesis of terpenes in prebiotic molecular evolution on Earth, in WSEAS New Aspects of Biomedical Electronics and Biomedical Informatics. Eds. C.A.Long, P.Anninos, T.Pham, G.Anastassopoulos, N.E.Mastorakis, 2008, pp.202-207. Gaussian03, Users Reference, Gaussian Inc., Carnegie Office Park, Bldg.6., Pittsburgh, PA 15106, USA, 2003. W.J.Hehre, L.Random, P.V.R. Schleyer, and J.A.Pople, Ab Initio Molecular Orbital Theory, Wiley, New York, 1986. 10.1002/qua.560200829J.A.Pople, H.B.Schlegel, R.Krishnan, D.J. DeFrees, J.S. Binkley, M.J. Frisch, R.A.Whiteside, R.J.Hout and W.J.Hehre, Molecular orbital studies of vibrational frequencies, Int.J.Quantum Chem. Symp. vol.S15, 1981, pp.269-278.J.P.Collman, L.S.Hegedus, J.R.Norton, R.G. Finke, Principles and Applications of Organotransition Metal Chemistry, University Science Books, Mill Valey, California, 1987.D.Mansuy,J.P.Battioni, D.Dupree,E.Santoni, J.Am.Chem.Soc.104, 1982, pp.6159-6161.N.N.Aylward, A prebiotic surface catalysed photochemically activated synthesis of α-lipoic acid, International Journal of Biochemistry Research, 2018, 3, pp.31-39.F.K.Fong, Light Reaction Path of Photosynthesis, Springer Verlag, 1982, pp.344.