Biomolecular homochirality

Tranter, G. E. 1986. Parity-violating Energy Differences and the Origin of Biomolecular Homochirality. J. Theor. Biol. 119, 467-479. 

Such a capability of an oligonucleotide system deserves special attention in the context of the problem of the origin of biomolecular homochirality breaking molecular mirror symmetry by de-racemization is an intrinsic property of such a system whenever the constitutional complexity of the products of co-oligomerization exceeds a critical level. 

Bolli, M., Micura, R., and Eschenmoser, A. (1997a). Ryranosyl-RNA chiroselective self-assembly of base sequences by ligative oligomerization of tetranucleotide-2, 3 -cyclophosphates (with a commentary concerning the origin of biomolecular homochirality). Chem. Biol, 4, 309-20. 

Without a doubt, these effects deserve further experimental investigation and kinetic analysis. They are not only of interest for the origin of biomolecular homochirality but also as a possible innovation in enantio-selective synthesis, as well as a remarkable example of nonlinear behavior through auto catalytic reaction kinetics. 

Since the enantiomeric resolution of tartaric acid in 1848 by Pasteur, a longstanding issue is whether mirror-image molecules are energetically identical with respect to the origin of biomolecular homochirality [100]. In 1860 Pasteur first conjectured that the homochirality may come from certain intrinsically handed force existing in the Universe [1]. In 1898, Kipping and Pope reported experimental results in relation to NaC103 with l- and d-... 

One of the most exciting and recently emerging areas in asymmetric synthesis is asymmetric amplification. This topic has extraordinarily broad implications from mechanistic insights provided by non-linear effects to the enhancement of enantiomeric composition of important compounds to new hypotheses for the origin of biomolecular homochirality. The final chapter by Henri Kagan and David Fenwick provides a thorough and insightful analysis of the basic principles of asymmetric amplification and illustrations of some of the more important applications in synthesis. 

The fact that the ee of meteoritic w-alkyl amino acids has the same (l) orientation as that of biogenic material has raised considerable investigation for (i) understanding the origin of such ee and (ii) designing amplification processes to make the transition between quite modest ees (a few percent) and biomolecular homochirality. As non-racemizable compounds, non racemic a-alkyl amino acids may have played a seeding role in further amplification processes [72,73] (see Sect. 4.2). 

Podlech J (2001) Origin of organic molecules and biomolecular homochirality. Cell Mol Life Sci 58 44-60... 

Jorissen A, Cerf C (2002) Asymmetric photoreactions as the origin of biomolecular homochirality a critical review. Orig Life Evol Biosph 32 129-142... 

A characteristic hallmark of life is believed to be its homochirality .36 In general, it is true, although natural products are not always enantiomerically pure.37 The origin of biomolecular homochirality is discussed in depth by MacDermott.36 Those who are interested to see whether the parity-violating weak force is the cosmic dissymmetry that Pasteur was looking for should read her chapter in the book entitled Chirality in Natural and Applied Sciencd. 

Bailey J., Chrysostomou A., Hough J.H., Gledhill T.M., McCall A., Clark S., Menard F.,TamuraM. (1998) Circular polarization in star-formation regions implications for biomolecular homochirality. Science 281, 672—4. 

W. Bonner, Parity violation and the evolution of biomolecular homochirality, Chirality 12 (2000) 114-126. 

R. Berger, M. Quack, G. Tschumper, ElectroAveak quantum chemistry for possible precursor molecules in the evolution of biomolecular homochirality, Helv. Chim. Acta 83 (2000) 1919-1950. 

P. Schwerdtfeger, J. Laerdahl, R. Wesendrup, Biomolecular homochirality, in Proc. 37th lUPAC Congress, Vol. 1, GDCh, Berlin, 1999, p. 98. 

R. Janoschek, Theories on the origins of biomolecular homochirality, in R. Janoschek (Ed.), Chirality From weak bosons to the a-helix, Springer, Berlin, 1991, Ch. 2, pp. 18-33. 

Tranter G.E. (1985) Parity violation energy difference of chiral minerals and the origin of biomolecular homochirality. Nature 318, 1712-1713. McDermott A.J. (1996) The weak force and SETT the search for extra-terres-trial homochirality. Physical origin of homochirality in life, Amer. Inst. Phys. Conf, Santa Monica CA, Febr. 1995, Proceedings, Cline D.B. (ed.). Press Woodbury, N.Y., p. 241-254. 

It is worth noting, however, that nonlinear effects are actually observed in aldol and in other proline (or amino acid)-catalyzed reactions when proline is not completely solubilized in the reaction medium this phenomenon, which is due to the differential solubility of racemic and of enantiopure solid proline, was independently uncovered by Hayashi, Blackmond, and Breslow [21] and has been proposed as one of the possible mechanisms that led to biomolecular homochirality in prebiotic chemistry [22]. 

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