Indications towards a stereoselectivity of the salt-induced peptide formation reaction

Abstract

Different reaction yields for l- and d-alanine in the salt-induced peptide formation (SIPF) reaction, differences in the circular dichroism spectra and the complex formation constants of the involved chlorocuprate complexes point at a stereoselective differentiation between the two stereoisomers in the SIPF reaction and give a possible explanation towards the origin of homochirality in the process of the origin of life. An explanation of the observed effects can for the time being only be based on assumptions but could possibly be related to the inherent chirality of the Cu II ion as a central atom of the [CuCl(gly)(glyH 2)(H 2O) 2] + complex due to parity violation in weak interactions and to amplification of chirality related to the structural properties of the complex.