Isovaline prebiotic

The variety of prebiotic organic reactions seems to be almost unlimited. Strasdeit et al. (2002) from the University of Hohenheim (Germany) reported the synthesis of zinc and calcium complexes of the amino acids valine and isovaline. They assume that these could have had a certain significance on the mineral-rich primeval Earth on heating to 593 K under nitrogen, valine was converted to the corresponding cyclic dipeptide. 

Likely products of step 2, precipitates of Zn or Ca salts of amino acids valine and isovaline, were subjected to heating to 320°C in a nitrogen atmosphere (Strasdeit et al. 2001), causing complete thermolysis. Besides the simple diketopiperazines (cyclic dipeptides) and other peptides, heterocyclic compounds arise, and ketones (namely, the symmetrical Ruzicka products which form from Ca salts after desamination of the amino acids, like 2,8-dimethylnonan-5-on) and other prebiotically feasible small molecules. As might be anticipated, product yields and distribution sensitively depend on whether Zn or Ca ions were involved. There is some quite simple precondition for... 

In 2004, Pizzarello and Weber studied a water-based prebiotic model of sugar syntheses from glycoaldehyde and formaldehyde in the presence of nonracemic alanine or isovaline. They demonstrated that the configuration of tetroses is affected by the chirality of the amino acid catalyst. 

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