High temperature sublimation of α-amino acids: a realistic prebiotic process leading to large enantiomeric excess.
نویسندگان
چکیده
The reiterative high temperature co-sublimation of an enantiopure or an enantioenriched α-amino acid mixed with racemic α-amino acids leads to deracemization of the latter. A synergistic effect is observed for complex mixtures, and the sense of the handedness is, for all compounds, identical to that of the enantioenriched starting material.
منابع مشابه
Enantioenrichment in sublimed amino acid mixtures.
A real amplification of an initial enantiomeric excess can be detected when two amino acids are sublimed at high temperature, even if one of the components is a racemic compound that does not convert into a conglomerate by sublimation.
متن کاملA simple explanation of the enhancement or depletion of the enantiomeric excess in the partial sublimation of enantiomerically enriched amino acids.
In the partial sublimation of three enantiomerically enriched amino acids, the ee of the sublimates can be explained by the ratio between the saturated vapor pressures of the racemate and the pure enantiomers.
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There is overwhelming evidence that meteorites bring a-methylated amino acids to earth with some L(S) enantiomeric excess. How does that get transferred into normal biological molecules? In this brief account, we show that an a-methylated amino acid, D(R)-a-methylvaline, can react with pyruvate and phenylpyruvate salts in dry mixtures to form alanine and phenylalanine with L enantiomeric excess...
متن کاملRacemization of Meteoritic Amino Acids
Meteorites may have contributed amino acids to the prebiotic Earth, affecting the global ratio of right-handed to left-handed (D/ L) molecules. We calculate D/ L ratios for seven biological, α-hydrogen, protein amino acids over a variety of plausible parent body thermal histories, based on meteorite evidence and asteroid modeling. We show that amino acids in meteorites do not necessarily underg...
متن کاملAmplification of enantiomeric concentrations under credible prebiotic conditions.
Solutions with as little as 1% enantiomeric excess (ee) of D- or L-phenylalanine are amplified to 90% ee (a 95/5 ratio) by two successive evaporations to precipitate the racemate. Such a process on the prebiotic earth could lead to a mechanism by which meteoritic chiral alpha-alkyl amino acids could form solutions with high ee values that were needed for the beginning of biology.
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عنوان ژورنال:
- Chemical communications
دوره 51 32 شماره
صفحات -
تاریخ انتشار 2015