Synthetic Resins Catalyzing the Racemization of Amino Acids. III. Racemization by the Column Procedure

Racemization 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...

Racemization of amino acids in marine sediments.

Isoleucine, one of several amino acids isolated from a suite of welldated deep-sea cores, shows a progressive increase in the degree of racemization with the age of the sediment. Amino acids in sediments show an initial rate of racemization almost an order of magnitude faster than the rate observed for free amino acids at a comparable pH and temperature. The observed kinetics depend on a variet...

Amino Acid Racemization

Correction: Abiotic Racemization Kinetics of Amino Acids in Marine Sediments

The ratios of d- versus l-amino acids can be used to infer the sources and composition of sedimentary organic matter. Such inferences, however, rely on knowing the rates at which amino acids in sedimentary organic matter racemize abiotically between the d- and the l-forms. Based on a heating experiment, we report kinetic parameters for racemization of aspartic acid, glutamic acid, serine, and a...

Simple procedure for preparing trifluoroacetylprolyl amino acids, acyl components in the racemization test for peptide synthesis by GLC.

Amongthe methods for racemization testing in peptide synthesis, the GLCmethod is a simple one and the most practicable, especially when a packed column is used. In this method Tfa-Pro-X-OH (X=amino acids) is coupled with H-Val-Pro-OMe, the resulting Tfa-tetrapeptide-OMe is separated by GLC, and the degree of recemization is estimated from the ratio of the peaks separated to the diastereoisomers...