Racemization Catalyst for Amino Acid. IV Enantiomer Differentiating Racemization with (S)-2′-Nitro-5-nitroso-6,6′-dimethylbiphenyl-2-ol

Amino Acid Racemization

Amino acid racemization in Pseudomonas putida KT2440.

D-Amino acids have been shown to play an increasingly diverse role in bacterial physiology, yet much remains to be learned about their synthesis and catabolism. Here we used the model soil- and rhizosphere-dwelling organism Pseudomonas putida KT2440 to elaborate on the genomics and enzymology of d-amino acid metabolism. P. putida KT2440 catabolized the d-stereoisomers of lysine, phenylalanine, ...

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...

Photo Racemization and Polymerization of (R)-1,1'-Bi(2-naphthol).

(R)-1,1'-Bi(2-naphthol) ((R)-BINOL) in an acetonitrile solution lost optical activity upon irradiation with an Hg-Xe lamp. HPLC resolution of the product indicated that (R)-BINOL was racemized upon irradiation, and SEC analysis suggested that a polymeric product was formed in the course of racemization. It is proposed that polymerization of BINOL can occur before it is racemized and that a unit...