A new class of 1,3,5-triazinyloxyimino derivatives were prepared, characterized and tested for reactivity in solution peptide synthesis. The new triazinyloxyimino derivatives failed to activate the carboxyl group during formation of peptide bonds, but gave the corresponding N-triazinyl amino acid derivatives as a major product. The oxyma (ethyl 2-cyano-2-(hydroxyimino)acetate) uronium salt was ...

A novel migratory dynamic kinetic resolution based on the interplay between an enzyme acylation catalyst and a heterogeneous Brønsted acid as an isomerization/racemization catalyst gives rise to carbocyclic allylic esters with excellent stereoselectivity from readily available tertiary carbinols. An easy-to-use teabag setup combining resin-bound catalysts, a biphasic isooctane-water solvent sys...

Bullvalene is a structurally unique dynamic molecule thought to interconvert among 1.2 million degenerate isomers. The incorporation of different chemical substituents onto the bullvalene core should lead to a "shape-shifting" molecule that can interconvert among thousands of discrete structural isomers. Previous NMR spectroscopy and HPLC studies on substituted bullvalenes ascertained the fact ...

In forensic medicine, the personal identification of cadavers is one of the most important tasks. One method of estimating age at death relies on the high correlation between racemization rates in teeth and actual age, and this method has been applied successfully in forensic odontology for several years. In this study, we attempt to facilitate the analysis of racemized amino acids and examine ...

Stereochemical studies on tyrosine phenol-lyase from Escherichia intermedia have shown that the alpha, beta-elimination reactions of L-serine and D- and L-tyrosine proceed with retention of configuration at C-beta. Stereospecifically beta-tritiated L-serine is slowly racemized at C-beta. Deuterium from the alpha-position of L-tyrosine is partially transferred to C-4 of the phenol formed when th...

Peptide synthesis has been developed into one of the most efficient synthetic procedures in organic chemistry. The problems of orthogonal functional group protection and amide bond formation without racemization have been developed in a number of ingenious strategies. Optimization, in particular, has been achieved in stepwise solid phase synthesis. This in turn made possible the development of ...

In a previous paper (1) evidence was presented that acid hydrolysates of the cellular material of BaciZZus brevis (ATCC 10068) contained an unusually high content of amino acids of the D configuration, amounting to over 10 per cent of the total amino acids or 5 per cent of the dry weight of the cells. The n-amino acids were shown to exist in the intact cells, and not to result from racemization...