Glutathione transferase activity with a novel substrate mimics the activation of the prodrug azathioprine.

Azathioprine is a prodrug that is widely used clinically as an immunosuppressive agent. The pharmacological action of azathioprine is associated with the release of 6-mercaptopurine by a reaction involving glutathione. This biotransformation of azathioprine is catalyzed by glutathione transferases (GSTs).

New crystal structures of human glutathione transferase A1-1 shed light on glutathione binding and the conformation of the C-terminal helix.

Human glutathione transferase A1-1 is a well studied enzyme, but despite a wealth of structural and biochemical data a number of aspects of its catalytic function are still poorly understood. Here, five new crystal structures of this enzyme are described that provide several insights. Firstly, the structure of a complex of the wild-type human enzyme with glutathione was determined for the first time at 2.

Acidity of di- and triprotected hydrazine derivatives in dimethyl sulfoxide and aspects of their alkylation.

The pK(a) values in DMSO for 22 di- and triprotected hydrazine NH acids and two monosubstituted hydrazines have been determined using potentiometric titration. The results of density functional theory calculations at the B3LYP/6-311+G level of gas-phase acidities of a representative selection of mono-, di-, and trisubstituted hydrazines are compared with both the relevant published and novel experimental titration data. In the course of this work, a rough estimation of the pK(a) value of hydrazine in DMSO (ca.

Reagent for synthesis of secondary amines by two consecutive N-alkylations and its application to orthogonally protected spermidine.

A novel reagent, tert-butyl 2-naphthalenesulfonylcarbamate, has been designed to allow the stepwise synthesis of secondary aliphatic amines by two consecutive N-alkylations with intermediate Boc-cleavage and final desulfonylation under mild and experimentally convenient conditions. Its application was demonstrated to make an orthogonally protected spermidine derivative, suitable for further selective modification. Each individual step, including the final cleavage of 2-naphthalenesulfonyl to provide the secondary amine nitrogen, took place in high yield.