The Effect of Halogen-to-Hydrogen Bond Substitution on Human Aldose Reductase Inhibition.

The effect of halogen-to-hydrogen bond substitution on the binding energetics and biological activity of a human aldose reductase inhibitor has been studied using X-ray crystallography, IC50 measurements, advanced binding free energy calculations, and simulations. The replacement of Br or I atoms by an amine (NH2) group has not induced changes in the original geometry of the complex, which made it possible to study the isolated features of selected noncovalent interactions in a biomolecular complex.

Cross-cyclotrimerization with two nitriles as a synthetic pathway to unsymmetrically 3,3'-disubstituted bis(tetrahydroisoquinolines).

Microwave assisted CpCo(CO)(2) catalyzed cross-cyclotrimerizations of 1,7,9,15-hexadecatetrayne with two different nitriles to give unsymmetrically substituted bis(tetrahydroisoquinolines) was studied. The reaction proceeded with a range of alkyl and aryl nitriles with reasonable isolated yields.