Alex J. Zhang

Total Syntheses of Vancomycin

A total synthesis of the vancomycin aglycon 1 has eluded synthetic chemists for so many years that the preparation of this molecule has become a vendetta for some groups. Finally, and almost simultaneously, research teams led by Evans and by Nicolaou have succeeded. Similarities and differences in their synthetic approaches are highlighted herein.

Dimeric β-turn peptidomimetics as ligands for the neurotrophin receptor TrkC

Abstract Twelve dimeric peptidomimetics 1 were prepared via a divergent–convergent strategy. These peptidomimetics incorporated the same amino acids as i+1 and i+2 residues in key β-turns of the neurotrophin NT-3. Cytosensor microphysiometry was used to gauge the effects of the dimers 1 on cells that overexpress the NT-3 receptor, TrkC. Increases in extracellular acidification rates were observed for some monomers 3, but the active dimers gave greater effects.

Design and synthesis of protein superfamily-targeted chemical libraries for lead identification and optimization.

This review chronicles original literature dating back to 1992 outlining the applications of parallel synthesis and combinatorial chemistry to the synthesis of compound libraries focused towards specific superfamilies of molecular targets. Target families that have received significant literature coverage include kinases, proteases, nuclear hormone receptors and cell surface receptors, notably GPCRs.

Pictet–Spengler synthesis of tetrahydro-β-carbolines using vinylsulfonylmethyl resin

Abstract A novel, solid phase Pictet–Spengler synthesis has been developed using vinylsulfonylmethyl resin. A library of 800 structurally diverse tetrahydro-β-carbolines was prepared in a four-step sequence starting from tryptamines. The final resin cleavage step enabled the introduction of a basic tertiary amine in the six-membered heterocyclic ring.

MALDI AND FAB MASS SPECTROMETRY OF NUCLEOSIDE TRIPHOSPHATES: A COMPARATIVE STUDY

Abstract Comparison of MALDI and FAB mass spectra of dATP, dTTP, dCTP, and dGTP shows that the former technique gives clear molecular ions with minimal fragmentation whereas the latter gives more fragment ions and weaker parent peaks.