Enantioselective desymmetrization of meso bicyclic hydrazines: a novel approach to the asymmetric synthesis of polysubstituted amino cyclopentanic cores.

Catalytic asymmetric hydroboration can be successfully applied to meso bicyclic hydrazines. The resulting alcohols are of great synthetic interest and can lead in a straightforward manner to cyclopentanic diamino alcohols with good enantiomeric purity.

Design, synthesis, tandem mass spectrometric sequencing and biological activity of NGF mimetics.

Nine low molecular weight nerve growth factor (NGF)-like peptides have been designed to mimic the putative receptor-binding epitope of NGF defined by two beta-hairpin loops. Eight different spacers were used as variable links between the beta-loop amino acid residues, which from mutagenesis experiments were found to play an important role in the biological activity of NGF. These spacers were amino acids, natural or non-natural, differing in length (5-13 A) and polarity. The peptides were synthesized via the Fmoc solid-phase peptide synthesis and purified by reversed-phase HPLC. Their primary sequences were analyzed by a combination of automated Edman degradation and mass spectrometry. The peptides were tested using two different biological assays, the fibre outgrowth from chick embryonic sympathetic ganglia and the PC12 cell differentiation assay. Weak antagonistic effects could be observed for some peptides.