Chirality of the molecular assembly determined by intra-/inter-N–H⋯O hydrogen bonding in doubly substituted N-octanoylglyoxylic amides

Synthesis of Bis-Glyoxylamide Peptidomimetics Derived from Bis-N-acetylisatins Linked at C5 by a Methylene or Oxygen Bridge

The bis-glyoxylamide peptidomimetics have been synthesized from bis-N-acetylisatins linked at C5 by ring-opening with alcohols, amines, and amino acid methyl ester hydrochlorides. X-ray images of single crystals of bis-glyoxylamide peptidomimetics have been obtained.

Synthesis and biological evaluation of N-naphthoyl-phenylglyoxamide-based small molecular antimicrobial peptide mimics as novel antimicrobial agents and biofilm inhibitors

Antimicrobial peptides (AMPs) are a key component of the human immune system. Synthetic AMP mimics represent a novel strategy to counteract the increasing incidence of antimicrobial resistance. Here, we describe the synthesis of novel glyoxamide derivatives via ring-opening reactions of N-hexanoyl, N-benzoyl and N-naphthoylisatins with N,N-dimethylethane-1,2-diamine and N,N-dimethylpropane-1,3-diamine. These were converted to both the hydrochloric acid (HCl) or quaternary ammonium iodide (MeI) salts and their antibacterial activity against Staphylococcus aureus was investigated by their zone-of-inhibition and minimum inhibitory concentration (MIC). The HCl salt 22b exhibited the lowest MIC of 16 μg mL(-1), whereas the corresponding MeI salt 22c had a MIC of 39 μg mL(-1). We also investigated the in vitro toxicity of active compounds against the MRC-5 normal human lung fibroblasts and their activity against established biofilm in S. aureus.

Synthesis, Structures, and Conformations of Linked Bis-Glyoxylamides Derived from Bis-Acylisatins

A series of bis-glyoxylamides possessing hydrophobic alkyl chains was successfully synthesised by ring opening of bis-acylisatins with amines or amino acid alkyl esters. The crystal structures revealed the interplay of intra- and intermolecular interactions (NH···O and C=O···C=O interactions) and the conformations of these long molecules.