The title compound, C6H2N3O7 -·C10H13Cl2N2 +, crystallizes with one 1-(2,3-di-chloro-phen-yl)piperazine (DP) cation and one picrate (PA) anion in the asymmetric unit. In the crystal structure, the DP cation and PA anion are inter-connected via several N-H⋯O and C-H⋯O hydrogen bonds. The DP cation and PA anion are further connected through C-Cl⋯π [3.8201 (4), 3.7785 (4) Å] and N-O⋯π [3.7814 (4) Å] inter-actions. The DP cations are further inter-connected via a weak inter-molecular Cl⋯Cl [3.2613 (4) Å] halogen-halogen inter-action. The combination of these supra-molecular inter-actions leads to a herringbone like supra-molecular architecture.
The spread of drug-resistant bacteria has imparted a sense of urgency in the search for new antibiotics. In an effort to develop a new generation of antibacterial agents, we have designed de novo charged lipopeptides inspired by natural antimicrobial peptides. These short lipopeptides are composed of cationic lysine and hydrophobic lipoamino acids that replicate the amphiphilic properties of natural antimicrobial peptides. The resultant lipopeptides were found to self-assemble into nanoparticles. Some were effective against a variety of Gram-positive bacteria, including strains resistant to methicillin, daptomycin and/or vancomycin. The lipopeptides were not toxic to human kidney and liver cell lines and were highly resistant to tryptic degradation. Transmission electron microscopy analysis of bacteria cells treated with lipopeptide showed membrane-damage and lysis with extrusion of cytosolic contents. With such properties in mind, these lipopeptides have the potential to be developed as new antibacterial agents against drug-resistant Gram-positive bacteria.