Novel ammonium phosphinates containing peptide moiety: Synthesis, structure, and in vitro antimicrobial activity

Five new ammonium phosphinates with formula [XC₆H₄NHC(O)NHP(O)YO]^?[H₂Y]⁺ (Y = N(CH₃)(CH₂C₆H₅), X = H (IV), CH₃ (V), NO₂ (VI); Y = NH(CH₂C₆H₅), X = H (VII), NO₂ (VIII)) were synthesised by the reaction of N-arylureidophoshoryl dichlorides with N-methylbenzylamine or benzylamine in the presence of an excess amount of the corresponding amine. All new compounds were characterised by NMR and IR spectral data and elemental analysis. Their antimicrobial activity was tested against some Gram-positive and Gram-negative bacteria and fungi. Compounds IV and VIII exhibited moderate activity in vitro against Bacillus subtilis. In addition, compound VIII moderately inhibited Pseudomonas aeruginosa. The crystal structure of benzylmethylammonium(3-phenylureido)(benzylmethylamino)phosphinate (IV) was also determined. This compound crystallises in the orthorhombic system.