Structural characterization of biocidal oligoguanidines

Oligomeric quanidines can be obtained by polycondensation of guanidine hydrocholoride and 1,2-bis(2-aminoethoxy)ethane. A comparative MALDI-TOF mass spectrometry/NMR spectroscopy study with a C-13-labeled sample enabled the unambiguous analysis of a guanidine-based polymer. Among the four major product series unprecedented macrocyclic compounds were detected. The minimum inhibition concentrations for four different microorganisms were determined, showing excellent biocidal activities.