Synthesis and characterization of amphiphilic monodisperse compounds and poly(ethylene imine)s: influence of their microstructures on the antimicrobial properties.
Amphiphilic monodisperse compounds (series B-I and B-II) and poly(ethylene imine)s (PEI-I, PEI-II, and PEI-III) with different microstructures were prepared from primary amines or poly(ethylene imine) with functional carbonates bearing cationic, hydrophobic, or amphiphilic groups. Their inhibition potential against proliferation of  E. coli ,  S. aureus , and  B. subtilis  was investigated and their hemolytic activities were determined. The influence of the microstructures, the alkyl chain length and the distribution of cationic and hydrophobic groups, on their antimicrobial efficacy was studied. Amphiphilic compounds with long alkyl chains (C14-C18) directly linked to the cationic groups (series B-I) are more effective against both Gram-positive and Gram-negative bacteria than amphiphilic compounds in which the hydrophobic and cationic groups (series B-II) are connected by a spacer. Poly(ethylene imine)s with amphiphilic grafts (B-I) called PEI-II are more effective than amphiphilic PEIs with the same alkyl chain but with randomly linked cationic and hydrophobic graft called PEI-I or with the amphiphilic grafts (B-II) called PEI-III. The influence of the inoculum size on the MIC value was investigated exemplarily with compounds of series B-I against  S. aureus .
Institute of Technical and Macromolecular Chemistry and DWI an der RWTH Aachen e.V., RWTH Aachen , Forckenbeckstrasse 50, D-52056, Aachen, Germany.
Yingchun
Y
He
Elisabeth
E
Heine
Nina
N
Keusgen
Helmut
H
Keul
Martin
M
Möller
D000900:Anti-Bacterial Agents / Q000138:chemical synthesis* / Q000494:pharmacology*; D002478:Cells, Cultured; D004912:Erythrocytes / Q000187:drug effects; D005453:Fluorescence; D006090:Gram-Negative Bacteria / Q000187:drug effects*; D006094:Gram-Positive Bacteria / Q000187:drug effects*; D006461:Hemolysis / Q000187:drug effects; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D007097:Imines / Q000737:chemistry*; D008826:Microbial Sensitivity Tests; D055616:Microtechnology; D015394:Molecular Structure; D011095:Polyethylenes / Q000737:chemistry*; D000644:Quaternary Ammonium Compounds / Q000737:chemistry*
D000900:Anti-Bacterial Agents; D007097:Imines; D011095:Polyethylenes; D000644:Quaternary Ammonium Compounds; C505405:poly(ethylene imine)