Antimicrobial peptidomimetics

A compound of the formula (I):

• wherein
• L1 represents —CO—, alkandiyl, -alkyl-CO— or —CO-alkyl-;
• L2 represents —CO—, alkandiyl, -alkyl-CO— or —CO-alkyl-;
• L3 represents —CO—, alkandiyl, -alkyl-CO— or —CO-alkyl-;
• R1 represents hydrogen, acyl, carbamoyl, alkylaminocarbonyl, dialkylaminocarbonyl, arylcarbonyl, cycloalkylcarbonyl or heterocyclylcarbonyl;
• R2 represents optionally substituted alkyl, aralkyl or heteroaralkyl;
• R3 represents hydrogen, or represents optionally substituted alkyl, aralkyl or heteroaralkyl;
• R4 represents optionally substituted alkandiyl, alkendiyl, alkyndiyl, cycloalkyldiyl, alkylcycloalkyldiyl, alkylcycloalkylalkyldiyl, aryldiyl, alkylaryldiyl, alkylarylalkyldiyl;
• R5 represents hydrogen, or represents optionally substituted alkyl, aralkyl or heteroaralkyl;
• R6 represents hydrogen, or represents optionally substituted alkyl, aralkyl or heteroaralkyl;
• provided that at least two of the substituents R2, R3, R5 and R6 are optionally substituted aralkyl or heteroaralkyl;
• wherein at least one of R2 or R3 is an optionally substituted biphenyl-C1-C4-alkyl;
• n is 0, 1, 2, 3 or 4;
• and
• m is 0 or 1;
• Q is —NH2, —NH—C(NH)—NH2 or —NH—C(N-alkyl)-NH-alkyl;
• X is NH, O or S;
• Z1 is —CH2—;
• Z2 is a direct bond, alkandiyl, cycloalkyldiyl or aryldiyl;
• or a salt of such compound.