Peptide derivatives as antibiotics

1. A pharmaceutical composition comprising a compound of formula (I):

Xaa 1 -Xaa 2 -Xaa 3 -Xaa 4 -Xaa 5 -Xaa 6 -Xaa 7 -Xaa 8 -Xaa 9 -Xaa 10 -NH—(CH 2 ) n —R  (I)

wherein

Xaa 1 , Xaa 2 , Xaa 3 , Xaa 5 , Xaa 7 , Xaa 8 and Xaa 10 are independently selected from the group consisting of lysine, 3-hydroxylysine, 4-hydroxylysine, 5-hydroxylysine, 3,4-dihydroxylysine, 3,5-dihydroxylysine, 4,5-dihydroxylysine, ornithine, 3-hydroxyornithine, 4-hydroxyornithine, 3,4-dihydroxyornithine, 2,4-diaminobutanoic acid, 3-hydroxy-2,4-diaminobutanoic acid, arginine, histidine, serine, and threonine;

Xaa 4 is glycine, 3-aminopropanoic acid, or 4-aminobutanoic acid;

Xaa 6 is proline, 3-hydroxyproline, 4-hydroxyproline, aziridine-2-carboxylic acid, azetidine-2-carboxylic acid, pipecolic acid, 4-oxaproline, 3-thiaproline, 4-thiaproline, 3,4-dehydroproline, 4-aminoproline, 4-fluoroproline, α-methylproline, or α-allylproline;

Xaa 9 is arginine, 2,3-dehydroarginine, citrulline, 2,3-dehydrocitrulline, canavanine, or 2,3-dehydrocanavanine;

n is 2, 3, 4, 5, 6, 7, 8, 9, or 10;

R is —OH, —NH 2 , or —COOH, and

an aminoglycoside antibiotic.

2. The Pharmaceutical composition of claim 1 , wherein

Xaa 1 is lysine;

Xaa 2 and Xaa 3 are each 3-hydroxy-2,4-diaminobutanoic acid;

Xaa 4 is glycine;

Xaa 5 is ornithine;

Xaa 6 is proline;

Xaa 7 is histidine; and

Xaa 9 is 2,3-dehydroarginine.

3. The pharmaceutical composition of claim 1 , wherein

Xaa 1 is lysine;

Xaa 2 and Xaa 3 are each 3-hydroxy-2,4-diaminobutanoic acid;

Xaa 4 is glycine;

Xaa 5 is ornithine;

Xaa 6 is proline;

Xaa 7 is histidine;

Xaa 8 is lysine or 5-hydroxylysine;

Xaa 9 is 2,3-dehydroarginine; and

Xaa 10 is lysine or 5-hydroxylysine.

4. The pharmaceutical composition of claim 1 , wherein

Xaa 1 is lysine;

Xaa 2 and Xaa 3 are each 3-hydroxy-2,4-diaminobutanoic acid;

Xaa 4 is glycine;

Xaa 5 is ornithine;

Xaa 6 is proline;

Xaa 7 is histidine;

Xaa 8 is lysine or 5-hydroxylysine;

Xaa 9 is 2,3-dehydroarginine;

Xaa 10 is lysine or 5-hydroxylysine;

n is 4; and

R is NH 2 .

5. The pharmaceutical composition of claim 1 , wherein the compound is a compound of formula (Ia):

6. The pharmaceutical composition of claim 1 , wherein the compound is a compound of formula (Ib):

7. The pharmaceutical composition of claim 1 , wherein the compound is a compound of formula (Ic):

8. The pharmaceutical composition of claim 1 comprising a pharmaceutically acceptable carrier.

9. The pharmaceutical composition according to claim 1 wherein the aminoglycoside antibiotic compound is kanamycin or gentamicin.