Acylated nonadepsipeptides containing pyridyl alanine residues

1. A compound of the formula

in which

R 1 is hydrogen, and

R 2 is 2-ethyl-2-methylbut-1-yl, 2,2-diethylbut-1-yl, 2,2-dimethylpent- l-yl or trimethylsilylmethyl,

or

R 1 is trifluoromethyl, and

R 2 is 2,2-dimethyiprop- l-yl, 2,2-dimethylbut- l-yl, 2-ethyl-2-methylbut- l-yl, 2,2-diethylbut- l-yl, 2,2-dimethylpent- l-yl or trimethylsilylmethyl,

or one of its salts.

2. The compound according to claim 1 , wherein

R 1 is hydrogen, and

R 2 is trimethylsilylmethyl,

or

R 1 is trifluoromethyl, and

R 2 is 2,2-dimethylprop-1 -yl, 2,2-dimethylbut-1 -yl or trimethylsilylmethyl.

3. The compound according to claim 1 , wherein

R 1 is hydrogen, and

R 2 is 2-ethyl-2-methylbut-1 -yl, 2,2-diethylbut-1 -yl or trimethylsilylmethyl.

4. The compound according to claim 1 having the following structure 3-(trimethylsilyl)- D -alanyl-3-(pyridin-3 -yl)- L -alanyl-de( 1 - D -leucyl-2- L -leucyl)lysobactin

or one of its salts.

5. A process for preparing a compound of the formula (I) according to claim 1 , comprising reacting the compound of the formula

with a compound of the formula

in which R 1 and R 2 have the meaning indicated in claim 1 , and X 1 is halogen or hydroxy.

6. A medicament comprising a compound according to any of claims 1 to 4 in combination with an inert, non-toxic, pharmaceutically suitable excipient.

7. The medicament according to claim 6 for the treatment of bacterial infections.

8. A method for controlling bacterial infections in humans and animals in need thereof by administration of an antibacterially effective amount of at least one compound according to any of claims 1 to 4 .

9. A method for controlling bacterial infections in humans and animals in need thereof by administration of an antibacterially effective amount of a medicament according to claim 6 .