Broad spectrum antibiotic compounds and use thereof
View Patent ↗The discovery of a non-ribosomal peptide synthetase (NRPS) gene cluster in the genome of Clostridium thermocellum that produces a secondary metabolite that is assembled outside of the host membrane is described. Also described is the identification of homologous NRPS gene clusters from several additional microorganisms. The secondary metabolites produced by the NRPS gene clusters exhibit broad spectrum antibiotic activity. Thus, antibiotic compounds produced by the NRPS gene clusters, and analogs thereof, their use for inhibiting bacterial growth, and methods of making the antibiotic compounds are described.
1. A compound according to Formula I:
where Y is C 1 -C 10 alkyl, and Z is hydrogen or a monosaccharide.
2. The compound of claim 1 where Y is a branched C 4 alkyl.
3. The compound of claim 2 where Y is —CH(CH 3 )CH 2 CH 3 .
4. The compound of claim 1 where Z is a hexose.
5. The compound of claim 4 where Z is xylose.
6. The compound of claim 1 having the stereochemistry of Formula II:
7. The compound of claim 1 having the structure:
8. A method of inhibiting bacterial growth, comprising contacting bacteria with the compound of claim 1 .
9. The method of claim 8 , wherein the bacteria are Gram-positive bacteria.
10. The method of claim 9 , wherein the Gram-positive bacteria are selected from the group consisting of Staphylococcus aureus, Streptococcus pneumoniae, Bacillus subtilis and Clostridium difficile.
11. The method of claim 8 , wherein the bacteria are Gram-negative bacteria.
12. The method of claim 11 , wherein the Gram-negative bacteria are selected from the group consisting of Pseudomonas aeruginosa, Salmonella enterica, Pseudomonas putida, Escherichia coli, Acinetobacter baumannii and Haemophilus influenzae.
13. The method of claim 8 , wherein the bacteria is a species of Mycobacterium.
14. The method of claim 13 , wherein the Mycobacterium species is Mycobacterium bovis or Mycobacterium tuberculosis.
15. The method of claim 8 , wherein the method is an in vitro method.
16. The method of claim 8 , wherein the method is an in vivo method and contacting bacteria with the compound comprises administering a therapeutically effective amount of the compound to a subject infected with the bacteria.
17. The method of claim 16 , wherein the subject is a non-human animal.
18. The method of claim 16 , wherein the subject is a human.
19. A method of making a compound according to Formula I:
where Y is C 1 -C 10 alkyl, and Z is hydrogen or a monosaccharide, the method comprising:
providing a first amino acid according to the formula Y—CH(NHnOS)C(O)OH, where nOS is a protecting group;
providing a homoserine analog according to the formula R″OCH 2 CH 2 CH(NH 2 )C(O)OH where R″ is a protecting group;
coupling the first amino acid to the homoserine analog to form an amino acid dimer;
providing a carbohydrate precursor having the structure
where R and R′ are protecting groups, and Z′ is hydrogen, R′″ where R′″ is a protecting group, or a monosaccharide precursor comprising one or more protecting groups in place of hydroxyl groups;
coupling the amino acid dimer to the carbohydrate precursor, thereby forming the structure
cyclizing the amino acid dimer and carbohydrate precursor, thereby forming the structure
removing protecting groups to form hydroxyl groups, wherein the protecting groups comprise R, R″ and, when Z′ is R′″, R′″; and
oxidizing the hydroxyl group formed by removal of R″, thereby forming the compound according to Formula I.
20. The method of claim 19 , wherein the first amino acid and the homoserine analog are coupled via an intermolecular condensation reaction using 1-mesitylene-2-fulsonyl-3-nitro-1,2,4-triazole.
21. The method of claim 19 , wherein the amino acid dimer is coupled to the carbohydrate precursor via pentafluorophenyl ester coupling.
22. The method of claim 19 , wherein the amino acid dimer and carbohydrate precursor are cyclized via a Mitsunobu reaction.
23. The method of claim 19 , wherein R is p-methoxybenzyl ether, R′ is n-pentenyl, and R″ is tert-butyldimethylsilyl ether.
24. The method of claim 19 , wherein Z is xylose and providing the carbohydrate precursor further comprises:
providing first and second monosaccharide precursors having the structures
where R, R′, and Bz are protecting groups p-methoxybenzyl ether, n-pentenyl, and benzoyl, respectively, and Ph is phenyl; and
coupling the first and second monosaccharide precursors to form the carbohydrate precursor, wherein the carbohydrate precursor has the structure
25. The method of 24 , wherein the first and second monosaccharide precursors are coupled via an intermolecular condensation reaction using trimethylsilyl trifluoromethanesulfonate.