Substantially pure glycopeptide antibiotics AC-98-1 ; AC-98-2; AC-98-3; AC-98-4 and AC-98-5

1. A substantially pure compound having the structure

or pharmaceutically acceptable salts thereof.

2. A substantially pure compound according to claim 1 having the structure

3. A method for treating bacterial infections in warm blooded animals which comprises providing to said animals an antibacterially effective amount of a compound according to claim 2 .

4. A pharmaceutical composition which comprises a compound according to claim 2 in association with a pharmaceutically acceptable carrier.

5. A method for preparing substantially pure glycopeptide antibiotic AC-98-1 comprising the steps of:

a. cultivating a suitable producing strain of Streptomyces hygroscopicus in a suitable culture medium under aerobic conditions to produce a mixture of AC-98 antibiotics containing AC-98-1;

b. recovering said mixture of AC-98 antibiotics containing AC-98-1; and

c. separating and isolating substantially pure AC-98-1 as the trifluoroacetic acid salt by reverse phase high pressure liquid chromatography with a mobile phase gradient of about 11% to about 25% acetonitrile in water containing about 0.02% trifluoroacetic acid.

6. The method according to claim 5 where the mobile phase is a gradient of about 40% to about 60% methanol in water containing about 0.02% trifluoroacetic acid.

7. A method for preparing substantially pure glycopeptide antibiotic AC-98-2 comprising the steps of:

a. cultivating a suitable producing strain of Streptomyces hygroscopicus in a suitable culture medium under aerobic conditions to produce a mixture of AC-98 antibiotics containing AC-98-2;

b. recovering said mixture of AC-98 antibiotics containing AC-98-2; and

c. separating and isolating substantially pure AC-98-2 as the trifluoroacetic acid salt by reverse phase high pressure liquid chromatography with a mobile phase gradient of about 11% to about 25% acetonitrile in water containing about 0.02% trifluoroacetic acid.

8. The method according to claim 7 where the mobile phase is a gradient of about 40% to about 60% methanol in water containing about 0.02% trifluoroacetic acid.

9. A method for preparing substantially pure glycopeptide antibiotic AC-98-3 comprising the steps of:

a. cultivating a suitable producing strain of Streptomyces hygroscopicus in a suitable culture medium under aerobic conditions to produce a mixture of AC-98 antibiotics containing AC-98-3;

b. recovering said mixture of AC-98 antibiotics containing AC-98-3; and

c. separating and isolating substantially pure AC-98-3 as the trifluoroacetic acid salt by reverse phase high pressure liquid chromatography with a mobile phase gradient of about 11% to about 25% acetonitrile in water containing about 0.02% trifluoroacetic acid.

10. The method according to claim 9 where the mobile phase is a gradient of about 40% to about 60% methanol in water containing about 0.02% trifluoroacetic acid.

11. A method for preparing substantially pure glycopeptide antibiotic AC-98-4 comprising the steps of:

a. cultivating a suitable producing strain of Streptomyces hygroscopicus in a suitable culture medium under aerobic conditions to produce a mixture of AC-98 antibiotics containing AC-98-4;

b. recovering said mixture of AC-98 antibiotics containing AC-98-4; and

c. separating and isolating substantially pure AC-98-4 as the trifluoroacetic acid salt by reverse phase high pressure liquid chromatography with a mobile phase gradient of about 11% to about 25% acetonitrile in water containing about 0.02% trifluoroacetic acid.

12. The method according to claim 11 where the mobile phase is a gradient of about 40% to about 60% methanol in water containing about 0.02% trifluoroacetic acid.

13. A method for preparing substantially pure glycopeptide antibiotic AC-98-5 comprising the steps of:

a. cultivating a suitable producing strain of Streptomyces hygroscopicus in a suitable culture medium under aerobic conditions to produce a mixture of AC-98 antibiotics containing AC-98-5;

b. recovering said mixture of AC-98 antibiotics containing AC-98-5; and

c. separating and isolating substantially pure AC-98-5 as the trifluoroacetic acid salt by reverse phase high pressure liquid chromatography with a mobile phase gradient of about 11% to about 25% acetonitrile in water containing about 0.02% trifluoroacetic acid.

14. The method according to claim 13 where the mobile phase is a gradient of about 40% to about 60% methanol in water containing about 0.02% trifluoroacetic acid.