[The structure of the aglycon of eremomycin--a new antibiotic of the polycyclic glycopeptide group]. / Struktura aglikona éremomitsina--novogo antibiotika gruppy politsiklicheskikh glikopeptidov.

Eremomycin is shown to be a new representative of the group of polycyclic glycopeptides. By the amino acid composition it is close to vancomycin but by the structure of triphenoxytriaminotricarboxylic acid it differs from vancomycin. Monodechlorovancomycinic acid was detected in eremomycin. On the basis of the data obtained in studies on the amino acid sequence and the molecule functional groups the structural formula of eremomycin aglycon was assigned. It is demonstrated that the chlorine-containing phenylserine fragment of monodechlorovancomycin acid is located in the N-end region of the aglycon peptide chain.

[Modification of eremomycin by amine groups]. / Modifikatsiia éremomitsina po aminnym gruppam.

Possible modification of eremomycin, a novel glycopeptide antibiotic by the amine groups with acylating agents such as Ac2O/MeOH and CH3(CH2)7COCl/Et3N and alkylating agents such as CH3CHO, NaBH and NaBH3CN was studied. N-Acetyl, N,N'-diacetyl. N-pelargoil, N-ethyl, N,N'-diethyl and N,N',N"-triethyl derivatives of eremomycin were prepared. Their structure was asserted and the order of the substitute introduction was determined. The antimicrobial activity against Bacillus subtilis and Staphylococcus aureus was assayed. It was found that with introduction of the ethyl substitutes to the eremomycin molecule the antibiotic activity lowered insignificantly whereas the acylation resulted in its decreasing by 1-2 orders.

[The structure of eremomycin, a new antibiotic of the group of polycyclic glycopeptides]. / Struktura éremomitsina--novogo antibiotika gruppy politsiklicheskikh glikopeptidov.

Structure of the carbohydrate moiety of the eremomycin molecule was assessed. Two residues of eremosamine were detected in the antibiotic. One of them in the composition of 2-0-(L-eremosaminyl)-D-glucopyrazone dissaccharide was linked by the phenol group to monodechlorvancomycinic acid and the other formed the monosaccharide branch by the alcohol group of the same acid at the peptide C-end area. On the basis of the results of the present study and the data published earlier (structure of the aglycone and aminosugar) the structure of eremomycin was assigned.