Semi-synthetic glycopeptides having antibacterial activity are described, in particular, the semi-synthetic glycopeptides described herein are made by chemical modification of the a glycopeptide (Compound A, Compound B, Compound H or Compound C) or the monosaccharide made by hydrolyzing the disaccharide moiety of the amino acid-4 of the parent glycopeptide in acidic medium to give the amino acid-4 monosaccharide; conversion of the monosaccharide to the amino-sugar derivative; acylation of the amino substituent on the amino acid-4 amino-substituted sugar moiety on these scaffolds with certain acyl groups; conversion of the amide group in amino acid-3 on these scaffolds to various acylamide, acylsulfonamide, acylsulfonylurea derivatives; aminomethylation with substituent containing sulfonamide or acylsulfonamide group on amino acid-7 through Mannich reaction; and conversion of the acid moiety on the macrocyclic ring of these scaffolds to certain substituted amides. Also provided are methods for the synthesis of the compounds, pharmaceutical compositions containing the compounds, and methods of use of the compounds for the treatment and/or prophylaxis of diseases, especially bacterial infections.