1. Field of the Invention
This invention relates to novel semi-synthetic glycopeptides having antibacterial activity, to pharmaceutical compositions comprising these compounds, and to a medical method of treatment.
2. Description of Related Art
The emergence of drug resistant bacterial strains has highlighted the need for synthesizing and identifying antibiotics with improved activity. Naturally occurring and semi-synthetic glycopeptide antibiotics used to combat bacteria infections include compounds such as eremomycin (structure A, X═H), A82846B (structure A, X═Cl), vancomycin, teicoplanin, and A-40,926, having the scaffolds A, B, C and D, below respectively:

These compounds are used to treat and prevent bacterial infection, but as with other antibacterial agents, bacterial strains having resistance or insufficient susceptibility to these compounds have been identified, and these compounds have been found to have limited effect against certain bacterial infections caused by glycopeptide resistant enterococci. Therefore, there is a continuing need to identify new derivative compounds which possess improved antibacterial activity, which have less potential for developing resistance, which possess improved effectiveness against bacterial infections that resist treatment with currently available antibiotics, or which possess unexpected selectivity against target microorganisms.