A review. Natural products are a rich source of pharmacol. active mols. that have been used as such orthe irderivatives to improve their properties. Among pharmaceutical substances derived from natural sources, a predominant positionis occupied by antimicrobials, one of the most successful forms of life-saving drugs in the history of medicine. Medicinal chem. programs based on the glycopeptide corestructure have produced an ensemble of drugs that are potentanti-Gram-pos. agents differentiated not only by their spectrum of activity but also by mechanism of action, tissue distribution, and overall pharmacokinetic profiles.