New semi-synthetic cyclic peptides as potential antifungal and antiprotozoal agents

Abstract

This patent deals with the synthesis, characterisation and biological activity of a large series of cyclic hexapeptides which display interesting activity against fungi (including Pneumocystis carinii) and protozoa. Novel semisynthetic methods are described and a broad spectrum antifungal activity is expected, as cyclic-hexapeptides are naturally occurring inhibitors of β-glucan synthesis. The antiprotozoal activity is surprising, since these organisms do not have cell walls, and suggests a novel mechanism of action. However, the information on antiprotozoal activity is scant and precludes the evaluation of the potential these new compounds have as antiparasitic drugs.

• antifungal
• antiprotozoal
• cyclic peptides