Abstract:
Peptides are important biomolecules which facilitate the understanding of complex
biological processes, which in turn could be serendipitous biological targets for future drugs. They are
classified as a unique therapeutic niche and will play an important role as fascinating agents in the
pharmaceutical landscape. Until now, more than 40 cyclic peptide drugs are currently in the market,
and approximately one new cyclopeptide drug enters the market annually on average. Interestingly,
the majority of clinically approved cyclic peptides are derived from natural sources, such as peptide
antibiotics and human peptide hormones. In this report, the importance of cyclic peptides is discussed,
and their role in drug discovery as interesting therapeutic biomolecules will be highlighted. Recently
isolated naturally occurring cyclic peptides from microorganisms, sponges, and other sources with a
wide range of pharmacological properties are reviewed herein.