Natural bioactive cyclopeptides from microbes as promising anticancer drug leads: A mini-review

Abstract

Natural products from microbes are a rich source of bioactive molecules to serve as drug leads, predominantly in cancer therapy. Peptides are among the essential nature-derived biomolecules. Owing to their great diversity and favorable characteristics, cyclic peptides (cyclopeptides) from natural sources have become a propitious lead candidate for developing therapeutic agents, including drugs for cancer treatment. This mini-review highlights cyclopeptides from microbial-derived natural products that have demonstrated significant cytotoxicity or anticancer activities. A literature search for the potent anticancer cyclopeptides isolated in the recent decade from fungi and bacteria from both terrestrial and marine origins was carried out. A total of eighty-three papers from 2000-2020 were summarized. The primary information from the literature was elicited, and the recently selected examples of anticancer cyclopeptides (2010-2020) are discussed herein. Moreover, this mini-review also provides a look into the mode of action of anticancer cyclopeptides. Naturally occurring cyclopeptides with canonical and non-canonical amino acids isolated from fungi, myxobacteria, actinomycetes, marine cyanobacteria, and microbes associated with marine organisms and their anticancer activity are featured herein.