Biosynthesis and biological activity of enniatins.

Enniatins are N-methylated cyclohexadepsipeptides (CHDPs), composed of three units each of N-methylated branched-chain L-amino acid and D-2-hydroxy acid arranged in an alternate fashion. These low-molecular secondary metabolites are produced by Fusarium species, typical mycotoxin producing fungi. Enniatins are known for their ionophoric, phytotoxic and anthelmintic effect, antibiotic activity and recently their potent cytotoxic activity against cancer cell lines was shown. They act also as inhibitors of drug efflux pumps. Biosynthesis, biological activity, and the structural characteristics of these microbial metabolites were summarized in this review.