Efrapeptins are peptides produced by fungi in the genus Tolypocladium that have antifungal, insecticidal, and mitochondrial ATPase inhibitory activities. They are produced via a biosynthetic pathway similar to but simpler than the Ciclosporin pathway, with nonribosomal peptide synthase (NRPS) and/or polyketide synthase (PKS) being the key elements. Efrapeptins are peptides produced by fungi in the genus Tolypocladium that have antifungal, insecticidal, and mitochondrial ATPase inhibitory activities. They are produced via a biosynthetic pathway similar to but simpler than the Ciclosporin pathway, with nonribosomal peptide synthase (NRPS) and/or polyketide synthase (PKS) being the key elements.