Three unnatural lysergic derivatives belonging to the class of ergopeptines have been obtained by feeding L-norvaline to a strain of Claviceps purpurea. Ergorine [1] corresponds to an analogue of ergovaline, and ergonorine [2] is an analogue of ergocornine; both have at C-5′ an n-propyl substituent instead of an isopropyl group. Ergonomorine [3] has the npropyl group at C-2′ and C-5′ as well. This alkaloid represents the first example of an ergopeptine having an unnatural amino acid in the first position of the cyclol moiety. Additional feeding experiments with natural and unnatural amino acids indicated the maximum possible size of the substitutent in the first position of the peptide moiety. © 1992, American Chemical Society. All rights reserved.