Antimicrobial peptides are small proteins used by the innate immune system to combat bacterial infection in multicellular eukaryotes. There is mounting evidence that these peptides are less susceptible to bacterial resistance than traditional antibiotics and that they may form the basis for a novel class of therapeutics. Systems and methods may treat the amino acid sequences of these peptides as a formal language and build a set of right-linear grammars that describe this language. These grammars may allow for rationally designed novel antimicrobial peptides in silico. These peptides conform to the syntax of natural antimicrobial peptides lack significant homology to any natural sequences, thus populating a previously unexplored region of protein sequence space. Synthesis of these peptides, leads to de novo AmPs.