Plants produce a variety of secondary metabolites, many of which increase plant resistance against herbivores and pathogens. Within this project, we aim at deciphering the structure, biosynthesis, behavior and ecological effects of various classical and novel secondary metabolites, including maize benzoxazinoids and dandelion sesquiterpene lactones. We use a combination of approaches, including organic chemistry, analytical chemistry, molecular biology, genetics and bioassays to understand how secondary metabolites govern the life of plants.