Glucosinolate biochemical diversity and innovation in the Brassicales

► Glucosinolates are analysed from herbarium specimens of all families of the Brassicales. ► Basal Brassicales contain glucosinolates derived from BCAA and Phe. ► Core Brassicales exhibit repeated innovation in glucosinolate structures. ► Methyl glucosinolate occurs in Capparaceae, Cleomaceae and Forchhammeria. ► New World Capparaceae contain glucosinolates of complex and unresolved structures.