Daniel Jacobi, Christian Zidorn
Eighteen years after the first original overview about sesquiterpene lactones in the Cichorieae tribe of the Asteraceae family and seven years after its first update, a second updated version of this review is presented. All chemophenetically relevant reports on sesquiterpene lactones and their immediate precursors reported in the tribe that were published between the years 2018 and 2025 are presented and an overview of all sesquiterpene lactones that have been reported in the Cichorieae is given. The analysis of the data led to 1) an updated general overview of the reported sesquiterpene lactones in the different genera, 2) a chemophenetic overview of the distribution of particular sesquiterpene lactone classes within the different subtribes of the Cichorieae, and 3) a discussion of the insights based on all the available data (i.e., the data of the original review and its two updates together). In the last eight-year period, 108 previously undescribed sesquiterpene lactones and their immediate precursors (+ 23 %) were reported. Thus, a total of 582 sesquiterpene lactones and precursors are currently known from the tribe Cichorieae. The number of source species from which sesquiterpene lactones have been reported increased from 157 to 208 (+ 32 %). However, for only one third of the approximately 100 genera in the Cichorieae sesquiterpene lactone have been reported in the literature. Nonetheless, for the remaining 67 genera, the occurrence of, also previously undescribed, sesquiterpene lactones seems likely. The aim of the review at hand is to highlight the gaps to be filled, aid in prioritizing taxa to be studied, and to serve as an indirect help for structure elucidation for not yet described natural compounds.