Terpene profiling of full-blooming inflorescences of Helichrysum italicum populations from Elba, Capraia and Giglio Islands (Tuscan Archipelago, Italy)

This study explores the terpene variability of full-blooming inflorescences of Helichrysum italicum subsp. italicum across twelve populations from the three major islands of the Tuscan Archipelago (Elba, Capraia, and Giglio). A total of 316 plants were sampled for the GC/MS analysis of terpene content. We identified a total of 41 compounds, of which 20 were monoterpenes and 21 were sesquiterpenes. We found a substantial variability in the terpene content across populations growing on the three investigated islands. Overall, the findings indicated that the extent of chemical variability was more pronounced among different populations than within individual populations. Furthermore, populations originating from the same island did not exhibit a consistent tendency to form island-specific clusters, but were instead distributed across distinct groupings. Two main chemotypes were characterized: one dominated by α-pinene and limonene, and another by neryl acetate, nerol derivatives, and γ-curcumene. Some populations exhibited significant chemical variability, suggesting that both genetic and environmental factors play a role in shaping terpene profiles. The co-occurrence of bioactive compounds reinforces the pharmaceutical, cosmetic, and nutraceutical potential of the H. italicum terpene profile. Given the complexity of terpene biosynthesis, future studies in a controlled common garden experiment will be essential to determine the relative contributions of genetic heritage and environmental influences. This research provides a foundation for optimizing the cultivation and commercial applications of H. italicum in diverse industries.