Encapsulation of inuloxin A, a plant germacrane sesquiterpene with potential herbicidal activity, in beta-cyclodextrins

Inuloxin A is a promising plant phytotoxic sesquiterpene that deserve further studies to evaluate its potential as a bioherbicide. However, its low solubility in water and bioavailability could hamper its practical application. For this reason, inuloxin A was complexed with ?-cyclodextrins by using three different methods, i.e.: kneading, co-precipitation and grinding. The resulted complexes were fully characterized by different techniques as 1H NMR, UV-vis, XRD, DSC and SEM, and biologically assayed in comparison with the pure compound in several biological systems. The efficacy of the kneading and grinding complexes was similar to inuloxin A and almost completely inhibit the Phelipanche ramosa seed germination. The complete solublity in the water and the preservation of the biological properties of these two complexes could allow further studies to develop a novel natural herbicide for parasitic plant management based on these formulations.