Preparation and characterization of sustainable osthole@guar gum composite film and antifungal mechanism against Ustilaginoidea virens

The purpose of this study is to develop a new safe and sustainable technology to reduce the excessive dependence on chemical pesticides in crop protection fields. Ost-HP-β-CD inclusion complex was prepared using osthole (Ost) and hydroxypropyl-β-cyclodextrin (HP-β-CD) as ingredients that were added into guar gum film (GG film) to develop osthole@guar gum composite film. The results suggest that the characteristic peaks of Ost were detected in Ost@GG composite film, and its thermal stability was superior compared to Ost. The inhibition rate of Ost@GG composite film 200 times solution on conidia and hyphae of Ustilaginoidea virens was 100%, which was significantly higher than that of GG film and Ost-HP-β-CD inclusion complex at the same dilution times. Ost@GG composite film might destroy cell wall of U. virens causing leakage of intracellular contents and cell death. Ost@GG composite film has exceptional properties and antifungal activity U. virens.