NATURAL OCCURRING BIOANTIOXIDANTS COMPLEXED WITH B-CYCLODEXTRIN AND THEIR EVALUATION AS INSECT REPELLENTS

Caffeic acid, p-coumaric acid, curcumin, eugenol and zingerone are bioantioxidants whose antioxidant action js analysed in relation to the medium by which they interact.1 They are secondary metabolites of plants where they have an important role in defence against pathogens and parasites. Daily, these metabolìtes have been taken because present jn food we eat. Due to their market availability, healthpromoting activities and edibjlity, these compounds can have potential applications in fields where safety oral ihtake js required. Orosophi./a suzuk;.t` (Matsumura) (Diptera Drosophmdae), spotted-wing drosopmla, has recently become a common and serious pest of temperate frujt crops (small fruits, cherries and kaki) Ìn many countries.2 Crop damage is caused when adult females, using a serrated ovipositor, Iay eggs in ripe and partially ripe fruit just before harvest. Push-pull strategies (stimulus deterrent diversionary strategies) attempt to reduce crop injury by modifying pest distribution using adversative stimulj to push the pest organism away from the crop while also using attractive stimuli to pull the pest organism out of the crop.3 A novel and more sustainable method for repelling D. suzuk/./. was evaluated by spraying edible repellents (alone and jn mixture) on fruit surface during ripening period in combination with conventional natural attractive traps. Caffeic acid, p-coumaric acid, curcumjn, eugenol and zingerone were selected as insect repellent in combinatjon with natural edible synergists in order to enhance repellent activity. With the aim to protect the insect repellent from light and envjronmental degradation, inclusion complexes with P-cyclodextrin (PCD) were prepared under sustainable conditions. P-CD is an amphipathic toroid consisting of seven D-(+)-glucopyranose units linked by a-(14) bounds with an outer hydrophilic surface and a hydrophobic cavjty that Ìs capable of forming inclusion complex with hydrophobic guests of suitable size and shape.4 P-CD has the ability to fom inclusion complexes resulting in significant improvement Ìn water solubility and stability of the guest molecule whose taste and odor are partially masked. P-CD is food-approved and is produced from staich by a sustainable biotechnological process. Preliminary studies on effectiveness of complexes were carrjed out with laboratory-reared D. st/zuk/./. on artificjal fruits. Under electrophysiologjcal assay D, suzuk/./. appeared to be sensitive to all selected edible repellents. Field experiments have been.planned. The project, started in March 2018, join expertises in organic chemistry, physjcal chemistry, entomology, insect physiology and crop protection