The present study is focused on the utilization of naturally occurring abietic acid in the synthesis of high added-value compounds with attractive characteristics. The synthesis of ILs derived from abietic acid was conducted using ion-exchange or neutralization methods, and the products were obtained with high yields exceeding 85%. The study confirmed strong influence of the chemical structure on the physicochemical properties of the obtained compounds, such as solubility, thermal stability, and phase transitions. The results also revealed excellent deterrent properties of ILs with abietate anions toward S. granarius, T. conf usum, and T. granarium, reaching or exceeding the values calculated for azadirachtin. The best results were achieved for cations containing long alkyl substituentstetraalkylammonium and 1-alkyl-3-methylimidazolium cations. Additionally, the obtained compounds exhibited antioxidant properties in the DPPH radical scavenging assay. The highest activity was observed for tetraalkylammonium cations. The obtained results allow for a conclusion that abietate ionic liquids with both antifeedant and antioxidant activity can be successfully implemented into storage crop protection.

This study presents a new group of herbicidal ionic liquids (HILs) based on a cation occurs commonly in nature−acetylcholine. The HILs were obtained with a high yield through ion exchange between acetylcholine chloride and potassium or sodium salts of selected acids with herbicidal activity. The results of the herbicidal activity measurement against common oilseed rape (Brassica napus L.) exceeded those of the commercial products. Spray solutions of the synthesized HILs revealed high surface activity and wetting properties which further manifested as higher herbicidal activity. The reduction of surface tension and low contact angles together with the specific action of acetylcholine allowed for better penetration of synthesized HILs into plant tissues. In addition, OECD 301F tests confirmed high mineralization of the HILs. The simple transformation of commercial herbicides into acetylcholine HILs proved to be a very effective method of increasing their activity, and constitutes an interesting solution to the problem of weed infestation with the use of a substance commonly found in nature.