This study presents the properties of a new group of ionic liquids (ILs) based on various cations and pelargonic acid, a natural nonselective herbicide. The obtained bio-ILs were obtained with high yield (>92%) using a metathesis reaction or neutralization of quaternary ammonium hydroxides and characterized in terms of physicochemical properties. Tests under greenhouse conditions confirmed the superior herbicidal activity of ILs compared to pure pelargonic acid, especially against white mustard (5–10-fold higher efficacy of ILs). Further studies under field conditions revealed that tetrabutylammonium, benzalkonium, and oleyltrimethylammonium pelargonates exhibited the highest efficiency (50.5%, 49.5%, and 46.7%, respectively) at an approximately 3-fold lower dose of pelargonic acid (2.72 kg per 1 ha) compared to that used in commercial products (8–11 kg per 1 ha). This allows classification of the synthesized ILs as bioherbicidal ionic liquids (bio-HILs). In addition to bio-HILs, two new auxins were also obtained. Evaluation of antimicrobial activity indicated that the most potent effect was observed in the case of salts with oleyltrimethylammonium and tallowtrimethylammonium cations [minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and minimum fungicidal concentration (MFC) values lower by 2 orders of magnitude compared to pelargonic acid]. The fundamental influence of the cation was also observed during biodegradability assay, as the results varied from 0% to 85% (the highest biodegradability was observed in the case of dodecylbetainium and tetrabutylammonium pelargonates). The computational data suggested that biodegradation efficiency seems to be influenced by the interactions between the cation and the anion. The performed toxicity tests allowed classification of the obtained bio-HILs as category V [di(hydrogenated tallow)dimethylammonium pelargonate] or category IV compounds against rats.
Phytohormones are chemical substances that regulate plants growth, reproductive processes, longevity, development, and even death. One of the most common representatives of this group is indole-3-butyric acid (IBA), which is widely applied in various branches of agriculture. Taking into consideration that the conversion of conventional herbicides into ionic liquids leads to the enhancement of their biological activity, we decided to implement the same strategy for selected phytohormone. Hence, we synthesized a homologous series comprising alkylated choline cations and indole-3-butyrate anions. The new biobased ionic liquids (ILs) were characterized in terms of physicochemical properties (thermal stability, phase transitions, solubility, surface activity, density, and viscosity) and susceptibility to biodegradation according to the OECD 301 F test. Subsequently, their activity as a growth stimulator was evaluated for butterhead lettuce (Lactuca sativa L.) as a test plant. Additionally, the nutrient assimilation by the test plants was analyzed. The study revealed that the IL containing cations with octyl groups, at the optimal concentration of 0.5 ppm, enhanced lettuce biomass production by approximately 21% compared to that of the control. Moreover, the lettuce was enriched with valuable micro- and macroelements, such as P, K, Ca, Mg, Na, and Mn. These findings comply well with the concept of sustainable agriculture focused on utilizing environmentally friendly compounds derived from sources of natural origin while exhibiting enhanced efficacy.
This study is focused on the utilization of naturally occurring ascorbic acid (vitamin C) in the synthesis of biologically inspired ionic liquids with attractive application potential. The ionic liquids with the ascorbate anion were obtained in high yield (>90%) via a simple, "green" two-step procedure using well-known, cost-effective, and commercially available alkyltrimethylammonium, dialkyldimethylammonium, and alkylmethylbis(2hydroxyethyl)ammonium cations. Three positive ions in this group used for syntheses are derived from renewable resources, such as vegetable oil or animal fat. The study confirmed the strong influence of the chemical structure of the cation on the stability of the compounds obtained in the air, as well as in aqueous solutions. In addition, the synthesized ionic forms of vitamin C exhibited very good antibacterial and antifungal properties against different microorganisms, including pathogens. The tests also revealed the excellent or good deterrent activity toward common stored-grain insects (granary weevil, confused flour beetle, and khapra beetle), reaching the values determined for azadirachtin, known as the reference antifeedant. The best results were achieved with products containing two long alkyl substituents in the cation (dimethyldioctylammonium and didecyldimethylammonium) that proved to be extremely effective against all the organisms tested. The results of the biological activity indicate that the products synthesized belong to the third generation of ionic liquids. In conclusion, ascorbate-based ionic liquids with multifunctional (antibacterial, antifungal, antifeedant, and antioxidant) properties have substantial potential to be used in the storage of crop protection products.
Dicamba is a widely applied herbicide for crop protection and has potential for volatility. New formulations containing dicamba with greatly reduced volatility, introduced to the market in 2017, still caused foliar injury to crops and other plants in Arkansas and neighboring states in the United States. In response, we proposed the transformation of dicamba into protic as well as aprotic dicamba-based organic salts called herbicidal ionic liquids (HILs). All of the HILs were characterized by high stability, whereas the biological activity of the most effective products, evaluated during greenhouse studies, was found to be greater than that of currently used commercial analogues. Furthermore, the possibility of introducing an alkyl chain of a specific length allows one to obtain plant protection products with the desired physicochemical properties while maintaining herbicidal effectiveness. These studies are expected to aid in the design and development of new herbicidal formulations, which, depending on the weed species, could increase the efficacy of the applied active ingredient. Simultaneously, the volatility of the synthesized compounds, particularly those containing quaternary ammonium cations, was multiple times lower than that of the free acid of dicamba. This strategy minimizes the risk of off-site movement via volatilization, which may cause significant damage to neighboring broadleaf crops and pose a threat to existing ecosystems.
Natural origin ammonium salts or binary mixtures including indole-3-butyric acid as novel plant growth regulators.
In this study, new quaternary bis(ammonium) salts with alkyl-1,X-bis(dimethyldecylammonium) cation and saccharinate, acesulfamate, lactate and pyroglutamate anions were synthesized and characterized by 1H and 13C NMR spectroscopy. Thermal gravimetric and differential scanning calorimetry analyses confirmed that all salts were thermally stable and the majority of them exhibited melting points below 100 °C. The physicochemical properties (viscosity, density, refractive index values, and solubility) of the obtained salts were determined for three compounds with lactate anions. All the tested salts have suitable properties which, in practical application, will reduce the losses caused by the most important storage insects. Most of the synthesized ionic liquids had comparable or better deterrent activity than azadirachtin—an alkaloid known as the most active antifeedant.Graphical abstract Electronic supplementary materialThe online version of this article (10.1007/s11696-018-0495-6) contains supplementary material, which is available to authorized users.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
334 Leonard St
Brooklyn, NY 11211
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.