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A new group of bioinspired ionic liquids (ILs) based on glycine betaine and natural or synthetic anions was synthesized. The developed synthesis methods enabled the preparation of designed salts with...

Herbicides such as (3,6-dichloro-2-methoxy)benzoic acid (dicamba), (4chloro-2-methylphenoxy)acetic acid (MCPA), (2,4-dichlorophenoxy)acetic acid (2,4-D), or (±)-2-(4-chloro-2-methylphenoxy)propionic acid (MCPP) are applied in the form of sodium, potassium, ammonium salts, or esters. Although esters are more biologically active, the downside is their high volatility, which is a hazard to neighboring dicotyledonous plants and spraying workers. Moreover, their commercial preparation requires the use of adjutants, which improve the wettability of the sprayed surfaces. Herbicidal ionic liquids (HILs) were introduced to overcome such drawbacks and proved to be more effective in terms of controlling weeds compared to currently applied commercial preparations. In this study, we investigated the concept of herbicidal ionic liquids that contained dicamba in a surface-active cation as an ester substituent as well as (4-chlorophenoxy)acetic acid (4-CPA), 2,4-D, MCPA, MCPP, and clopyralid as anions. The synthetized compounds were characterized in terms of surface and antimicrobial activity as well as herbicidal efficacy against garden cress (Lepidium sativum). Moreover, hydrolysis was performed using acidic, neutral, and alkaline treatments to check the conditions under which dicamba is released from the esterquat. It was revealed that the obtained HILs exhibited excellent surface properties manifested as a tendency to effectively interact with biological membranes at lower doses. This was observed as increased toxicity in comparison to reference herbicidal formulations during direct exposure; however, assessment of microbial activity in soil revealed that the ecotoxic effect was limited, most likely due to marginal mobility. Consequently, the tested HILs effectively reduced garden cress biomass production and were notably less volatile compared to commercial herbicides. Our findings present a sustainable concept of more effective usage of well-known herbicides with simultaneous reduction of the environmental burden by limiting the amount of chemicals intentionally introduced for agricultural purposes.

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Natural auxins are a group of plant hormones that affect plant growth and development. The most common auxin is indole-3acetic acid (IAA), which is mainly synthesized from tryptophan. Since converting synthetic auxins into an ionic liquid increases their herbicidal activity, an attempt was made to synthesize new amino acid ionic liquids (AAILs) with l-tryptophanate anions. As a result of the synthesis, two homologous series, tetraalkylammonium l-tryptophanates and dialkyldimethylammonium l-tryptophanates, were obtained with yields exceeding 95 %. For the obtained AAILs, basic physicochemical properties (solubility in solvents of different polarity, thermal stability, phase changes, and surface activity) were determined, and whether the obtained salts act as growth stimulants for lettuce (Lactuca sativa L.) was evaluated. The transformation of l-tryptophan into AAILs improved the physicochemical properties and increased the auxin activity. In addition, the higher content of nutrients (micro-and macroelements) made lettuce a healthier food product.

The surface activity of dicationic ionic liquids is described in this paper. The basic interfacial parameters including critical micelle concentration (CMC), surface tension at the CMC (γ CMC), the adsorption efficiency (pC20), surface excess (Γmax), the minimum surface occupied by a single molecule (A min), and Gibbs energy (ΔG 0 ads) were investigated and compared. Basically, we wanted to extend our previous study on dicationic ionic liquids with bis-ammonium cation. Knowing that, the compounds obtained are effective in limiting the feeding of adult and larvae confused flour beetle (T. confusum), it was decided to correlate the deterrent activity with the surface properties of analyzed dicationic ionic liquids. Accordingly, it was found that the deterrent activity of the studied compounds increases with increasing wetting ability.

In this study, a series of 10 novel 1-methyl-3-octyloxymethylimidazolium derivatives carrying various anionic moieties (4-hydroxybenzenesulfonate, benzenesulfonate, carvacroloxyacetate, chloride, formate, propionate, thymoloxyacetate, vanillinoxyacetate, eugenoloxyacetate and trimethylacetate) were synthesized. Compounds were tested for their antimicrobial activity against six microbe strains (Staph-ylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumoniae, Escherichia coli, Enterococcus faecalis, and Candida albicans), cytotoxic activity against the mouse melanoma cell line (B16 F10), and surface active properties. All synthesized compounds exhibited antimicrobial activity (expressed as minimum inhibitory concentration; in range of 0.10–27.82 mM/L), especially against Gram-positive bacteria and fungi. In addition, all compounds demonstrated cytotoxicity on B16 F10 cells (IC50 values 0.0101–0.0197 mM/L). Surface properties defined as CMC values, ranged from 0.72 to 32.35 mmol L-1. The obtained results provide an insight into the promising activity of a novel group of quaternary imidazolium derivatives having ionic liquid properties. The most potent compounds, containing a thymoloxyacetate and eugenoloxyacetate moiety, could be candidates for new antimicrobial agents or surfactants.