Conversion of l‐Tryptophan Derivatives into Biologically Active Amino Acid Ionic Liquids

Abstract

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.

Bifunctional Double-Salt Ionic Liquids Containing both 4-Chloro-2-Methylphenoxyacetate and l-Tryptophanate Anions with Herbicidal and Antimicrobial Activity

“…The conversion of l -tryptophan to an ion reduced its chemical stability, which was also observed in our previous research regarding amino acid ILs with tetraalkylammonium cations. 18 , 19 A comparison of the NMR spectra of DSIL 12 and its degradation products is shown in Figures S75 and S76 .…”

“… 17 A convenient method of obtaining ammonium salts with an l -tryptophanate anion, which shows plant growth regulation activity and improved physicochemical properties, was described in previous reports. 18 , 19 Herbicidal ionic liquids (HILs) are a new approach to known bioactive compounds. The latest reviews outline the broad scope of this research topic, which provides numerous opportunities that still lie ahead of researchers in this field.…”

“…Ammonium salts containing the IBA anion and an amino acid cation show regulatory properties toward germination and shoot and root development . A convenient method of obtaining ammonium salts with an l -tryptophanate anion, which shows plant growth regulation activity and improved physicochemical properties, was described in previous reports. , Herbicidal ionic liquids (HILs) are a new approach to known bioactive compounds. The latest reviews outline the broad scope of this research topic, which provides numerous opportunities that still lie ahead of researchers in this field. , HILs that incorporate many herbicidal anions have been investigated, including MCPA, 2,4-D, dicamba, 2,4-DP, nicosulfuron, and a nonselective pelargonate of natural origin .…”

Synthesis and Surface Properties of Piperidinium-Based Herbicidal Ionic Liquids as a Potential Tool for Weed Control

“…Surface excess concentrations at the saturated interface (Γ max ), the minimum surface occupied by a molecule at the interface ( A min ), Gibbs free energy of the adsorption layer (Δ G 0 ads ), CMC/C 20 ratio, and the adsorption efficiency, pC 20 , have been presented in our previous reports. ,, …”

The role of indole derivative in the growth of plants: A review

“…A class of ionic liquids (ILs) 11 ( Figure 1 ) that demonstrate good solubility was developed by incorporating ammonium cations into the structure of L-Trp. The utilization of Lettuce increases its biomass by a range of 12-20% and enhances the uptake of certain nutrients ( Szymaniak et al., 2021 ). Jasmonoyl-L-Tryptophan (JA-Trp) 12 ( Figure 1 ) is a class of compounds that has the ability to disrupt AUX1, thus resulting in a failure of IAA.…”