Synthesis, Crystal Structure and Biological Activity of 2-Hydroxyethylammonium Salt of p-Aminobenzoic Acid

Abstract

p-Aminobenzoic acid (pABA) plays important roles in a wide variety of metabolic processes. Herein we report the synthesis, theoretical calculations, crystallographic investigation, and in vitro determination of the biological activity and phytotoxicity of the pABA salt, 2-hydroxyethylammonium p-aminobenzoate (HEA-pABA). The ability of neutral and anionic forms of pABA to interact with TIR1 pocket was investigated by calculation of molecular electrostatic potential maps on the accessible surface area, docking experiments, Molecular Dynamics and Quantum Mechanics/Molecular Mechanics calculations. The docking study of the folate precursor pABA, its anionic form and natural auxin (indole-3-acetic acid, IAA) with the auxin receptor TIR1 revealed a similar binding mode in the active site. The phytotoxic evaluation of HEA-pABA, pABA and 2-hydroxyethylamine (HEA) was performed on the model plant Arabidopsis thaliana ecotype Col 0 at five different concentrations. HEA-pABA and pABA acted as potential auxin-like regulators of root development in Arabidopsis thaliana (0.1 and 0.2 mM) and displayed an agravitropic root response at high concentration (2 mM). This study suggests that HEA-pABA and pABA might be considered as potential new regulators of plant growth.

p-Aminobenzoate Organic Salts as Potential Plant Growth Regulators for Tomatoes

“…Thus, benzoic acids, well-known for their importance as building blocks in drug development, gained increasing attention in plant science, being involved in various physiological processes from the regulation of seed germination [5][6][7] to disease resistance and stress tolerance in plants [8,9]. Among these compounds, p-aminobenzoic acid (pABAH) is a well-known natural metabolite present in plant and animal tissues, widely described in literature as a precursor of folic acid [10] and recently of coenzyme Q [11].…”

Molecular Dynamics Simulations of p97 Including Covalent, Allosteric and ATP-Competitive Inhibitors

“…An extended discussion on this topic can be found in literature. [26][27][28][29][30] The starting structures of the complexes containing the inhibitor molecules NMS-873, NMS-322 and NMS-859 (non covalently bound, see discussion) were generated by molecular docking with QXP v0705 program 31 setting the following parameters to the mcdock tool: in house modified QXP MacroModel forcefield, 1500 Monte Carlo steps saving 20 poses for visual inspection. The rather large number of poses saved enabled a procedure identifying orientations compatible with photo-affinity labeling experimental evidence reported by Magnaghi et al, 2013.…”

4-Aminobenzoic Acid Derivatives: Converting Folate Precursor to Antimicrobial and Cytotoxic Agents

“…However, PABA is neither essential nor biosynthesized in mammals. It is produced by symbiotic bacteria, especially Escherichia coli and absorbed from dietary intake [1][2][3][4][5].…”

“…PABA demonstrated also properties of cytoprotective agents [7] and direct anticoagulants [2]. PABA-based diagnostic tests of gastrointestinal tract state have been developed [4,8]. The potassium 4-aminobenzoate is used for the treatment of mainly dermatologic disorders such as scleroderma, dermatomyositis and Peyronie's disease [3].…”

“…The potassium 4-aminobenzoate is used for the treatment of mainly dermatologic disorders such as scleroderma, dermatomyositis and Peyronie's disease [3]. In agriculture, PABA has displayed the promotion of resistance against plant bacterial and viral pathogens and plant growth modulator properties [4].…”