Synthetic Tripodal Squaramido‐Based Receptors for the Complexation of Antineoplastic Folates in Water

Abstract

Three suitably oriented squaramido ammonium groups form the basis of the first abiotic receptor that employs the noncovalent ammonium–carboxylate electrostatic interaction and a hydrogen bond to achieve high‐affinity molecular recognition in water. These interacctions have been studied experimentally by isothermal calorimetry (ITC), NMR spectroscopy, and MS. Also, we have proposed a model for coordination from DFT calculations and NMR spectroscopy studies. Finally, a fluorimetric ensemble of the receptor with 5‐carboxyfluorescein was useful for the quantitative fluorimetric determination of folate and methotrexate in commercial samples using competition assays.

Selective Binding of Folic Acid and Derivatives by Imprinted Nanoparticle Receptors in Water

“…Folic acid ( 1 ) (Chart ) is an important biological molecule. Because folate receptors are overexpressed on many cancerous cells, folic acids are frequently used for targeted delivery of anticancer drugs. , The creation of synthetic receptors for folic acid illustrates the typical challenges in the molecular recognition of biomolecules in water. − The molecule is highly functionalized, with a glutamate coupled to a pteroate moiety. It is fully water-soluble with numerous hydrogen-bond donors and acceptors and two ionizable carboxylic acid groups.…”

Removal of Au3+ and Ag+ from aqueous media with magnetic nanoparticles functionalized with squaramide derivatives

“…With these experimental conditions we avoid obtaining the double entry product. 22,23 In this study, in addition to 3,4-dimethoxy dopamine, 2-(methylthio)ethan-1-amine, or 3-(methylthio)propan-1-amine have been used as sulfur derivatives to coordinate the FeNP. Finally, the di-squaramide – introduction of the second amine in the ring of the mono-squaramide – is obtained from the mono-squaramide using a more polar solvent, such as MeOH or EtOH, in the presence of an equivalent of another primary amine.…”

Chromogenic and fluorogenic chemosensors and reagents for anions. A comprehensive review of the years 2010–2011

“…189) was used together with 5-carboxyfluorescein (5-CF) for the development of a displacement assay for the recognition of the folate anion. 241 Water solutions of 5-CF buffered at pH 9.0 showed the typical emission band of the fluorophore at 525 nm upon excitation at 365 nm. Emission was quenched gradually upon the addition of increasing quantities of 379, leading to the formation of 1 : 1 complexes.…”