N-Methyl-L-glutamine

The facile reaction of a readily available aminopolyol from the chiral pool, N-methyl-d-glucamine, which avoids the side reactions usually associated to anomers of amino sugars, with epoxide and polyepoxide derivatives, enables the preparation of new non-ionic surfactant-like structures combining hydrophilic and hydrophobic moieties. The molecular architectures thus obtained range from linear to tripodal and pyramidal structures. The resulting substances containing multiple chiral centers exist as diastereomeric mixtures, for which various conformations are likewise possible by virtue of inter-chain interactions. The stability and chirality preferences of all possible stereoisomers have been evaluated in detail by DFT methods. Given the amphiphilic structure of both protected and O-protected derivatives obtained by acetylation, self-aggregation could eventually lead to solvent entrapment. Unfortunately, only one compound behaves as efficient hydrogelator and DMSO-gelator at low concentrations. The issue is also discussed in terms of the different molecular arrangements.

Polymeric resins are practically important adsorbents in a wide variety of applications, but they generally suffer from low surface areas and limited functionalized adsorption sites owing to their closely compacted and tangled polymeric chains. A metal-organic framework (MOF)-polymer composite with enhanced adsorption capacity against the compacted polymeric resins was reported. The strategy to incorporate functionalized oligomer within the cavities of the MOF was demonstrated by the preparation of MIL-101(Cr) incorporated with N-methyl-d-glucamine-based organosiloxane polymer. The resulting MOF composite shows high efficiency for the removal of boric acid from water because of exceptionally high loading of functional groups responsible for the boron adsorption. This material offers promising perspectives for boron removal applications in seawater desalination.

Click chemistry refers to a group of reactions that are fast, simple to use, easy to purify, versatile, regiospecific, and give high product yields. Therefore, a novel, efficient magnetic nano-sorbent based on N-methyl-D-glucamine attached to magnetic nanoparticles was prepared using click coupling method. Its boron sorption capacity was compared with N-methyl-D-glucamine direct attached nano-sorbent. The characterization of the magnetic sorbents was investigated by several techniques such as X-ray diffraction, scanning electron microscope, transmission electron microscope, dynamic light scattering, thermogravimetric analysis, Fourier transform infrared spectrophotometer, and vibrating sample magnetometer. The boron sorption capacity of sorbents was compared by studying various essential factors influencing the sorption, like sorbate concentration, sorbents dosage, pH of the solution, and contact time. Langmuir and Freundlich and Dubinin-Radushkevich adsorption isotherms models were applied. Percent removal and sorption capacities efficiencies of sorbents obtained with direct and click coupling are found to be 49.5%, 98.7% and 6.68 mg/g, 13.44 mg/g respectively. Both sorbents have been found to be compatible with Langmuir isotherm, and the boron sorption kinetics conforms to the pseudo second order kinetics. The reusability study of sorbents was carried out five times for boron sorption and desorption.