Unveiling the role of the ring size in the sugar-based tensides surfactancy by interfacial studies and molecular dynamics

• Published in: Journal of molecular liquids 2024-08, Vol.408, p.125350, Article 125350
• Main Authors: Sangiorgio, Sara, Pargoletti, Eleonora, Ballabio, Giorgia, Rabuffetti, Marco, Cappelletti, Giuseppe, Raimondi, Laura, Speranza, Giovanna
• Format: Article
• Language: English
• Subjects: Chemoenzymatic synthesis; Computational studies; Solvation energies; Sugar-based surfactants; Water-in-oil emulsions
• ISSN: 0167-7322; 1873-3166
• DOI: 10.1016/j.molliq.2024.125350

[Display omitted] •A library of glucose-based Sugar Fatty Acids Esters (SFAEs) was prepared by a two-step chemoenzymatic process.•Isolated glucopyranosides esters showed a better interfacial tension reduction capability with respect to that of the corresponding glucofuranosides.•Water-in-oil emulsion stability tests resembled the different surfactancy of the two surfactant families.•Computational studies corroborated the role of the ring size on the emulsifying properties of the bio-based surfactants. Sugar Fatty Acid Esters (SFAEs) are a class of biosurfactants that are gaining growing attention due to their excellent emulsifying, stabilizing and detergency properties; moreover, they show several advantages over their petroleum-based counterparts being non-toxic, fully biodegradable and environmentally friendly. Herein, a series of alkyl 6-O-palmitoyl-D-glucosides were enzymatically synthesized by reacting alkyl D-glucoside isomeric mixtures with molten palmitic acid in an easily scalable solvent-free system. Couples of anomers, namely pyranosides- (Py) and furanosides-based compounds (Fu), were isolated through flash column chromatography. Investigation of interfacial tension (IFT), water-in-sunflower oil (W/O) emulsifying capability and subsequent stability over time by turbidimetric and confocal microscope analyses indicated strong differences in their physico-chemical properties, with Py-derivatives showing better surfactancy with respect to that of Fu ones. Furthermore, computational studies were performed aiming at both unravelling the role of ring size (Py vs Fu) in the surfactant mixtures and at evaluating the water-in-oil emulsion formation and stabilization.