Lipase-Mediated Mechanoenzymatic Synthesis of Sugar Esters in Dissolved Unconventional and Neat Reaction Systems

Abstract

Mechanochemical and biocatalytic approaches in modern research are two major assets to develop greener processes. In the present study, these modular tools of sustainability are pointed toward the production of versatile and daily employed compounds such as surfactants. Toward this aim, glycolipids, a class of nonionic surfactants composed of ubiquitous and primary metabolites such as sugar and fatty acid moieties, represent a promising alternative to petroleum-derived surface-active agents. Therefore, the combination of biocatalysis with mechanochemistry aiming at glycolipid synthesis seemed a logical step that was taken in this study for the first time. The monoacylated model compound glucose-6- O -decanoate was synthesized with the help of a bead mill apparatus using two different unconventional dissolved reaction systems, namely, menthol-based hydrophobic deep eutectic solvents and 2-methyl-2-butanol, thus reaching up to 12% yield in the latter based on the conversion of vinyl decanoate, after only 90 min of reaction. In addition, a neat reaction system using an excess of vinylated fatty ester as an adjuvant allowed a 27 mM/h space-time yield. The overall significant increase in productivities, up to 6 times, compared to standard heating and shaking methods, shows the tremendous potential of mechanoenzymatic synthesis.

Rhamnopyranoside-Based Fatty Acid Esters as Antimicrobials: Synthesis, Spectral Characterization, PASS, Antimicrobial, and Molecular Docking Studies

“…The results are listed as Pa (probability for an active compound) and Pi (probability for an inactive compound). In the present study, Pa and Pi for different stearates (4)(5)(6)(7)(8)(9)(10)(11) are summarized in Table 2. Its FT-IR spectrum (Figure S28) had no OH stretching bands, indicating hexanoylation of the molecule.…”

“…The results are listed as Pa (probability for an active compound) and Pi (probability for an inactive compound). In the present study, Pa and Pi for different stearates (4)(5)(6)(7)(8)(9)(10)(11) are summarized in Table 2. PASS biological analysis (Table 2) indicates 0.57 < Pa < 0.62 for antibacterial and 0.68 < Pa < 0.73 for antifungal, suggesting that the rhamnose stearates 4-11 should be more active against fungal organisms than bacterial pathogens.…”

“…Sample Availability: Samples of the compounds (4)(5)(6)(7)(8)(9)(10)(11) are available on request from the authors.…”

“…These drugs often depend on (i) sugar linkage, (ii) esterified/protected hydroxyl group(s), and (iii) unesterified/unprotected hydroxyl group(s) [ 9 , 10 ]. These elements are known to increase a substance’s aqueous solubility, stability, and biocompatibility, which helps the medicine reach its intended target site and improves absorption [ 11 ]. For instance, compared to aspirin alone, the anticancer activity and water solubility of the glucose-aspirin ester were improved eight to nine times and seven times, respectively [ 12 ].…”

Deep Eutectic Solvents for the Enzymatic Synthesis of Sugar Esters: A Generalizable Strategy?

“…The use of other, more benign, organic solvents like tertiary alcohols or ketones has been reported as well, but it generally results in low yields and/or very long reaction times due to the very low solubility of sugars (especially disaccharides as lactose) in these solvents. ,, Sugar derivatizations can be performed to enhance carbohydrate solubility in organic media (e.g., for lactose oleate), yet at the cost of establishing multi-step and cumbersome processes. In this context, the use of non-conventional media like ionic liquids and deep eutectic solvents (DESs) has been proposed as a promising alternative to organic solvents. − …”