Lipase-mediated regioselective modifications of macrolactonic sophorolipids

Abstract

Chemoenzymatic synthesis and modification of well-defined macrolactonic sophorolipid (SLML) analogues via a series of successive regioselective de-esterification/transesterification reactions is investigated. Of the lipases screened, Candida antartica lipase-B (Novozyme-435) successfully deacylated the C-6′ acetoxy group of natural and peracylated SLMLs. Subsequent transesterification with acylating agents (esters of fatty acids) was successful only with the C-6′ deacetylated natural SLML providing an avenue to well-defined analogues of varying amphilicity. The macrolactonic motif was essential for enzymatic recognition of the sophorose rings of these complex glycolipids. In the absence of the lactonic motif, the peracylated sophorose rings are not deacylated, rather the carboxyl end of the non-lactonic forms that was preferentially transesterified. All macrolactonic derivatives were characterized by IR, 1 H, 13 C, 1 H-1 H and 1 H-13 C NMR spectroscopy, as well as HRMS where applicable.

Novozym 435: the “perfect” lipase immobilized biocatalyst?

“…332 N435 was the best among the studied lipases for the hydrolysis of the C-6′ acetoxy group of macrolactonic sophorolipid. 333 This product was later acetylated.…”

"Unlocking the potential of a glycolipid platform through chemical modification"

“…Head group modifications are typically performed by using enzymes (e.g. esterase and lipase) owing to their selective -in contrast to chemical modification -acylation capability of the primary hydroxyl groups on the sophorose head [12]. Therefore, the literature is scarce on the chemical modification of the sophorose head group.…”

Regioselective Protection and Deprotection of Nanocellulose Molecular Design Architecture: Robust Platform for Multifunctional Applications

“…5−7 To catch up with the rapid development and technological concept of modern functional nanomaterials, it is necessary to gain control over their molecular structure. 8,9 Lipids, 10 proteins, 11 pyridones, 12 furanes, 13 and graphene 14 have been regioselectively functionalized to enhance specific properties and provide new functionalities for advanced applications. 15 The precise control of the positioning of functional molecules on anhydroglucose units of cellulose chains has been suggested to play an important role in the achievement of reproducible properties of nanocellulose.…”

“…Nanofibrillated cellulose (NFC) has attracted much interest because of its unique mechanical and optical properties and its capacity to modulate its surface. − It has been reported that the combination of nanocellulose with functional polymers and/or nanoparticles has the potential to achieve enhanced properties and fully exploit its potential as a multifunctional platform. − To catch up with the rapid development and technological concept of modern functional nanomaterials, it is necessary to gain control over their molecular structure. , Lipids, proteins, pyridones, furanes, and graphene have been regioselectively functionalized to enhance specific properties and provide new functionalities for advanced applications …”