Study of the Influence of Pure Ionic Liquids on the Lipase-catalyzed (Trans)esterification of Mannose Based on their Anion and Cation Nature

A screening of nine ionic liquids (ILs) has been carried out in order to study the influence of the anion's and cation's nature and structure on the synthesis of mannosyl myristate by (trans)esterification catalyzed by Novozym® 435. The best ILs in terms of yield (η) and initial rate (v0) are those based on the TFO- anion. The 24h yield (24h-η) reached 64.9% in [Bmim][TFO] and 70.9% in [Bmpyrr][TFO] by transesterification while it reached 29.7% and 44.5% respectively in each IL by esterification. [Bmpyrr][TFO] based on the pyrrolidinium cation gave the best results although this cation has been rarely used for biocatalysis. This work has thus highlighted a cation that could be further studied in biocatalysis of glycosylated compounds. The study of the relationship between the structure of the ILs and the v0 and η for the biocatalysis of mannosyl myristate showed that the lipase effectiveness is influenced by the anions while the cations have an indirect influence on the interaction strength between Novozym® 435 and the anions