(R)-PAC Biosynthesis in [BMIM][PF6]/Aqueous Biphasic System Using Saccharomyces cerevisiae BY4741 Cells

Abstract

(R)-phenylacetylcarbinol or (R)-PAC is a pharmaceutical precursor of (1R, 2S) ephedrine and (1S, 2S) pseudoephedrine. Biotransformation of benzaldehyde and glucose by pyruvate decarboxylase produces (R)-PAC. This biotransformation suffers from toxicity of the substrate, product [(R)-PAC] and by-product (benzyl alcohol). In the present study, ionic liquid/aqueous biphasic system was employed to enhance (R)-PAC production. Fermented broth was the reaction medium in which Saccharomyces cerevisiae BY4741 was the source of pyruvate decarboxylase. Hydrophobic ionic liquid 1-butyl-3-methylimidazolium hexafluorophosphate ([BMIM][PF6]) was the non-aqueous phase in which toxic compounds reside. Biocompatibility of [BMIM][PF6] and adequate distribution coefficients of benzaldehyde, (R)-PAC and benzyl alcohol were determined. A Box-Behnken design and response surface methodology were used for the optimization of biotransformation variables in order to maximize (R)-PAC yield and productivity. The results showed higher (R)-PAC yield and productivity of ∼1.5-fold each in the biphasic biotransformation of phase volume ratio 0.05 as compared to the monophasic (conventional) biotransformation. Moreover, the level of major by-product benzyl alcohol was also 3.5-fold lower in biphasic biotransformation. [BMIM][PF6]/aqueous biphasic system is a new approach which could intensify the (R)-PAC production.

Production of Phenylacetylcarbinol via Biotransformation Using the Co-Culture of Candida tropicalis TISTR 5306 and Saccharomyces cerevisiae TISTR 5606 as the Biocatalyst

“…Similarly, Nunta et al [ 10 ] utilized the whole cells of C. tropicalis TISTR 5306 and Saccharomyces cerevisiae TISTR 5606 in the two-phase emulsion system for the production of PAC and found statistically significantly higher ( p ≤ 0.05) PAC levels in C. tropicalis when compared to S. cerevisiae. Other studies also featured the use of S. cerevisiae for PAC production [ 20 , 21 ]. Moreover, to achieve economic feasibility, researchers are also seeking ways to utilize cheap raw materials, such as agricultural and agro-industrial residues, over costly carbon sources, with the coupled production of several high-value chemicals to lower the production cost, such as the sequential production of ethanol and PAC [ 22 ].…”

Design of an ionic liquid as a solvent for the extraction of a pharmaceutical intermediate

“…Using these basic groups, ILs with alkyl, allyl, hydroxyl and keto groups and combinations of these groups as side chains may be designed. It is to be noted that the IL, [MIM][PF 6 ], is available as one of the main UNIFAC groups in Lei et al [23], using which [BMIM][PF 6 ] can be designed (which has been experimentally proven to successfully extract R-PAC from an aqueous broth [4]). However, due to the unavailability of the UNIFAC binary interaction parameters of this IL with water, [MIM][PF 6 ] has not been considered for the design here.…”

“…Current industrial practice employs toluene as the solvent to extract R-PAC. Recently, experiments have been performed where an ionic liquid (IL), [BMIM][PF 6 ], has been employed to extract R-PAC from an aqueous broth successfully [4]. This is the motivation for the work reported in this article, where we aim to develop a computational approach for shortlisting potential ILs which may replace toluene in the extraction of R-PAC.…”