Brady, DReddy, SMboniswa, BSteenkamp, Lucia HRousseau, AParkinson, CJChaplin, JMitra, RKMoutlana, TMarais, SFGardiner, NS2012-03-132012-03-132012-03Brady, D, Reddy, S, Mboniswa, B, Steenkamp, L.H, Rousseau, A, Parkinson, CJ, Chaplin, J, Mitra, RK, Moutlana, T, Marais, SF and Gardiner, NS. 2012. Biocatalytic enantiomeric resolution of l-menthol from an eight isomeric menthol mixture. Journal of Molecular Catalysis B, vol. 75, pp 1-101381-1177http://www.sciencedirect.com/science/article/pii/S1381117711002797http://hdl.handle.net/10204/5641Copyright: 2012 Elsevier. This is the post-print version of the work. The definitive version is published in Journal of Molecular Catalysis B, vol. 75, pp 1-10. The title of the final version was modified.The four diastereomers of menthol and their enantiomers, namely dl-menthol, dl-neomenthol, dl-neoisomenthol and dl isomenthol, were synthesised by the hydrogenation of thymol to yield an eight isomer liquid menthol. A suitably selective lipase was sought to preferentially esterify l-menthol in hexane, hence simplifying separation from this diasteromeric mix through distillation. From an initial screen of over 70 enzyme preparations, a commercial Pseudomonas fluorescens lipase (Amano AK) was selected, and vinyl acetate was chosen as a suitable irreversible acyl donor for transesterification. The enzyme was recycled a total of 150 times in 5 ml batch reactions using liquid menthol and achieving an overall yield of 184.31 g dl-menthol/g enzyme. An enantiomeric excess of l-menthol of greater than 95% was reproducibly achievable at a conversion of 30% dl-menthol (0.68 M) at =50°C. On the basis of the composition of liquid menthol the reaction had a diastereomeric ratio of 81%. The resolution reaction was scaled up 400 fold to 2 L and the ezyme recycled 38 times with an average conversion of the available l-menthol of 59%.enTransesterificationLipasesBSTRPseudomonas fluorescensDiasteromericEnantiomeric resolutionArticleBrady, D., Reddy, S., Mboniswa, B., Steenkamp, L. H., Rousseau, A., Parkinson, C., ... Gardiner, N. (2012). Biocatalytic enantiomeric resolution of l-menthol from an eight isomeric menthol mixture. http://hdl.handle.net/10204/5641Brady, D, S Reddy, B Mboniswa, Lucia H Steenkamp, A Rousseau, CJ Parkinson, J Chaplin, et al "Biocatalytic enantiomeric resolution of l-menthol from an eight isomeric menthol mixture." (2012) http://hdl.handle.net/10204/5641Brady D, Reddy S, Mboniswa B, Steenkamp LH, Rousseau A, Parkinson C, et al. Biocatalytic enantiomeric resolution of l-menthol from an eight isomeric menthol mixture. 2012; http://hdl.handle.net/10204/5641.TY - Article AU - Brady, D AU - Reddy, S AU - Mboniswa, B AU - Steenkamp, Lucia H AU - Rousseau, A AU - Parkinson, CJ AU - Chaplin, J AU - Mitra, RK AU - Moutlana, T AU - Marais, SF AU - Gardiner, NS AB - The four diastereomers of menthol and their enantiomers, namely dl-menthol, dl-neomenthol, dl-neoisomenthol and dl isomenthol, were synthesised by the hydrogenation of thymol to yield an eight isomer liquid menthol. A suitably selective lipase was sought to preferentially esterify l-menthol in hexane, hence simplifying separation from this diasteromeric mix through distillation. From an initial screen of over 70 enzyme preparations, a commercial Pseudomonas fluorescens lipase (Amano AK) was selected, and vinyl acetate was chosen as a suitable irreversible acyl donor for transesterification. The enzyme was recycled a total of 150 times in 5 ml batch reactions using liquid menthol and achieving an overall yield of 184.31 g dl-menthol/g enzyme. An enantiomeric excess of l-menthol of greater than 95% was reproducibly achievable at a conversion of 30% dl-menthol (0.68 M) at =50°C. On the basis of the composition of liquid menthol the reaction had a diastereomeric ratio of 81%. The resolution reaction was scaled up 400 fold to 2 L and the ezyme recycled 38 times with an average conversion of the available l-menthol of 59%. DA - 2012-03 DB - ResearchSpace DP - CSIR KW - Transesterification KW - Lipases KW - BSTR KW - Pseudomonas fluorescens KW - Diasteromeric KW - Enantiomeric resolution LK - https://researchspace.csir.co.za PY - 2012 SM - 1381-1177 T1 - Biocatalytic enantiomeric resolution of l-menthol from an eight isomeric menthol mixture TI - Biocatalytic enantiomeric resolution of l-menthol from an eight isomeric menthol mixture UR - http://hdl.handle.net/10204/5641 ER -