Kinetic study of 2-butanol O-acylation and sec-butylamine N-acylation catalyzed by Candida antarctica lipase B

• Main Authors: Le Joubioux, Florian, Oussama, A., Bridiau, Nicolas, Graber, Marianne, Maugard, Thierry
• Other Authors: LIttoral ENvironnement et Sociétés (LIENSs), La Rochelle Université (ULR)-Centre National de la Recherche Scientifique (CNRS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2011
• Subjects: [SDV.BIO]Life Sciences [q-bio]/Biotechnology; [INFO.INFO-BT]Computer Science [cs]/Biotechnology; Antarc*; Antarctica
• Online Access: https://hal.science/hal-00790682; https://hal.science/hal-00790682/document; https://hal.science/hal-00790682/file/publi1_florian_HAL.pdf

International audience The aim of this work was to study the differential behavior shown by Candida antarctica lipase B during the O-acylation and N-acylation of monofunctional alcohols and monofunctional amines. To achieve this, 2-butanol and sec-butylamine were used as model molecules. Yields, kinetics and enantioselectivity were studied for both reactions. Although a steady-state ordered ternary complex bi-bi mechanism was obtained for the O-acylation of 2- butanol, a ping-pong bi-bi mechanism was obtained for the N-acylation in case of low sec- butylamine concentrations. The values of apparent kinetics parameters were calculated: the enantiomeric ratios (E) were evaluated and confirmed the preference of Candida antarctica lipase B for the (R)-enantiomer, which was consistent with the literature. The nantioselectivity was calculated for the alcohol (E ≈ 3.17) and for the amine (E ≈ 1.34). Concerning the O-acylation, the yields were found to be very similar for both enantiomers R and S. However, both initial rates and yields of the (R)-enantiomer N-acylation were higher than those of the (S)-enantiomer. In the last part of our study, the chemoselectivity of Candida antarctica lipase B was evaluated, showing that Candida antarctica lipase B was a chemoselective enzyme that preferentially catalyzed the O-acylation to the detriment of the N-acylation (C ≈ 92, for the selective acylation of (R)-enantiomers). These results provide new insights for the synthesis of products issued from the selective acylation of multifunctional substrates such as amino-alcohols.