Tailoring the Spacer Arm for Covalent Immobilization of Candida antarctica Lipase B-Thermal Stabilization by Bisepoxide-Activated Aminoalkyl Resins in Continuous-Flow Reactors.
An efficient and easy-to-perform method was developed for immobilization of CaLB on mesoporous aminoalkyl polymer supports by bisepoxide activation. Polyacrylate resins (100-300 µm; ~50 nm pores) with different aminoalkyl functional groups (ethylamine: EA and hexylamine: HA) were modified with bisepoxides differing in the length, rigidity and hydrophobicity of the units linking the two epoxy functions. After immobilization, the different CaLB preparations were evaluated using the lipase-catalyzed kinetic resolution (KR) of racemic 1-phenylethanol (rac-1) in batch mode and in a continuous-flow reactor as well. Catalytic activity, enantiomer selectivity, recyclability, and the mechanical and long-term stability of CaLB immobilized on the various supports were tested. The most active CaLB preparation (on HA-resin activated with 1,6-hexanediol diglycidyl ether-HDGE) retained 90% of its initial activity after 13 consecutive reaction cycles or after 12 month of storage at 4 °C. The specific rate (rflow), enantiomer selectivity (E) and enantiomeric excess (ee) achievable with the best immobilized CaLB preparations were studied as a function of temperature in kinetic resolution of rac-1 performed in continuous-flow packed-bed bioreactors. The optimum temperature of the most active HA-HDGE CaLB in continuous-flow mode was 60 °C. Although CaLB immobilized on the glycerol diglycidyl ether (GDGE)-activated EA-resin was less active and less selective, a much higher optimum temperature (80 °C) was observed with this form in continuous-flow mode KR of rac-1.
Department of Organic Chemistry and Technology, Budapest University of Technology and Economics, M&#369;egyetem rkp. 3, Budapest H-1111, Hungary. abahazi.emese@mail.bme.hu.
Emese
E
Abaházi
Department of Organic Chemistry and Technology, Budapest University of Technology and Economics, M&#369;egyetem rkp. 3, Budapest H-1111, Hungary. ldavka@gmail.com.
Dávid
D
Lestál
SynBiocat LLC; L&#246;v&#337;h&#225;z u. 19/1, Budapest H-1043, Hungary. zoltan.boros@synbiocat.com.
Zoltán
Z
Boros
Department of Organic Chemistry and Technology, Budapest University of Technology and Economics, M&#369;egyetem rkp. 3, Budapest H-1111, Hungary. poppe@mail.bme.hu.|SynBiocat LLC; L&#246;v&#337;h&#225;z u. 19/1, Budapest H-1043, Hungary. poppe@mail.bme.hu.
László
L
Poppe
D000588:Amines / Q000737:chemistry; D001592:Benzyl Alcohols / Q000737:chemistry; D019149:Bioreactors; D002175:Candida / Q000201:enzymology; D002384:Catalysis; D004795:Enzyme Stability; D004800:Enzymes, Immobilized / Q000737:chemistry* / Q000378:metabolism; D004852:Epoxy Compounds / Q000737:chemistry; D005021:Ethylamines / Q000737:chemistry; D005656:Fungal Proteins / Q000737:chemistry* / Q000378:metabolism; D008049:Lipase / Q000737:chemistry* / Q000378:metabolism; D013237:Stereoisomerism; D013696:Temperature
D000588:Amines; D001592:Benzyl Alcohols; D004800:Enzymes, Immobilized; D004852:Epoxy Compounds; D005021:Ethylamines; D005656:Fungal Proteins; C007940:hexylamine; C002017:methylphenyl carbinol; D008049:Lipase; C431349:lipase B, Candida antarctica; C041564:ethylamine
continuous-flow reactor; covalent attachment; immobilization; kinetic resolution; lipase; thermal stabilization