Mild, Solvent-Free ω-Hydroxy Acid Polycondensations Catalyzed by Candida antarctica Lipase B

Abstract

Immobilized Candida antarctica Lipase B (Novozyme-435) was studied for bulk polyesterifications of linear aliphatic hydroxyacids of variable chain length. The products formed were not fractionated by precipitation. The relative reactivity of the hydroxyacids was l6-hydroxyhexadecanoic acid approximately 12-hydroxydodecanoic acid approximately 10-hydroxydecanoic acid (DPavg congruent with 120, Mw/Mn <or = 1.5, 48 h, 90 degrees C) > 6-hydroxyhexanoic acid (DPavg congruent with 80, Mw/Mn < or = 1.5, 48 h, 90 degrees C). Remarkable improvements in molecular-weight buildup resulted from leaving water in the reaction. By 4 h, without application of vacuum, the DPavg for 12- and 16-carbon hydroxyacids was about 90. In contrast, with identical substrates and water removal, the DPavg at 4 h was about 23. Large differences in the molecular-weight build up of 12-hydroxydodecanoic acid were observed for catalyst concentrations (%-by-wt relative to monomer) of 0.1, 0.5, 1, and 10. Nevertheless, by 24 h, with 1% catalyst containing 0.1% lipase, poly(12-hydroxydodecanoic acid) with Mn 17 600 was formed. For 12-hydroxydodecanoic acid polymerization at 90 degrees C, the catalyst activity decreased by 7, 18, and 25% at reaction times of 4, 24, and 48 h, respectively. Furthermore, the retention of catalyst activity was invariable as a function of the substrates used.

Tomato GDSL1 Is Required for Cutin Deposition in the Fruit Cuticle

“…Actually, the localization of GDSL1 in the cuticle matrix and not in the cell walls shows that the protein operates in a peculiar hydrophobic environment. It is known that lipases are active in water-depleted organic solvents (Klibanov, 2001) and can catalyze the polyesterification of hydroxy-fatty acids in such conditions (Mahapatro et al, 2004;Ebata et al, 2007). Moreover, the extent of polymerization is improved when the lipase is immobilized on an acrylic resin (Ebata et al, 2007).…”

Recent Developments in Lipase‐Catalyzed Synthesis of Polyesters

“…The DP value was beyond 100 in the polymerization of l6-hydroxyhexadecanoic acid, 12-hydroxydodecanoic acid, or 10-hydroxydecanoic acid under vacuum at a high temperature (90 8C) in bulk for 24 h, whereas the polyester with lower molecular weight was formed from 6-hydroxyhexanoic acid under similar reaction conditions. [140] This difference is probably due to the different strengths of the lipase-substrate interaction as shown in the lipasecatalyzed ring-opening polymerization of lactones in different ring size. [83] Polycondensation of methyl 6-hydroxyhexanoate, an oxyacid ester, with lipase catalyst was reported.…”

Lipase-Catalyzed Ring-Opening Copolymerization of ε-Caprolactone and β-Lactam

“…Developments in enzymatic polycondensation of 6-hydroxyhexanoic acid 23 and ROP of ε-CL 24−28 have been reported. Ringopening copolymerization of ε-CL with other lactone rings using enzymes as catalyst has been carried out previously.…”