Polymerization of Propyl Malolactonate in the Presence of Candida rugosa Lipase

Abstract

To gain better insight into mechanistic features of enzyme-catalyzed malolactonate polymerization, reactions with propyl malolactonate were analyzed while varying enzyme concentration, reaction media composition, and reaction temperature. Monomer conversion and product molecular weights were characterized by (1)H NMR and MALDI-TOF MS, respectively. A high extent of thermal polymerization of propyl malolactonate was observed, while the polymer chain length in all reactions was controlled by the elimination of alpha-hydrogen from propyl malolactonate with formation of a new initiator and the new chains. The most efficient enzymatic catalysis occurred in toluene (2.11 M monomer) at 60 degrees C. Candida rugosa lipase (10 wt %) accelerated polymerization 25-fold over the rate of thermal polymerization. The maximum poly(propyl malate) number-average molecular weight obtained was 5000 Da at 20 wt % enzyme with a polydispersity of 1.15. These values compare with 1800 Da and 1.5, respectively, in the absence of enzyme.

Enzymatic Synthesis of Polyesters via Ring-Opening Polymerization

“…The benzyl group was removed to quantitatively produce poly(β-malic acid) and then neutralized to obtain the water-soluble and biodegradable poly(sodium β-malate) [33,34]. The lipase-catalyzed polymerization of propyl β-malolactonate occurred in a characteristic fashion, such that the polymer chain length was controlled by the formation of double bonds due to the elimination of an α-hydrogen from the propyl β-malolactonate with the formation of a new initiator (Scheme 2e) [35].…”

“…The four-membered β-lactones with various substituents, such as α-methyl-β-propiolactone [24], β-butyrolactone (β-BL) [25][26][27][28][29], benzyl β-malolactonate [30][31][32][33][34], and propyl β-malolactonate, [35] were polymerized by lipases to yield the corresponding polyesters. Poly(3-hydroxybutanoate) (PHB) obtained from the lipasecatalyzed ring-opening polymerization of (R, S) -β-BL presented three kinds of structural isomers, i.e., cyclic PHB, linear PHB with a hydroxyl group at one end and a carboxyl group at the other end, and a linear PHB with a crotonate group at one end and a carboxyl group at the other end, were identified.…”

Nanofibrous Membranes Containing Reactive Groups: Electrospinning from Poly(acrylonitrile-co-maleic acid) for Lipase Immobilization

“…[6][7][8][9][10][11][12][13][14] As a biocatalyst, lipases have received increasing attention for biotransformation and polymer synthesis. [15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30] However, practical applications prefer immobilized enzymes because they offer easy catalyst recycling, feasible continuous operations, and simple product purification. Furthermore, immobilizing enzymes onto various insoluble or solid supports is a useful tool to increase their thermal and operational stabilities.…”

Optimization of lipase‐catalyzed polymerization of benzyl malolactonate through a design of experiment approach

“…Indeed, to the best of our knowledge, only two groups have studied the enzymatic polymerization of such lactones: Toshima et al who published results obtained on lipase-catalyzed ROP of MLABe 25,26 and one of the present authors who studied the lipase-catalyzed ROP of the propyl malolactonate. 27 However, since 2003, no work was published despites the great interest of the poly(malic acid) derivatives for the design of efficient biocompatible drug nanocarriers. 28 These polyesters are mainly obtained by chemical ROP of the MLABe or its derivatives, [28][29][30][31] or by chemical modification of naturally available PMLA.…”