title: Biocatalytic synthesis of δ-gluconolactone and ε-caprolactone copolymers.
abstract: The biodegradability and biocompatibility properties of ε-caprolactone homopolymers place it as a valuable raw material, particularly for controlled drug delivery and tissue engineering applications. However, the usefulness of such materials is limited by their low hydrophilicity and slow biodegradation rate. In order to improve polycaprolactone properties and functionalities, copolymerization of ε-caprolactone with δ-gluconolactone was investigated. Since enzymatic reactions involving sugars are usually hindered by the low solubility of these compounds in common organic solvents, finding the best reaction medium was a major objective of this research. The optimal copolymerization conditions were set up by using different organic media (solvent and solvents mixtures), as well as solvent free systems that are able to dissolve (completely or partially) sugars, and are nontoxic for enzymes. Native and immobilized lipases by different immobilization techniques from Candida antarctica B and Thermomyces lanuginosus have been used as biocatalyst at 80°C. Although the main copolymer amount was synthesized in DMSO:t-BuOH (20:80) medium, the highest polymerization degrees, up to 16 for the copolymer product, were achieved in solventless conditions. The products, cyclic and linear polyesters, have been characterized by FT-IR and MALDI-TOF MS analysis. The reaction product analysis revealed the formation of cyclic products that could be the major impediment of further increase of the chain length.
authors.affiliation: Faculty of Industrial Chemistry and Environmental Engineering, University "Politehnica" of Timisoara, Timisoara, Romania.
authors.forename: Anamaria
authors.initials: A
authors.lastname: Todea
authors.affiliation: Faculty of Industrial Chemistry and Environmental Engineering, University "Politehnica" of Timisoara, Timisoara, Romania.
authors.forename: Valentin
authors.initials: V
authors.lastname: Badea
authors.affiliation: Department of Applied Chemistry, University of Debrecen, Debrecen, Hungary.
authors.forename: Lajos
authors.initials: L
authors.lastname: Nagy
authors.forename: Sándor
authors.initials: S
authors.lastname: Kéki
authors.affiliation: Wageningen UR Food & Biobased Research, Wageningen, The Netherlands.
authors.forename: Carmen G
authors.initials: CG
authors.lastname: Boeriu
authors.affiliation: Faculty of Industrial Chemistry and Environmental Engineering, University "Politehnica" of Timisoara, Timisoara, Romania.
authors.forename: Francisc
authors.initials: F
authors.lastname: Péter
mesh_terms: D055162:Biocatalysis; D002175:Candida / Q000737:chemistry / Q000201:enzymology; D002208:Caproates / Q000737:chemistry*; D004800:Enzymes, Immobilized; D005656:Fungal Proteins / Q000737:chemistry* / Q000302:isolation & purification; D005942:Gluconates / Q000737:chemistry*; D006358:Hot Temperature; D007783:Lactones / Q000737:chemistry*; D008049:Lipase / Q000737:chemistry* / Q000302:isolation & purification; D011091:Polyesters / Q000138:chemical synthesis*; D058105:Polymerization; D004718:Saccharomycetales / Q000737:chemistry / Q000201:enzymology; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D002208:Caproates; D004800:Enzymes, Immobilized; D005656:Fungal Proteins; D005942:Gluconates; D007783:Lactones; D011091:Polyesters; C121056:caprolactone; D008049:Lipase; C431349:lipase B, Candida antarctica; C010730:beta-glucono-1,5-lactone