title: Ultrasound-accelerated enzymatic synthesis of sugar esters in nonaqueous solvents.
abstract: Comparative studies of enzymatic synthesis of glucose esters under ultrasound and shaking were carried out in nonaqueous media. The influence of solvents, enzymes, chain length of the acyl donors, the power of the ultrasound bath, and intermittent ultrasound on the enzymatic synthesis was investigated. Among the eight solvents selected, pyridine was the most appropriate with alkaline protease from Bacillus subtilis whether under ultrasound or shaking. The acceleration effect of ultrasound with Novozym 435 and the alkaline protease from B. subtilis-catalyzed transesterification increased with the chain length of acyl donors, decreasing from C(10) to C(4). We also investigated the influence of the power (50, 100, and 120 W) of the ultrasound irradiation and the manner of operation (continuous ultrasound, 10 min ultrasound/20 min shaking without ultrasound) on the transesterification. The results showed that higher power and continual operational gave the better acceleration. Ultrasound did not change the character and selectivity of the enzyme in the transesterification.
authors.affiliation: Department of Chemistry, Zhejiang University, Hangzhou, People's Republic of China.
authors.forename: Yong-mei
authors.initials: YM
authors.lastname: Xiao
authors.forename: Qi
authors.initials: Q
authors.lastname: Wu
authors.forename: Ying
authors.initials: Y
authors.lastname: Cai
authors.forename: Xian-fu
authors.initials: XF
authors.lastname: Lin
mesh_terms: D001412:Bacillus subtilis / Q000201:enzymology; D001426:Bacterial Proteins / Q000378:metabolism*; D010450:Endopeptidases / Q000378:metabolism*; D004800:Enzymes, Immobilized; D004951:Esterification; D004952:Esters / Q000138:chemical synthesis*; D005656:Fungal Proteins; D005947:Glucose / Q000031:analogs & derivatives* / Q000138:chemical synthesis*; D008049:Lipase / Q000378:metabolism; D012997:Solvents; D014465:Ultrasonics; D014753:Vinyl Compounds / Q000737:chemistry
chemical_list: D001426:Bacterial Proteins; D004800:Enzymes, Immobilized; D004952:Esters; D005656:Fungal Proteins; D012997:Solvents; D014753:Vinyl Compounds; C093667:Novozyme 435; D008049:Lipase; D010450:Endopeptidases; C087822:alkaline protease; D005947:Glucose