کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
69791 | 48793 | 2013 | 6 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Kinetics and mechanism of lipase catalyzed monoacylglycerols synthesis Kinetics and mechanism of lipase catalyzed monoacylglycerols synthesis](/preview/png/69791.png)
• Monostearin was synthesized from stearic acid and (R,S)-1,2-O-iso-propylidene glycerol (solketal).
• The reaction was catalyzed by CaL B immobilized in water in oil microemulsions.
• A yield of 80% in 30 min was obtained with very low amount of biocatalyst.
• The kinetic analysis indicated that the reaction followed the ordered bi–bi mechanism with dead-end inhibition by stearic acid.
Monoacylglycerols are increasingly used in several industrial applications as effective and cheap emulsifiers. In the present work monostearin synthesis has been studied, using lipase as a biocatalyst of the esterification reaction of stearic acid with (R,S)-1,2-O-iso-propylidene glycerol (solketal). The lipase from Candida antarctica (CaL B) was immobilized in AOT/isooctane water in oil microemulsions. Optimization of the reaction conditions have shown that the highest production (80% in 30 min) could be achieved at 40 °C, in microemulsions with relatively low water content (wo = 8). Kinetic studies have shown that the esterification reaction of stearic acid with solketal catalyzed by CaL B occurs via the ordered bi–bi mechanism, in which inhibition by the acid was identified. Moreover, at high fixed solketal concentrations a negative cooperativity is pronounced, which means that binding of the alcohol lowers the affinity of the enzyme for binding of the acid. Values of all kinetic parameters have been determined.
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Journal: Journal of Molecular Catalysis B: Enzymatic - Volume 96, December 2013, Pages 34–39