Enzymatic selective synthesis of 1,3-DAG based on deep eutectic solvent acting as substrate and solvent

Area of Science:

• Biocatalysis
• Green Chemistry
• Organic Synthesis

Background:

• Enzymatic esterification is a key process in synthesizing various esters.
• Deep eutectic solvents (DES) offer tunable properties as reaction media and substrates.
• Glycerol esterification with fatty acids is important for producing emulsifiers and specialty chemicals.

Purpose of the Study:

• To investigate the enzymatic selective esterification of oleic acid with glycerol using DES.
• To explore the influence of choline chloride (ChCl) and betaine on lipase activity and selectivity.
• To optimize the synthesis of diacylglycerols (DAGs), especially 1,3-DAG.

Main Methods:

• Lipase-catalyzed esterification of oleic acid and glycerol in the presence of ChCl or betaine.
• Systematic investigation of factors influencing esterification, including water content.
• Analysis of glyceride composition and enzyme selectivity.

Main Results:

• Betaine showed moderate effects on lipase compared to ChCl.
• Water content significantly influenced esterification and enzyme selectivity.
• ChCl addition altered glyceride composition, leading to optimal accumulation of DAG, particularly 1,3-DAG, due to eutectic effects.
• A model system yielded 42.9 mol% 1,3-DAG within 1 hour using ChCl and Novozym 435.

Conclusions:

• Deep eutectic solvents, specifically ChCl, can significantly enhance enzymatic synthesis of DAGs from glycerol and oleic acid.
• The eutectic effect of ChCl promotes the selective formation of 1,3-DAG.
• This approach offers an efficient method for producing valuable DAG isomers.