• Home
  • Search Results
  • Synthesis of fatty acid sterol esters using cholesterol esterase from Trichoderma sp. AS59.

Synthesis of fatty acid sterol esters using cholesterol esterase from Trichoderma sp. AS59.

Enzyme and microbial technology (2011-11-25)
Naoya Morinaga, Atsushi Maeda, Takayuki Mizuno, Masanori Bunya, Shigeo Sugihara, Akio Sugihara
ABSTRACT

We recently reported the characterization of novel cholesterol esterase (EC. 3.1.1.13) from Trichoderma sp. and preliminary work on sterol ester synthesis. In the present study, we further examined the enzyme ability to synthesize cholesterol esters from cholesterol and free fatty acids of various chain lengths, and compared the fatty acid specificity in synthesis with that in hydrolysis. The enzyme catalyzed the synthesis of medium- and long-chain fatty acid cholesterol esters, but failed to synthesize short-chain fatty acid esters. The fatty acid specificities in the synthesis and hydrolysis of cholesterol esters were entirely different from each other. Unlike other lipolytic enzymes, the enzyme was largely independent of water content in the synthesis of cholesterol oleate, and it achieved near-complete esterification in the presence of an equimolar excess of oleic acid. Of additional interest is the finding that the addition of n-hexane markedly enhanced the esterification activities on all the medium- and long-chain saturated fatty acids used. Based on these findings, we attempted to synthesize stigmasterol stearate as a food additive to lower cholesterol levels in blood plasma, and found that the enzyme catalyzed effective synthesis of the ester without the need of dehydration during the reaction, indicating the potential utility of the enzyme in the food industry.

MATERIALS
Product Number
Brand
Product Description

Sigma-Aldrich
Glyceryl trioleate, ≥99%
Sigma-Aldrich
Methyl oleate, 99%
Supelco
Methyl oleate, analytical standard
Sigma-Aldrich
Methyl oleate, technical grade, 70%
Sigma-Aldrich
Glyceryl trioleate, ≥97.0% (TLC)
Sigma-Aldrich
Glyceryl trioleate, ~65%
Sigma-Aldrich
Methyl elaidate, ≥99% (capillary GC)
Supelco
cis-9-Octadecenoic acid methyl ester, certified reference material, 10 mg/mL in heptane
Supelco
Methyl elaidate, analytical standard