Esterification of ferulic acid with polyols using a ferulic acid esterase from Aspergillus niger

• Published in: Biochimica et biophysica acta Vol. 1760; no. 7; pp. 1071 - 1079
• Main Authors: Tsuchiyama, Moriyasu, Sakamoto, Tatsuji, Fujita, Tomoyuki, Murata, Shuichi, Kawasaki, Haruhiko
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.07.2006
• Subjects: Antioxidants - chemistry; Aspergillus niger; Aspergillus niger - enzymology; Biphenyl Compounds - chemistry; Catalysis; Coumaric Acids - chemistry; Esterases - chemistry; Esterification; Ferulic acid esterase; Free Radicals; Glycerol - chemistry; Glyceryl ferulate; Hydrazines - chemistry; Hydrogen-Ion Concentration; Hydrolysis; Magnetic Resonance Spectroscopy; Models, Chemical; Monoglycerides - chemistry; Picrates; Polymers - chemistry; Protein Structure, Tertiary; Substrate Specificity; Temperature; Transesterification; Ferulic acid esterase; Glyceryl ferulate; Transesterification; Aspergillus niger; Esterification
• ISSN: 0304-4165; 0006-3002; 1872-8006
• DOI: 10.1016/j.bbagen.2006.03.022

Commercially available enzyme preparations were screened for enzymes that have a high ability to catalyze direct ester-synthesis of ferulic acid with glycerol. Only a preparation, Pectinase PL “Amano” produced by Aspergillus niger, feruloylated glycerol under the experimental conditions. The enzyme responsible for the esterification was purified and characterized. This enzyme, called FAE-PL, was found to be quite similar to an A. niger ferulic acid esterase (FAE-III) in terms of molecular mass, pH and temperature optima, substrate specificity on synthetic substrates, and the N-terminal amino acid sequence. FAE-PL highly catalyzed direct esterification of ferulic acid and sinapinic acid with glycerol. FAE-PL could feruloylate monomeric sugars including arabinose, fructose, galactose, glucose, and xylose. We determined the suitable conditions for direct esterification of ferulic acid with glycerol to be as follows: 1% ferulic acid in the presence of 85% glycerol and 5% dimethyl sulfoxide at pH 4.0 and 50 °C. Under these conditions, 81% of ferulic acid could be converted to 1-glyceryl ferulate, which was identified by 1H-NMR. The ability of 1-glyceryl ferulate to scavenge 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals was higher than that of the anti-oxidant butyl hydroxytoluene.