Lipase-catalyzed synthesis of two new antioxidants: 4-- and 3--palmitoyl chlorogenic acids

International audienceChlorogenic acid (5-caffeoyl quinic acid (CQA)) extracted from (44%, w/w) with 98% purity, was acylated with palmitic acid by Novozym 435 to yield mono-acylated CQA. Acylation of CQA was achieved in 2-methyl-2-butanol at 60°C, and yielded two mono-acylated products: a major product acylated at the -4 of the quinic moiety (4--palmitoyl chlorogenic acid) and a minor product acylated at the -3 (3--palmitoyl chlorogenic acid). The bioconversions obtained in 7 days ranged from 14 to 60% and were influenced by the molar ratio of palmitic acid/CQA, which ranged from 10 to 80. The regioselectivity (4--palmitoyl/3--palmitoyl ratio) of the reaction was also affected by the molar ratio, and ranged from 90 to 70%. The scavenging activities against 1,1-diphenyl-2-picryl-hydrazyl radicals demonstrated that these palmitoyl CQA derivatives are associated with antioxidant activity (70% vs CQA)

A Continuous and Sensitive Spectrophotometric Assay for Lipase and Phospholipase A Activities using α-Eleostearic Acid-containing Substrates

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