Solvent-free lipase-catalyzed preparation of long-chain alkyl phenylpropanoates and phenylpropyl alkanoates.
An enzymatic method was developed for the preparation of medium- or long-chain alkyl 3-phenylpropenoates (alkyl cinnamates), particularly alkyl hydroxy- and methoxy-substituted cinnamates such as oleyl p-coumarate and oleyl ferulate. The various alkyl cinnamates were formed in high to moderate yield by lipase-catalyzed esterification of cinnamic acid and its analogues with fatty alcohols in vacuo at moderate temperatures in the absence of drying agents and solvents. Immobilized Candida antarctica lipase B was the most effective biocatalyst for the various esterification reactions. The relative esterification activities were of the following order: dihydrocinnamic > cinnamic > 3-methoxycinnamic > dihydrocaffeic approximately 3-hydroxycinnamic > 4-methoxycinnamic > 2-methoxycinnamic > 4-hydroxycinnamic > ferulic approximately 3,4-dimethoxycinnamic > 2-hydroxycinnamic acid. With respect to the position of the substituents at the phenyl moiety, the esterification activity increased in the order meta > para > ortho. Rhizomucor miehei lipase demonstrated moderate esterification activity. Compounds with inverse chemical structure, that is, 3-phenylpropyl alkanoates such as 3-(4-hydroxyphenyl)propyl oleate, were also obtained in high yield by esterification of fatty acids with the corresponding 3-phenylpropan-1-ols.
Vosmann
Klaus
K
Institut für Lipidforschung, Bundesforschungsanstalt für Ernährung und Lebensmittel, Piusallee 68-76, D-48147 Münster, Germany.
Weitkamp
Petra
P
Weber
Nikolaus
N
D000478:Alkylation; D002934:Cinnamates / Q000378:metabolism*; D004800:Enzymes, Immobilized / Q000378:metabolism; D004951:Esterification; D005656:Fungal Proteins; D008049:Lipase / Q000378:metabolism*; D012997:Solvents; D013379:Substrate Specificity
D002934:Cinnamates; D004800:Enzymes, Immobilized; D005656:Fungal Proteins; D012997:Solvents; C029010:cinnamic acid; D008049:Lipase; C431349:lipase B, Candida antarctica