Caffeic Acid Decyl Ester: An Antioxidant Principle from Phleum pratense

Evaluation of antibacterial, antioxidant and DNA protective capacity of Chenopodium album's ethanolic leaf extract

We have investigated the antibacterial effects of Chenopodium album's ethanolic leaf extract (CAE) on all the Gram (+) and Gram (-) microorganisms and evaluated the protective effects of CAE on both yeast and human mononuclear leukocytes' genomic DNA upon oxidative shock. Antibacterial activity was recorded on Bacillus subtilis with 13 mm of inhibition zone. Total oxidative status (TOS) and the total antioxidative status (TAS) levels were determined to evaluate the antioxidant activity of CAE. Results indicated that there was a good correlation between dose of CAE and TAS levels. We also observed that CAE protect the DNA of both yeast and mononuclear leukocytes against the damaging effect of hydrogen peroxide. The comet assay, applied on both Saccharomyces cerevisiae BY4741 (MATa his3Δ1 leu2Δ0 met15Δ0 ura3Δ0) and human leukocytes, results suggested that there was statistically significant correlation between CAE dilutions and antigenotoxic activity.

Highly efficient preparation of lipophilic hydroxycinnamates by solvent-free lipase-catalyzed transesterification

Various medium- or long-chain alkyl cinnamates and hydroxycinnamates, including oleyl p-coumarate as well as palmityl and oleyl ferulates, were prepared in high yield by lipase-catalyzed transesterification of an equimolar mixture of a short-chain alkyl cinnamate and a fatty alcohol such as lauryl, palmityl, and oleyl alcohol under partial vacuum at moderate temperature in the absence of solvents and drying agents in direct contact with the reaction mixture. Immobilized lipase B from Candida antarctica was the most effective biocatalyst for the various transesterification reactions. Transesterification activity of this enzyme was up to 56-fold higher than esterification activity for the preparation of medium- and long-chain alkyl ferulates. The relative transesterification activities found for C. antarctica lipase were of the following order: hydrocinnamate > cinnamate > 4-hydroxyhydrocinnamate > 3-methoxycinnamate > 2-methoxycinnamate approximately 4-methoxycinnamate approximately 3-hydroxycinnamate > hydrocaffeate approximately 4-hydroxycinnamate > ferulate > 2-hydroxycinnamate > caffeate approximately sinapate. With respect to the position of the hydroxy substituents at the phenyl moiety, the transesterification activity of C. antarctica lipase B increased in the order meta > para > ortho. The immobilized lipases from Rhizomucor miehei and Thermomyces lanuginosus demonstrated moderate and low transesterification activity, respectively. Compounds with inverse chemical structure, that is, 3-phenylpropyl alkanoates such as 3-(4-hydroxyphenyl)propyl oleate and 3-(3,4-dimethoxyphenyl)propyl oleate, were obtained by C. antarctica lipase-catalyzed transesterification of fatty acid methyl esters with the corresponding 3-phenylpropan-1-ols in high yield, as well.

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.