Eco-friendly methodology for efficient synthesis and scale-up of 2-ethylhexyl-p-methoxycinnamate using Rhizopus oryzae lipase and its biological evaluation

Abstract

Lipase-mediated synthesis of phenolic acid esters is a green and economical alternative to current chemical methods. Octyl methoxycinnamate, an important UVB-absorbing compound, was synthesized by the esterification of p-methoxycinnamic acid with 2-ethyl hexanol using Rhizopus oryzae lipase. A molar ratio of 1:2 of p-methoxycinnamic acid and 2-ethyl hexanol was found to give an optimum yield using cyclo-octane (50 ml) as reaction solvent, at a temperature of 45 °C, and 750 U of lipase, resulting in a yield of 91.3 % in 96 h. This reaction was successfully scaled up to 400-ml reaction size where 88.6 %bioconversion was achieved. The synthesized compound was found to have superior antioxidant activity as compared to ascorbic acid. The synthesized compound also exhibited good antimicrobial activity against Escherichia coli, Klebsiella pneumonia, Salmonella typhi, Staphylococcus aures, Candida albicans (yeast), Aspergillus niger, Alternaria solani, and Fussarium oxysporum by well diffusion method in terms of zone of inhibitions (in mm).

Sinapic Acid Esters: Octinoxate Substitutes Combining Suitable UV Protection and Antioxidant Activity

“…For instance, p-coumaric acid, one of the major lignocellulosic-derived p-hydroxycinnamic acids [19], is subjected to methylation then esterification with 2-ethylhexanol [20,21]. It is noteworthy that the esterification can be carried out either chemically or enzymatically with lipases [22,23]. The most-described chemical pathway relies on the formation of the acyl chloride and the subsequent reaction with 2-ethylhexanol [24].…”

Green Synthesis of Ultraviolet Absorber 2-Ethylhexyl Salicylate: Experimental Design and Artificial Neural Network Modeling

“…Finally, the optimal conditions for the lipase-catalyzed synthesis of 2-ethylhexyl salicylate determined by the Neural Power software were a reaction time of 23.1 h, a reaction temperature of 66.5 • C, and an enzyme amount of 881 PLU, and an optimal conversion of 88.2% could be obtained. It has been reported that the synthesis of 2-ethylhexyl-p-methoxycinnamate by immobilized lipase at a temperature of 45 • C and an enzyme amount of 750 U resulted in a yield of 91.3% in 96 h [33]. In other literature, we found that enzyme activity might be inhibited by hydrophilic alcohols such as ethanol [34].…”

Biological Properties, Health Benefits and Enzymatic Modifications of Dietary Methoxylated Derivatives of Cinnamic Acid

“…The product of this reaction was a mixture of ferulated mono- and diacylglycerols registered under the trade name SoyScreen as an ingredient used in the manufacture of creams with a filter actively absorbing UVA/UVB radiation [ 63 ]. Lipophilic compounds with UV-absorbing ability were also obtained by enzymatic esterification reaction p -MCA with 2-ethylhexanol developed by two independent teams [ 64 , 65 ]. Biological studies also showed that the obtained ester has higher antioxidant activity than ascorbic acid and the free form of p -MCA, as well as good antimicrobial activity against a number of pathogenic microorganisms [ 65 , 66 ].…”

“…Lipophilic compounds with UV-absorbing ability were also obtained by enzymatic esterification reaction p -MCA with 2-ethylhexanol developed by two independent teams [ 64 , 65 ]. Biological studies also showed that the obtained ester has higher antioxidant activity than ascorbic acid and the free form of p -MCA, as well as good antimicrobial activity against a number of pathogenic microorganisms [ 65 , 66 ]. In 2006, also Weber’s research group reported the results of enzymatic synthesis of long-chain alkyl esters of p -methoxycinnamic acid, which can be used as lipophilic additives with antioxidant activity in food, feed and cosmetic industries [ 67 ].…”