Lipozyme TL IM as Catalyst for the Synthesis of Eugenyl Acetate in Solvent-Free Acetylation

Abstract

The ability of commercial immobilized lipase from Thermomyces lanuginosus (Lipozyme TL IM) to catalyze the acetylation of essential clove oil with acetic anhydride in a solvent-free system was studied, and the antimicrobial activity of the ester formed was evaluated as well. Experimental design based on two variables (eugenol to acetic anhydride molar ratio and temperature) was employed to evaluate the experimental conditions of eugenyl acetate ester production. The maximum conversion yield (92.86 %) was obtained using Lipozyme TL IM (5 wt%, based on the total amount of substrates), with eugenol to acetic anhydride molar ratio of 1:5 at 70 °C. The chemical structure of the eugenyl acetate ester obtained at the optimized condition, and purified, was confirmed by the proton nuclear magnetic resonance ((1)H-NMR) analysis. The antimicrobial activity of eugenyl acetate ester was proven effective on Gram-positive and Gram-negative bacteria, with means of 16.62 and 17.55 mm of inhibition halo.

Continuous production of eugenol esters using enzymatic packed‐bed microreactors and an evaluation of the products as antifungal agents

“…Having demonstrated that the unprecedented synthesis of eugenyl isobutyrate can be efficiently achieved in continuous‐flow mode with the aid of Novozym 435 or Lipozyme RM IM packed‐bed microreactors, we also verified the efficiency of the same experimental set‐up for eugenyl acetate synthesis. We were encouraged in doing this by previous works that described the enzymatic synthesis of eugenyl acetate under batch and continuous‐flow mode in solvent‐free systems with experimental conditions (substrate molar ratio and temperature) very similar to those determined in this work . Thus, we conducted the tests to assess the operational stability of both the Novozym 435 and Lipozyme RM IM microreactors using an eugenol/acetic anhydride molar ratio of 1 : 5, a feed flow rate of 8 μL min −1 , and a temperature of 68 °C.…”

“…We were encouraged in doing this by previous works that described the enzymatic synthesis of eugenyl acetate under batch and continuous-flow mode in solventfree systems with experimental conditions (substrate molar ratio and temperature) very similar to those determined in this work. [11][12][13]15 Thus, we conducted the tests to assess the operational stability of both the Novozym 435 and Lipozyme RM IM microreactors using an eugenol/acetic anhydride molar ratio of 1 : 5, a feed flow rate of 8 μL min −1 , and a temperature of 68 °C. Figure 5 Most of the experimental works on esterification synthesis have shown that acetates have no kind of inhibition on lipases, no matter the type of lipase.…”

“…The eugenol esters have been mainly produced through traditional esterification reactions, with acyl chlorides as acylating agents, although several enzymatic syntheses have been proposed as alternative processes. The lipase‐catalysed eugenol esterification reactions are usually carried out in solvent organic media or under solvent‐free conditions . The (2‐methoxy‐4‐prop‐2‐enylphenyl) acetate (eugenyl acetate) showed increased stability with respect to eugenol, preserving its potential as an antifungal, antimicrobial, and antileishmanial therapeutic agent .…”

“…The lipase-catalysed eugenol esterification reactions are usually carried out in solvent organic media or under solvent-free conditions. [11][12][13] The (2-methoxy-4-prop-2-enylphenyl) acetate (eugenyl acetate) showed increased stability with respect to eugenol, preserving its potential as an antifungal, antimicrobial, and antileishmanial therapeutic agent. 11,[14][15][16] In addition, it has also been proposed as an eco-friendly larvicidal compound against larvae of Aedes aegypti, with lower toxicity and increased activity with respect to eugenol.…”

Encapsulation of eugenyl acetate in PHBV using SEDS technique and in vitro release evaluation

“…Eugenyl acetate is an ester that can be used as antimicrobial agent (Silva et al 2015;Chiaradia et al 2012), anticancerous (Carrasco et al 2008), acaricide (Pasay et al 2010), growth inhibitor of Aedes aegypti mosquito that transmits dengue (Pandey et al 2013), prevent teeth decalcification (Marya et al 2012) and may be employed as additive in biofuels (Kadarohman et al 2012). Besides, eugenyl acetate forms part of the European Union database and is authorized for use in food.…”