Optimized Enzymatic Synthesis of Hesperidin Fatty Acid Esters in a Two-Phase System Containing Ionic Liquid

Abstract

Response surface methodology (RSM) based on a five-level, three-variable central composite design (CCD) was employed for modeling and optimizing the conversion yield of the enzymatic acylation of hesperidin with decanoic acid using immobilized Candida antarctica lipase B (CALB) in a two-phase system containing[bmim]BF4. The three variables studied (molar ratio of hesperidin to decanoic acid, [bmim]BF4/acetone ratio and lipase concentration) significantly affected the conversion yield of acylated hesperidin derivative. Verification experiments confirmed the validity of the predicted model. The lipase showed higher conversion degree in a two-phase system using [bmim]BF4 and acetone compared to that in pure acetone. Under the optimal reaction conditions carried out in a single-step biocatalytic process when the water content was kept lower than 200 ppm, the maximum acylation yield was 53.6%.

Biocatalytic Synthesis of Flavonoid Esters by Lipases and Their Biological Benefits

“…Our research group reported that, for the acylation of hesperidin with decanoic acid catalyzed by CALB, when the water content of the reaction medium increased from < 200 ppm to higher than 550 ppm, the conversion rate decreased from 39.7 to 14.0 % (▶ Fig. 6) [32].…”

“…Our study research group recently reported the optimization of this process by Response Surface Methodology. The conversion rate of hesperidin to its ester (hesperidin decanoate) in the optimized conditions was 55.0 % [32].…”

“…Generally, molar ratios from 5 : 1 to 15 : 1 (acyl donor/flavonoid) have been studied. Many authors reported that 5 : 1 is the most efficient ratio for flavonoid acylation reactions [7,13,69,70], but other ratios have also been reported such as 7 : 1 [32] and 15 : 1 [6]. This fact may be attributed to interactions between the acyl donor/flavonoid molar ratio and other factors that influence the acylation reaction.…”

“…This fact may be attributed to interactions between the acyl donor/flavonoid molar ratio and other factors that influence the acylation reaction. In fact, when studying the optimization of the enzymatic acylation of hesperidin with decanoic acid via Response Surface Methodology, our research group found that there was a significant interaction (p < 0.1) between the acyl donor/flavonoid molar ratio and the composition of the reaction medium ([bmim]BF 4 /acetone ratio, v/v) [32].…”

“…▶Fig. 6Reaction progress of the enzymatic acylation of hesperidin (100 mM) with decanoic acid (500 mM) catalyzed by immobilized CALB (8.0 mg/mL) in [bmim]BF 4 and acetone (5 : 5, v/v) at 50°C[32].…”