Lipase mediated synthesis of rutin fatty ester: Study of its process parameters and solvent polarity

Novel enzymatic synthesis of 3-Hydroxybutyryl Naringin and its molecular identification and bioactive characterization

In this study, we synthesized 6''-O-((±)-3-hydroxybutyryl)naringin (3HBN) for the first time through enzymatic esterification of naringin with 3-hydroxybutyric acid (3HB), achieving a high conversion of 80.19 % under optimized conditions within 8 h. Structural analysis via FT-IR and 1H NMR confirmed esterification at the C-6'' hydroxyl position on the glucose moiety of naringin. Although the antioxidant capacity of 3HBN was slightly reduced compared to naringin, its enhanced lipophilicity (log P = -0.05) indicates improved bioavailability and potential for cellular absorption. Bioactivity evaluations confirmed that 3HBN exhibited stronger anti-inflammatory effects than naringin by reducing TNF-α and increasing IL-10 in LPS-stimulated immune cells. These findings suggest that 3HBN is a promising bioactive compound with potential applications across the food, cosmetic, and pharmaceutical industries, offering both enhanced stability and effective bioactivity for targeted health benefits.

Synthesis of piceid lipoate and the effect and micro-mechanism of alpha-lipoic acid moiety on its antioxidant activity

A lipophilic piceid lipoate (PIL) was synthesized by enzymatic method to enhance the antioxidant activity of piceid and improve its state in oil system. The highest substrate conversion of 93.71 % was obtained in γ-valerolactone using Novozym 435 as a catalyst, with a piceid/lipoic acid ratio of 1:15 (mM/mM), an enzyme dosage of 40 mg/mL, and 4 Å molecular sieves at 400 mg/mL. The lipophilicity and antioxidant activity of piceid and PIL were evaluated, which found the introduction of α-lipoic acid markedly increased the lipophilicity and antioxidant activity of piceid. The oxidation inhibition rate of PIL in bulk oil was nearly 2.0 and 1.9 times higher than piceid and butylated hydroxytoluene, indicating that PIL is a promising antioxidant for oil-based foods. The antioxidant micro-mechanisms of PIL were revealed by computational simulations, which found the lipoic acid moiety in PIL molecule enhanced its free radical scavenging capacity and improved its solubility, dispersion, and migration in bulk oil.

Synthesis and characterization of 3,4-dihydroxyphenyl acetic acid esters and study of their efficacy in bulk fish oil

Lipophilization of natural antioxidants is a proven strategy to enhance the solubility in bulk oil systems, thereby increasing their efficacy against oxidative degradation. This study aims to synthesize esters of 3,4-dihydroxyphenylacetic acid (3,4-DHPA) using Amberlyst-15 and to study the application of these esters in refined fish oil. Lipophilic esters were synthesized by esterification and transesterification of 3,4-DHPA in various solvent systems. Esters of methanol, butanol and hexanol were obtained with percent conversion of 81.1, 69.3 and 78.8 respectively, and were subjected to molecular characterization and in vitro oxidant assays. The 3,4-DHPA and its methyl ester showed 36% reduction in the TOTOX value over 30 days of storage. The length of the acyl chain in the ester was found to exert a high influence on its efficacy and lipophilicity. This is the first report of 3,4-DHPA and its lipophilic esters studied for enhancing the oxidative stability of fish oil.

Bioimprinted lipase-catalyzed synthesis of medium- and long-chain structured lipids rich in docosahexaenoic acid for infant formula

Medium- and long-chain structured lipids (MLSLs) rich in docosahexaenoic acid (DHA) were obtained in shorter reaction time by acidolysis of single-cell oil (DHASCO) from Schizochytrium sp. with caprylic acid (CA) using a lipase bioimprinted with fatty acids as a catalyst. The conditions for preparation of the bioimprinted lipase for the acidolysis reaction were firstly optimized and the activity of the obtained lipase was 2.17 times higher than that of the non-bioimprinted. The bioimprinted lipase was then used as a catalyst and the reaction conditions were optimized. Under the optimal conditions, the equilibrium could be achieved in 4 h, and the total and sn-1,3 CA contents in the product were 29.18% and 42.34%, respectively, and the total and sn-2 DHA contents were 46.26% and 70.12%, respectively. Such MLSLs rich in sn-1,3 CA and sn-2 DHA are beneficial for DHA absorption, and thus have potential for use in infant formula.

Improved antioxidant activity of rutin via lipase-mediated esterification with oleic acid

BACKGROUND

Oxidation is a major problem for oils and fats, which can be mitigated by antioxidants. Rutin has excellent antioxidant activity, but its poor lipid solubility greatly limits its practical application. In this study, an efficient enzymatic synthesis route of lipophilic rutin ester was established using oleic acid as an acyl donor, and the antioxidant potential of rutin oleate was evaluated for the first time by proton (¹ H) nuclear magnetic resonance (NMR) spectroscopy.

RESULTS

The synthesized product was finally identified as rutin oleate by Fourier transform infrared, high-performance liquid chromatography-mass spectrometry, and ¹ H, carbon-13, and DEPT-135 NMR analyses, and the acylation site was the 4‴-OH of the rhamnose group in the rutin molecule. The maximum conversion was over 93% after 48 h of reaction using Novozym 435 as catalyst under the best conditions among these tests. The conversion of rutin ester decreased with the increase of carbon chain length and the number of carbon-carbon double bonds of the fatty acid molecule. Most importantly, rutin oleate exhibited antioxidant capacity comparable to butylated hydroxytoluene and its counterparts (rutin and oleic acid) at low temperatures (60° C), but had a significant advantage at high temperatures (120° C).

CONCLUSION

The antioxidant activity of rutin was significantly enhanced by lipase-mediated esterification with oleic acid. Therefore, rutin oleate could be further developed as a novel antioxidant for use in oil- and fat-based foods. © 2023 Society of Chemical Industry.

Enzymatic lipophilization of bioactive compounds with high antioxidant activity: a review

Food products contain bioactive compounds such as phenolic and polyphenolic compounds and vitamins, resulting in a myriad of biological characteristics such as antimicrobial, anticarcinogenic, and antioxidant activities. However, their application is often restricted because of their relatively low solubility and stability in emulsions and oil-based products. Therefore, chemical, enzymatic, or chemoenzymatic lipophilization of these compounds can be achieved by grafting a non-polar moiety onto their polar structures. Among different methods, enzymatic modification is considered environmentally friendly and may require only minor downstream processing and purification steps. In recent years, different systems have been suggested to design the synthetic reaction of these novel products. This review presents the new trends in this area by summarizing the essential enzymatic modifications in the last decade that led to the synthesis of bioactive compounds with attractive antioxidative properties for the food industry by emphasizing on optimization of the reaction conditions to maximize the production yields. Lastly, recent developments regarding characterization, potential applications, emerging research areas, and needs are highlighted.

Probing the synergistic effects of rutin and rutin ester on the oxidative stability of sardine oil

Multicomponent antioxidant mixture is proved to be highly effective in imparting oxidative stability to the edible oil. It is believed that the high efficacy of those mixtures is due to the synergistic effect exhibited by two or more components. The current study aims to analyse the synergistic effect of a flavonoid and its corresponding ester in improving the oxidative stability of n-3 PUFA rich sardine oil. The oxidative stability of rutin, esterified rutin and their combinations at three different concentrations was studied in sardine oil stored at 37 ºC for 12 days in contact with air under darkness. The combination of rutin and rutin ester showed maximum reduction of 54.2% in oxidation at 100 mg/kg and 150 mg/kg. Perhaps this is the first report on the synergistic effect of a flavonoid and its lipophilized ester for improving the oxidative stability of n-3 PUFA rich oil.

Efficient Production of Naringin Acetate with Different Acyl Donors via Enzymatic Transesterification by Lipases

Naringin, one of the citrus flavonoids and known as a natural antioxidant, has limited bioavailability owing to its low stability and solubility. However, naringin esters formed via acylation have recently been reported to possess improved physical and chemical properties. The development of these compounds has a great potential in the food, cosmetic and pharmaceutical industries, but low conversion and productivity are barriers to industrial applications. This study aimed to improve the conversion of naringin acetate, which is formed via the enzymatic reaction between naringin and an acyl donor. An optimal reaction condition was determined by evaluating the effect of various variables (enzyme type, enzyme concentration, acyl donor, molar ratio of reactants, reaction temperature, and solvent) on the synthesis of naringin acetate. The optimal condition was as follows: 3 g/L of Lipozyme TL IM, molar ratio of 1:5 (naringin:acyl donor), reaction temperature of 40 °C, and acetonitrile as the reaction solvent. Under this condition, the maximum conversion to naringin acetate from acetic anhydride and vinyl acetate was achieved at approximately 98.5% (8 h) and 97.5% (24 h), respectively. Compared to the previously reported values, a high conversion was achieved within a short time, confirming the commercial potential of the process.

Immobilization of Candida rugosa lipase on magnetic chitosan beads and application in flavor esters synthesis

In this work, magnetic chitosan (MCH) beads were synthesized by phase-inversion method, and grafted with polydopamine (PDA) and then used for direct immobilization of Candida rugosa lipase by Schiff base reaction. The amount of immobilized enzyme and the retained activity were found to be 47.3 mg/g and 72.8%, respectively, at pH 7.0, and at 25 °C. The apparent Km (9.7 mmol/L), and Vmax (384 U/mg) values of the immobilized lipase were significantly changed compared to the free lipase. The MCH@PDA-lipase was better thermal and storage stability at different temperatures than those of the free lipase. In hexane medium, the esterification reaction results showed that the maximum conversions of isoamylalcohol and isopentyl alcohol to isoamyl acetate and isopentyl acetate using the MCH@PDA-lipase were found to be 98.4 ± 1.3% and 73.7 ± 0.7%, respectively. These results showed that the MCH@PDA-lipase can be used as an operative immobilized enzyme system for many biotechnological applications.

7-Docosahexaenoyl-Quercetin

Fatty acids and polyphenols represent different classes of pharmacologically active molecules. Hybrid derivatives of these compounds are interesting therapeutic tools. They could be obtained using enzymatic approaches, which allow regioselective derivatizations. In this short note, the pancreatic porcine lipase was employed to mediate the regioselective synthesis of 7-docosahexaenoyl-quercetin was described. The C-7 regioisomer formation was confirmed by 1H-NMR experiment. Generally, in this approach the alcoholic OH- was preferred when present. Nevertheless, in this case, it was demonstrated that the hindrance of the acyl group is a variable to obtain a good regioselectivity in C-7 position, employing only one-step reaction.

Enzymatic acylation of rutin with benzoic acid ester and lipophilic, antiradical, and antiproliferative properties of the acylated derivatives

Rutin (3',4',5,7-tetrahydroxy-flavone-3-rutinoside) was enzymatically acylated with benzoic acid and its esters (methyl benzoate and vinyl benzoate) using Thermomyces lanuginosus lipase (Lipozyme TLIM). The acylation reaction was optimized by varying the reaction medium, reaction temperature, acyl donor, substrate molar ratio, and reaction time. The highest conversion yield (76%) was obtained in tert-amyl alcohol (60 °C, 72 hr) using vinyl benzoate (molar ratio of 1:10) as acyl donor. The acylation occurred at the 2'''-OH and 4'''-OH of the rhamnose unit and the 2''-OH position of the glucose moieties. Three novel rutin acylated derivatives (compounds 1-3) were purified and characterized by HR-MS and 1D and 2D NMR spectroscopy. We found that acylation significantly improved lipophilicity, capacity to inhibit lipid peroxidation, anticancer capacity and substantially maintained the antioxidant activity of rutin. This research provides important insights in the acylation of flavonoids with different glycosyl moieties. PRACTICAL APPLICATION: In this study, three novel rutin derivatives were successfully synthesized and the highest conversion yield (76%) was obtained by reacting the rutin and vinyl benzoate at molar ratio of 1:10 in tert-amyl alcohol for 72 hr at 60 °C. Introducing a benzoic acid substituent into rutin molecule significantly improved their lipophilicity and inhibition of lipid peroxidation in lipophilic system. Furthermore, this study demonstrated that acylation significantly improved anticancer capacity and substantially maintained the antioxidant activity.

Study on the Extraction Technology of Candida antarctica Lipase B by Foam Separation

Candida antarctica Lipase B (CALB) has a wide range of applications in many fields. In this study, Pichia pastoris was used to express CALB for fermentation tank culture. Sodium dodecyl sulfate (SDS) was used as a surfactant, and foam separation technology was used to explore the best experimental conditions for the harvest of CALB. The results showed that the optimal technological conditions for the foam separation and recovery of CALB were as follows: liquid volume was 150 mL, separating gas velocity was 600 mL/min, pH value was 7, and surfactant SDS concentration was 0.5 mg/mL. Under these conditions, the enrichment ratio of CALB was 0.95, and recovery rate R was 80.32%, respectively, indicating that the foam separation technology is feasible to extract lipase B.

Structural Modifications of a Flaxseed Lignan in Pursuit of Higher Liposolubility: Evaluation of the Antioxidant and Permeability Properties of the Resulting Derivatives

While lignans and their biogenetic precursors can have various health benefits, the poor liposolubilities of such phenolic systems have restricted their application as antioxidants in the food industry. The research reported here was aimed at addressing these matters through derivatizing certain forms of such compounds and then assessing their properties as potential nutraceuticals. In particular, crude flaxseed lignan was purified to afford secoisolariciresinol diglucoside (SDG, 1) that was then subjected to structural modification. By such means, the SDG long-chain fatty acid esters 4-9 and 11-13, the fully acetylated SDG 10, secoisolariciresinol (SECO, 2), and anhydrosecoisolariciresinol (ASECO, 14) were obtained. The antioxidant activities of these derivatives were determined while their permeability properties were evaluated. Such studies revealed that certain SDG derivatives possessing useful liposolubilities also retained their antioxidative properties, as well as being capable of permeating Caco-2 cell monolayers while being nontoxic to them. SDG fatty acid esters 4-9 and 11-13 could be developed into emulsifiers with enhanced health benefits, especially considering their improved antioxidative (ca. <11 000 μmol Trolox/g) and permeability properties. This study thus highlights strategies for the structural modification of SDG so as to generate derivatives with superior properties in terms of their utility in the food and pharmaceutical industries.

Polydatin-fatty acid conjugates are effective antioxidants for stabilizing omega 3-containing bulk fish oil and fish oil emulsions

Candida antarctica lipase B-catalysed synthesis of lipophilic esters of polydatin was investigated along with their antioxidant activities. The effects of synthesis parameters such as solvent, substrate molar ratio, enzyme concentration, addition of molecular sieves, reaction temperature and time on the production of ester were studied and optimised. The highest production of esters was obtained with acetone as the reaction solvent. The antioxidant activities of the esters were compared with those of commercial butylated hydroxytoluene (BHT) and α-tocopherol. All polydatin esters inhibited the oxidative destruction of β-carotene more effectively than did BHT and α-tocopherol. Results of thiobarbituric acid tests showed that in bulk fish oil, all esters were more effective than α-tocopherol at 2 mmol/kg concentration but were not as effective as BHT. In fish oil-emulsions, all esters were more effective than both BHT and α-tocopherol at 2 mmol/kg concentration. The synthesized polydatin esters are promising antioxidants for oil/fat-based foods.

Quercetin-3-oleate

Polyphenols are well-known health promoting agents, but they have some limitations due to their spontaneous oxidation. This evidence has limited their use as drugs in recent years. In this field, several chemical modifications have been proposed to overcome these restrictions; among these, esterification seems to be the preferred modification. Ester derivatives may be able to reduce the bioavailability problems connected to polyphenols. On the other hand, the presence of esterase enzymes in the body guarantees ester hydrolysis, which in turn frees the two molecules that make it up. Lipase-catalyzed esterifications gave birth to several derivatives of flavonoids glycosides, in green conditions. In this short paper, pancreatic porcine lipase was firstly used as a cheap bio-catalyst, to synthesize oleoyl derivatives of quercetin in aglycone form. The results demonstrated how the enzyme is able to promote a regioselective acylation on C-3 position, with high yields and easy purification processes.

Selective enzymatic lipophilization of anthocyanin glucosides from blackcurrant (Ribes nigrum L.) skin extract and characterization of esterified anthocyanins

Anthocyanins (ANC) are hydrophilic and water-soluble polyphenolic plant pigments. The current barriers to successful application of ANC in the food, cosmetic and pharmaceutical industries are predominantly related to performance, stability, formulation properties, and color. Enzymatic acylation of ANC could increase their stability without compromising bioactivity and chromatic features. Lipophilization of ANC-rich blackcurrant skin extract with Candida antarctica lipase B and octanoic acid was selective to cyanidin and delphinidin glucosides, but not the corresponding rutinosides. The reaction was chemo- and regioselective for acylation at the primary alcohol of the glucose moieties, greatly facilitating separation of the different glycoside derivatives.