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The synthesis of feruloylated coconut oil and feruloylated shea butter were demonstrated in 0.5-L scale, shaken, batch reactions. Ethyl ferulate and the vegetable oil/fat were combined in a 1.0:1.3 mol ratio in the presence of Candida antartica lipase B immobilized on an acrylic resin (Novozym 435) at 60 °C. The transesterification of ethyl ferulate with coconut oil and shea butter reached equilibrium conversions, after 22 days, of 63 and 70%, respectively, with the shea butter transesterifications producing a white precipitate not observed in the coconut oil transesterifications. The faster transesterification rates, equilibrium conversions and white precipitate were shown to result from di- and monoacylglycerols (DAG and MAG) present in the shea butter. The transesterification of ethyl ferulate and coconut oil was also tested in a continuous, enzymatic, packed-bed bioreactor using Novozym 435 at 60 °C to produce feruloylated coconut oil at rates of 0.5–0.9 kg/day over 4.5 months. The feruloylated coconut oil acylglycerol species were identified by LC–MS analysis of transesterification reactions of ethyl ferulate with medium chain triacylglycerol (TAG) standards, C8–C14. The feruloylated vegetable oils possessed an ultra violet (UV) absorbing λ max 328 nm, making them good UVAII absorbers, as defined by the U.S. Food and Drug Administration. The feruloylated coconut oil possessed a 17.5% higher absorption capacity than feruloylated shea butter on a per weight basis. All the feruloylated vegetable oils possessed rapid antioxidant capacity (50% reduction of initial radical concentration

Seven lipoate esters were synthesized by esterification of lipoic acid with different structures of alcohols in the presence of a solid acid catalyst and without solvent. The esters were obtained in good yield, characterized using 1H NMR and GPC; and their physical properties investigated. Four of the seven lipoate esters, with good solubility in high oleic sunflower oil (HOSuO) and polyalphaolefin (PAO6) base oils, were further investigated for their lubricant additive property. Additive properties were investigated in HOSuO base oil by varying the additive concentrations in the range 0–20 (w/w %). Properties investigated include: density; kinematic and dynamic viscosity; viscosity index (VI); oxidation stability from onset and peak oxidation temperatures on a PDSC; 4-ball antiwear (AW); and 4-ball extreme pressure (EP). Neat lipoate esters displayed high oxidation stability and high VI. As additives to HOSuO base oil, lipoate esters displayed good viscosity index improver (VII), good antioxidant, good e...

The synthesis of feruloyl soy glycerides was demonstrated on a pilot-scale (1 metric ton/year) in a continuous, four-column series, packed-bed, enzymatic bioreactor (herein referred to as the bioreactor). Ethyl ferulate and soybean oil were combined and converted at 3.5 kg/d over Candida antarctica lipase B immobilized on an acrylic resin (Novozym 435) at 60 °C. The ethyl ferulate/soybean oil substrate was fed through the four, packed-bed, enzyme columns in series with each column fitted with a recirculation pump, which improved conversion and throughput compared to smaller, batch bioreactor systems. The synthesis was carried out over 4.5 months with a single charge of enzyme to produce over 450 kg of feruloyl soy glycerides at 65% conversion. The stability of the feruloyl soy glycerides was determined by comparing the total ferulate concentration (UV absorbance), free radical scavenging (antioxidant) capacity, total acid value (hydrolysis), and Lovibond color of samples produced in 2009 to samples produced in 2015. The feruloyl soy glycerides showed no appreciable loss of UV absorbing ( λ max 325 nm) or rapid antioxidant capacity (50% reduction of initial radical concentration

Lipoyl glycerides were synthesized by enzymatic transesterification of lipoic acid with high-oleic sunflower oil in 2-methyl-2-butanol solvent. The synthesis gave a crude product mixture comprising unreacted lipoic acid, free fatty acids, and several lipoyl glyceride structures of varying lipoic acid substitution. A more purified product mixture, devoid of unreacted lipoic acid and free fatty acids, was obtained in 61% yield. The crude and purified product mixtures were thoroughly characterized and their components positively identified. The tribological properties of the product mixtures were further investigated using a variety of methods. The product mixtures displayed significantly improved oxidation stability, cold-flow, and extreme pressure properties over those of the parent high-oleic sunflower oil. The extreme pressure results for the neat products showed a higher weld point for the crude than for the purified mixture. This was attributed to differences in the chemical properties of the components in the two product mixtures.

Soybean oil 2-monoacylglycerol (2-MAG) was synthesized via the Novozym 435-catalyzed ethanolysis of triacylglycerols and purified by conventional liquid–liquid extraction. The 2-MAG was subjected to incubation at 20 and 40 °C in the presence of five solid commercial support materials, Lewatit, Silica Gel 60, Alumina–Neutral Brockman Activity 1, Amberlyst-15, and SBA-15, to determine their effects on acyl migration rates. Lewatit and SBA-15 did not catalyze acyl migration rates after 144 h, while silica gel slightly increased migration rates. The more polar alumina and the cationic Amberlyst 15 significantly increased migration rates. Flash chromatography purification of 2-MAG using silica gel as the immobile phase developed with an acetone/hexane binary gradient proved to be a comparable purification method to liquid–liquid extraction, resulting in 60 % 2-MAG yield, no residual triacylglycerol, diacylglycerol, or glycerol co-products, and a 95 mol% 2-MAG purity vs. 1-MAG, demonstrating that flash chromatography did not catalyze acyl migration.

The natural plant components, 1-feruloyl- sn -glycerol (FG) and 1,3-diferuloyl- sn -glycerol (F 2 G), were synthesized by the enzymatic esterification of glycerol and soybean oil mono- and diacylglycerols, respectively, with ethyl ferulate. The isolated FG and F 2 G were examined for their antioxidant activities as free radical scavengers (DPPH assay) and peroxyl lipid oxidation inhibitors (TBARS assay). The H atom transfer kinetics, as monitored by DPPH free radical bleaching, of FG showed that the mono-feruloyl glycerol acted as a rapid antioxidant (50% reduction of DPPH radical 2 G and ferulic acid activity rates were in the range of intermediate antioxidants (50% reduction of DPPH radical in 5–30 min). FG and F 2 G showed similar activity as the control agent, ethyl ferulate, towards the inhibition of the AAPH-induced peroxyl radical oxidation of surfactant emulsified γ-linolenic acid. A slight excess of feruloyl groups was sufficient to completely suppress the formation of secondary lipid oxidation products.

1,3-Diferuloyl-sn-glycerol is found ubiquitously throughout the plant kingdom, possessing ultraviolet adsorbing and antioxidant properties. Diferuloyl glycerol was synthesized and isolated as a byproduct in up to 5% yield from a pilot plant scale packed-bed, biocatalytic transesterification of ethyl ferulate with soybean oil or mono- and diacylglycerols from soybean oil. The yield of the diferuloyl glycerol byproduct was directly proportional to the overall water concentration of the bioreactor. The isolated diferuloyl glycerol exhibited good ultraviolet adsorbing properties, 280-360 nm with a lambda(max) 322 nm, and compared well to the efficacy of commercial sunscreen active ingredients. The antioxidant capacity of diferuloyl glycerol (0.25-2.5 mM) was determined by its ability to scavenge 2,2-diphenyl-1-picrylhydrazyl radicals and was comparable to that of ferulic acid. At current pilot plant scale production capacity, 120 kg diferuloyl glycerol byproduct could be isolated per year.

A liquid carbon dioxide counter-current fractionation method was developed to remove by-product fatty acid propyl esters (FAPEs) from the reaction mixture after the partial deacylation of sunflower oil. The fractionation column was 1.2 m long and separations were done at 25 °C and 8.27 MPa. Several solvent to feed ratios (S:FR) (i.e., 7.6, 15.2, 30.3 and 60.6 g/g) and feed rates (FR) (i.e., 1, 2, 2.5, 3 and 4 mL/min) at a constant S:FR of 15.2 were examined. Raffinate purity (i.e., percentage glycerides) and extract purity (i.e., percentage FAPEs) were both monitored. Percentage glycerides in both the raffinate and the extract increased with S:FR. The raffinate contained ca. 83, 97, 100 and 100% glycerides at S:FRs of 7.6, 15.2, 30.3 and 60.6, respectively. The percentage glycerides in the extracts were ca. 3, 4, 8 and 17%, respectively. With the S:FR held constant at 15.2, the raffinate purity peaked at ca. 99% glycerides at a FR of 2.5 mL/min and the extract at this FR contained ca. 96% FAPEs. The optimal S:FR and FR determined from the experimental assays was applied to large batches in both a semi-continuous feed mode, and later in a continuous feed mode, which gave raffinates of 99.3 and 98.1% glycerides, respectively, and extracts of 97.3 and 97.2% FAPEs, respectively.

High oleic sunflower oil (HOSO) and soybean oil (SBO) were partially deacylated by enzyme-catalyzed propanolysis using lipozyme TL IM to form 1,2-diacyl- sn -glycerols (1,2-DAG) in 40% yields. 1,2-DAG are of interest as potential regiospecific intermediates in the synthesis of structured lipids for cosmeceutical and nutriceutical applications. Two purification techniques were examined to determine which was the most efficient at removing the fatty acid propyl ester (FAPE) byproducts while limiting the spontaneous acyl migration of the 1,2-DAG to 1,3-diacyl- sn -glycerols (1,3-MAG) and adversely affecting the physical properties of the 1,2-DAG and FAPE. Molecular distillation of the partially deacylated vegetable oils was examined at temperatures ranging from 120 to 240 °C. Molecular distillation at 220 °C removed 77% of the FAPE byproduct but caused significant acyl migration. Additionally, the acid values and Lovibond color of the partially deacylated vegetable oils were deleteriously affected. The purity of the FAPE, contaminated by co-distillation of di- and mono-acylglycerol species as monitored by viscosity values and 1 H NMR, was also compromised by the high temperature distillation. Distillations at lower temperatures improved the physical properties of the partially deacylated vegetable oils and the purity of the FAPE but at the sacrifice of the efficiency of FAPE removal. The mild condition of the liquid CO 2 extraction afforded the most efficient removal of the FAPE, 96%, while causing no appreciable acyl migration, and resulted in acid values and Lovibond colors comparable to those obtained at the lowest molecular distillation temperatures studied.

The acyl migration kinetics of long-chain 1,2-diacylglycerol (1,2-DAG) to form 1,3-diacylglycerol (1,3-DAG) over the temperature range of 25–80 °C were examined using 1H-NMR spectroscopy. Lipase-catalyzed ethanolysis of high-oleic sunflower oil, followed by a series of solvent extraction steps, generated high purity 1,2-DAG (0.93 mol fraction of the DAG content). The 1,2-DAG mole fraction of 0.32 at equilibrium was found to be insensitive to temperature, indicating that long-chain acyl group migration is neither endothermic nor exothermic. Determination of the temperature-dependent, first-order reaction kinetic parameters revealed a 1,2-DAG half life (t 1/2) of 3,425 h and 15.8 h at 25 and 80 °C, respectively. A comparison of 1,2-DAG with 2-monoacylglycerol indicated that there is no difference between the two in the potential energy state (ΔG ‡) of their respective transitions states or cyclic intermediates.

The enzymatic reaction of soybean oil (SBO) triacylglycerides (TAGs) with ethyl ferulate (EF) produces the product feruloylated acylglycerols, called SoyScreen™ as well as by-product fatty acid ethyl esters (FAEEs). Both the unreacted EF as well as the by-product FAEEs must be removed from the mixture before the feruloylated acylglycerols can be used as natural sunscreens and/or antioxidants. This research investigated the use of a continuous liquid carbon dioxide (L-CO 2 ) counter-current fractionation method to purify a model mixture representing the crude enzymatic mixture from the synthesis of SoyScreen™. The effect of column length, solvent to feed ratio (S:FR) and feed rate were examined. Raffinate purity increased with both column length and S:FR. When the feed rate was doubled while the S:FR was held constant, there was essentially no loss of raffinate purity. Using L-CO 2 (23–25 °C and 11.0 MPa), a 120 cm long packed column, a S:FR of ca. 11.9, the raffinate was essentially free of both EF and FAEEs at feed rates of either 0.464 or 0.927 g/min with ca. 90% yield.

The acyl migration kinetics of neat 2-monoacylglycerol (2-MAG) to form 1-MAG was determined using 1H NMR spectroscopy to monitor the β-proton integration ratios of the two species over time. 2-MAG was synthesized by the Novozym 435-catalyzed alcoholysis of soybean oil and isolated by solvent extraction or molecular distillation at a mole fraction (X 2-MAG) of 0.94 relative to total MAG. The kinetics parameters of the neat 2-MAG acyl migration were investigated over the temperature range of 23–80 °C. The 2-MAG mol fraction remained unchanged at 23 °C over the course of 168 h and reached an equilibrium of X 2-MAG = 0.09 at only 80 °C. Modeling of the kinetics data revealed a 2-MAG half life (t 1/2) of 3,500 and 22.8 h at 23 and 80 °C, respectively, with an activation energy of 79.0 ± 6.5 kJ mol−1. The use of 1H NMR spectroscopy proved an expedient method for monitoring the acyl migration in 2-MAG compared to other reported methods (e.g. GC, HPLC, and 13C-NMR spectroscopy), requiring no sample manipulation and minimizing the deleterious effects of high temperatures and solvent exposure.

Ferulic acid is a hydroxy cinnamic acid derivative found ubiquitously throughout the plant kingdom, is especially abundant in rice and corn bran, and possesses excellent ultraviolet (UV) and antioxidant properties. Ferulic acid was enzymatically incorporated into soybean oil to form feruloylated monoacyl- and diacylglycerols (FAG). The FAG possess the UV-absorbing and antioxidant properties of ferulic acid but are water insoluble and extremely lipophilic. These characteristics make FAG attractive in the cosmeceutical industry as an all-natural replacement for petroleum-based sunscreen active ingredients and antioxidants. The FAG were synthesized from the transesterification of soybean oil with ethyl ferulate catalyzed by the commercial lipase, Novozym 435 (Candida antartica lipase B). The FAG were encapsulated as microdroplets within a starch matrix via steam jet cooking (140 °C and 225 kPa). Up to 50% (w/w) of the feruloylated lipids was encapsulated into the starch matrix with the microdroplets ranging in size from 1 to 10 μm. Transmittance and irradiance measurements of UV radiation (300–400 nm) through thin films of neat FAG (not manipulated after FAG synthesis) and starch-encapsulated FAG showed that the FAG retained its ultraviolet-absorbing efficacy after steam jet cooking. Furthermore, starch-encapsulation of the FAG was found to enhance the ultraviolet absorbance of the feruloylated lipids. When encapsulated at 50% (w/w) in the starch matrix, one-half of the coverage (mg/cm2) of FAG was required to block the same amount or more UV radiation as neat FAG. The starch-encapsulated FAG was formulated as an aqueous dispersion without the need for emulsifiers or surfactants. The dispersions were drum dried to a powder and shown to be easily reconstituted into water dispersions without the loss of ultraviolet-absorbing efficacy.

The use of HPLC-MS to separate and identify the feruloylated acylglycerols formed during the transesterification of ethyl ferulate with TAG was examined. Novozym 435 (Candida antarctica lipase B)-catalyzed transesterifications of ethyl ferulate and soybean oil resulted in a mixture of feruloylated MAG, DAG, and TAG and diferuloylated DAG and TAG. These feruloylated acylglycerols have recently garnered much interest as cosmeceutical ingredients. The ratio of the various feruloylated acylglycerol species in the resultant oils is presumed to affect the oil's cosmetic efficacy as well as its physical (formulation) properties. Thus, it was desirable to develop an analytical method to separate, identify, and quantify the individual feruloylated acylglycerols to determine their relative ratios. The feruloylated acylglycerols were successfully separated and identified by HPLC-MS using a phenyl-hexyl reversed-phase column developed with a water/methanol/1-butanol gradient. The chromatograms of the feruloylated acylglycerols from soybean oil were convoluted by myriad fatty acids; therefore, feruloylated acylglycerols from triolein were studied as a model reaction. Hydrolysis of the feruloylated acylglycerols from triolein catalyzed by Lipase PS-C “Amano” I (Burkholderia cepacia), which showed no hydrolysis reactivity toward ethyl ferulate, allowed for the chromatographic assignment of the feruloyl acylglycerol positional isomers.

The acylglycerides of lipoic and dihydrolipoic acids may serve as slow-release sources for cutaneous delivery of these antioxidants when formulated in a liposomal vehicle.Testing was conducted to determine the storage stability of lipoyl glycerides in phospholipid-based liposomes.Lipoyl glycerides prepared by transesterification of lipoic acid with high oleic sunflower oil were incorporated into unilamellar liposomes comprised of soy phosphatidylcholine (soyPC) or dioleoylphosphatidylcholine (DOPC).Lipoyl glycerides were stable in soyPC at 4 °C (90% remaining after five weeks) and decayed with a half-life (t(½)) of 14 d at 40 °C. In contrast, lipoyl glycerides embedded in DOPC were completely stable for four weeks at 40 °C. Dihydrolipoyl glycerides in soyPC converted to lipoyl glycerides at 4 °C (t(½) = 14 d) over four weeks, and much more rapidly so at 40 °C (t(½) = 1 d). A hydroperoxide accumulation analysis indicated that lipoyl glycerides and dihydrolipoyl glycerides were modified or degraded while suppressing autoxidation of the polyunsaturated fatty acids present in soyPC. Dynamic light scattering measurements found that liposomes containing lipoyl glycerides or dihydrolipoyl glycerides did not undergo significant size changes for at least 48 d, indicating that inclusion of the lipoic acid derivatives did not induce vesicle aggregation.Substitution of the soyPC with DOPC, which is not readily subject to autoxidation, provided a much more stable storage environment for lipoyl glycerides. These findings confirm the expectation that phospholipid liposomes need to be oxidatively stable vehicles for dermal delivery of lipoic acid derivatives.