Cetyl Oleate Research Articles

Low-Temperature Esterification to Produce Oleic Acid-Based Wax Esters Catalyzed by 4-Dodecylbenzenesulfonic Acid

Synthesized oleic acid-based wax esters (e.g., cetyl oleate), which can replace spermaceti oil or jojoba oil, have been widely used in the cosmetic, pharmaceutical and other industries. In this work, 4-dodecylbenzenesulfonic acid (DBSA) has been successfully used as an efficient catalyst to synthesize oleic acid-based wax esters through esterification at 40 °C under solvent-free conditions. A 93.6% conversion rate of cetyl alcohol was obtained under optimal conditions: 10 mol% DBSA, a molar ratio of 1.3:1 oleic acid to alcohol, a reaction temperature 40 °C and a reaction time of 4 h. The effect of water content on esterification was investigated, and it was found that the inhibitory effect of water decreased significantly with increasing temperature. Moreover, DBSA-catalyzed esterification could be applied in the production of various oleic acid-based wax esters and excellent conversion (>90%) to esters was obtained under such mild conditions. DBSA-catalyzed low-temperature esterification is an efficient method for the production of liquid wax esters.

Enzymatic synthesis of cetyl oleate in a solvent-free medium using microwave irradiation and physicochemical evaluation

A cosmetic ester, cetyl oleate was synthesized using microwave irradiated system. The esterification reaction was carried using Candida antarctica lipase B in a solvent-free media. The influence of various reaction parameters was studied, and the efficiency of Fermase CALBTM10000 was compared with other enzymes. Equilibrium conversion of 97.5% was obtained within 20 min at 60 °C temperature, 1:2 oleic acid to cetyl alcohol molar ratio and 4% w/w dose of lipase. A comparative study showed that microwave irradiation is a much more efficient method than ultrasound irradiation and conventional heating. Fermase CALBTM10000 was reusable over 6 enzymatic cycles as its stability improved under microwave system. Physicochemical parameters of cetyl oleate were tested in order to analyze its suitability for further cosmetic use.

A novel functionalized SiO2-based support prepared from biomass waste for lipase adsorption

In this study, a novel support (Phenyl–SiO2) has been prepared via functionalization of rice husk silica (RHS) with triethoxy(phenyl)silane. For such a purpose, the functionalized support was used to immobilize lipase from Thermomyces lanuginosus (TLL) by physical adsorption via hydrophobic interactions. Introduction of phenyl groups on the support surface has been confirmed by SEM, TEM, AFM, B.E.T. and elemental analysis. Maximum immobilized protein concentration of 27.7 ± 2.3 mg/g was achieved using an initial protein loading of 40 mg/g. The catalytic activity of the prepared biocatalyst was assayed by olive oil emulsion hydrolysis, thus resulting in 655.6 ± 31.9 U/g. It was also used as biocatalyst to synthesize cetyl oleate, an important long-chain alkyl ester with emollient properties, via direct esterification in a solvent-free system. Maximum conversion of 92% after 330 min of reaction has been observed. Moreover, it fully retained its initial activity after seven successive batches. These results demonstrate that RHS functionalization is an effective strategy to prepare an active and stable biocatalyst for the synthesis of cosmetic ester.

Kinetic and thermodynamic studies on the enzymatic synthesis of wax ester catalyzed by lipase immobilized on glutaraldehyde-activated rice husk particles.

Commercial lipase from Thermomyces lanuginosus has been immobilized on glutaraldehyde-activated rice husk particles via covalent attachment. It was reached maximum immobilized protein concentration of 27.5 ± 1.8mgg-1 of dry support using the initial protein loading of 40mgg-1 of support. The immobilized biocatalyst was used to synthesize cetyl oleate (wax ester) via direct esterification of oleic acid and cetyl alcohol. The influence of relevant factors on ester synthesis, such as reaction temperature, biocatalyst concentration, presence or lack of hydrophobic organic solvents, acid:alcohol molar ratio, and reaction time has been evaluated. The experimental data were well fitted to a second-order reversible kinetic model to determine apparent kinetic constants. Thermodynamic studies have revealed that the reaction was a spontaneous and endothermic process. Under optimal experimental conditions, it was observed maximum ester conversion of 90.2 ± 0.6% in 9h of reaction time in hexane medium using 1M of each reactant (cetyl alcohol and oleic acid), at 50°C and biocatalyst concentration of 15% m/v of reaction mixture. Similar conversion (91.5 ± 0.8%) in a solvent-free system was also obtained within 24h of reaction. The biocatalyst retained 85% of its initial activity after 12 cycles within 9h of reaction in hexane medium. The physicochemical properties of purified ester have been determined in accordance with ASTM standards. The results indicate that the prepared biocatalyst has great potential for wax ester synthesis due to its satisfactory catalytic activity and operational stability.

Lipase catalysed synthesis of cetyl oleate using ultrasound: Optimisation and kinetic studies

The current paper exemplifies the application of ultrasound technology to enzymatic synthesis of a cosmetic emollient ester, cetyl oleate. Fermase CALB™10000, a commercial Candida antarctica lipase B was used as a catalyst to accomplish the ultrasound supported synthesis. Multiple process parameters like reaction time, temperature, enzyme dose, alcohol to acid molar ratio, ultrasound power, frequency and speed of agitation were optimised. Maximum conversion of ∼95.96% was discerned at optimum conditions, i.e., 60°C temperature, 5% enzyme dose, 2:1 alcohol:acid ratio, 60W ultrasound power, 25kHz ultrasound frequency, 80% duty cycle and 80rpm speed of agitation after purification steps. It was observed that the reaction reached equilibrium in a short duration of 30min under the optimised conditions. This was considerably lesser than the time required for attaining equilibrium in conventional mechanical stirring method which was over 2h. Bisubstrate kinetic models like random bi–bi, ping pong bi–bi and ordered bi–bi were applied to the experimental data to determine initial rates and other kinetic parameters. Ordered bi–bi model showed the best fit with kinetic parameters, Vmax=0.029M/min/gcatalyst, KA=0.00001M, KB=4.8002M, KiA=0.00014M, KiB=3.7914M & SSE=0.00022 for enzymatic cetyl oleate synthesis under ultrasound irradiation with inhibition by both acid and alcohol at high concentrations.

Synthesis of Wax Esters from Crude Fish Fat by Lipase of Burkholderia sp. EQ3 and Commercial Lipases

AbstractThe lipase from Burkholderia sp. EQ3 was used to synthesize wax esters in comparison with commercial lipases. The supernatant of Burkholderia sp. EQ3 was collected from a liquid basal medium with 1 % fish oil after 12 h cultivation (1.90 U/ml of lipase activity). The crude lipase was prepared by acetone precipitation of the culture supernatant (4.70 U/mg and 9.40 purification folds). The crude fish fat obtained by hexane extraction of waste fat from the wastewater pond of a canned tuna factory and cetyl alcohol were used for wax esters synthesis. Five commercial lipases were screened in comparison with crude lipase from Burkholderia sp. EQ3 in wax esters synthesis. The optimum conditions for wax esters synthesis from crude fish fat using Novozyme 435 were enzyme 1 U, substrate molar ratio of crude fish fat to cetyl alcohol 1:2 (115.30 mg of crude fish fat and 66.67 mg of cetyl alcohol) in hexane at 37 °C and 200 rpm with 90.81 % (TLC–FID peak area) after one h of reaction. The optimum conditions for the synthesis by crude lipase from Burkholderia sp. EQ3 were crude lipase 40 U, substrate molar ratio of crude fish fat and cetyl alcohol 1:2 in isooctane at 30 °C and 200 rpm with 95.07 % (TLC–FID peak area) after 6 h of reaction. The synthesized wax esters were mainly composed of cetyl palmitate and cetyl oleate.

Optimization of Immobilized Lipase-Catalyzed Synthesis of wax Esters by Response Surface Methodology

Wax esters have a variety of biotechnological usage in cosmetic and pharmaceutical products. Synthesized wax esters can be an alternative to sperm whale being rare. The ability of a non-commercial immobilized lipase from Rhizopus oryzae to catalyze the synthesis of wax esters was investigated in organic media. Wax esters were obtained by esterification of myristic, palmitic, stearic or oleic acids with cetyl alcohol. Response surface methodology was used to evaluate the effects of the temperature, the enzyme amount and the volume of hexane on the wax esters production yields. Under optimal conditions, high conversion yields (92-95%) of saturated fatty acids were reached within a reaction time of 30 min whereas a yield of 93.5% was obtained for cetyl oleate after 60 min. The synthesized esters were purified using a silica gel column. The immobilized Rhizopus oryzae lipase was successfully reused in 20 repeated cycles with no significant decrease in the final conversion yields. This makes it a promising candidate for the development of a highly effective set-up for the production of wax esters. Keywords: Central composite design, cosmetic and pharmaceutical industries, Immobilized Rhizopus oryzae lipase, response surface methodology, wax esters

Synthesis of Wax Esters by Lipase-catalyzed Esterification with Immobilized Lipase from Candida sp. 99–125

Wax esters were synthesized in a solvent free system catalyzed by immobilized lipase from Candida sp. 99-125, with oleic acid and cetyl alcohol. The effects of substrate molar ratio, lipase dosage and water removal were investigated in a 50 ml flask incubated in a thermostatic cultivation cabinet. The optimized conditions were: temperature 40°C, shaking at 170 r·min −1, acid/alcohol molar ratio 1:0.9, lipase dosage in 10% (by mass) of oleic acid, and open reaction for water removal. As a result, the conversion rate reached 98% for reaction of 8 h. The volume of reactor was scaled up to 1 L three-neck flask. The optimized parameters were: 200 r·min −1 agitation speed, 2.5% (by mass) lipase dosage, others were the same as the parameters described above. The conversion rate reached 95% for reaction of 24 h. The lipase retained 46% conversion rate after reuse for 6, 7 batches. The products were purified by removing remained cetyl alcohol and fatty acids with ethanol and saturated sodium carbonate solution, respectively. The purity of the wax ester, cetyl oleate, was 96%. The physical and chemical properties of cetyl oleate were tested and compared with those of jojoba oil. The results show that the product cetyl oleate has great potential to use as the substitute of natural jojoba oil.

Wax esters synthesis from heavy fraction of sheep milk fat and cetyl alcohol by immobilised lipases

Wax esters were obtained from lipase-catalysed alcoholysis of triglycerides with cetyl alcohol, using n-hexane as solvent. The heavy triglyceride fraction (HTF), obtained by fractionation of sheep milk fat, was used as raw material. In the natural fat mixture GC analysis showed that palmitic, myristic, stearic and oleic acids are the most abundant fatty acids which are useful to produce wax esters. Reactions were tested for different amounts of Lipozyme RMIM catalyst, and the optimum concentration of 10 mg catalyst/ml solution has been determined. The formation of the four main products, i.e. cetyl myristate, cetyl palmitate, cetyl oleate and cetyl stearate, was determined by HPLC/ELSD quantitative analysis. The optimum water activity in the reaction medium a w=0.35 in the case of Lipozyme RMIM, and a w=0.53 for Novozym 435 was found. Lipozyme RMIM (immobilised sn-1,3-specific lipase from Rhizomucor miehei) was more active than Novozym 435 (immobilised nonspecific lipase-B from Candida antarctica) towards wax esters production. The acyl migration of 2-monoglycerides was suggested as a crucial step to explain the higher yields produced by the 1,3-specific lipase.

Kinetic modelling of esterification reactions catalysed by immobilized lipases

The kinetics of the synthesis of several esters of different chain length and physical properties was studied. A commercial Candida antarctica lipase was used as catalyst for the synthesis of oleyl oleate, isopropyl oleate, isopropyl palmitate, myristyl myristate, cetyl oleate, and oleyl 2-methylbutyrate. A general kinetic model was derived and tested experimentally for the synthesis of the above esters. The general kinetic model took a different shape for each particular esterification reaction, depending on the significance of the different terms. The corresponding parameters were calculated by non-linear regression. The kinetic models were found to describe the experimental values adequately.

Cetyl Myristoleate Isolated from Swiss Albino Mice: An Apparent Protective Agent against Adjuvant Arthritis in Rats

Cetyl myristoleate was Isolated from National Institutes of Health, general purpose, Swiss albino mice that were immune to the polyarthritis induced in rats with Freund’s adjuvant. This substance, or material synthesized from cetyl alcohol and myrlstoleic acid, afforded good protection against adjuvant-induced arthritic states in rats. In limited comparisons, cetyl oleate, also found in Swiss albino mice, gave lesser protection, whereas cetyl myristate and cetyl elaldate, the frans-isomer of cetyl oleate, appeared to be virtually ineffective. Dosage of the protective compound as well as the site of injection of Freund’s adjuvant was important.

Gastrointestinal transit and lipid assimilation efficiencies in three species of sub‐antarctic seabird

AbstractUsing tritium‐labeled glycerol triether ([3H] GTE) as a nonabsorbable lipid‐phase marker and tritium‐labeled polyethylene glycol 4000 ([3H] PEG) as a nonabsorbable aqueous‐phase marker, we examined gastrointestinal transit of homogenized Antarctic krill (Euphausia superba) meals fed to white‐chinned petrels (Procellaria aequinoctialis), sooty albatrosses (Phoebetria fusca), and rockhopper penguins (Eudyptes chrysocome). The aqueous‐phase marker was excreted significantly more rapidly than was the lipid‐phase marker by the two procellariiform species, whereas no differential transit rates for the two markers were observed in the penguins. Aqueous‐phase marker recoveries after 48 hours from the three species were statistically indistinguishable (78.6% ± 3.7%, n = 5; 71.9% ± 11.3%, n = 7; and 77.0% ± 9.4%, n = 4, respectively). Lipid‐phase marker recovery from the penguins after 48 hours was nearly complete (83.8% ± 19.3%, n = 5, and 92.7% ± 14.8%, n = 5, for two dietary lipid supplements, see below), whereas less than 50% of the original dose of lipid marker was recovered from the two procellariiform species. Substantial lipid‐phase marker was recovered as stomach oils from the procellariiforms.Assimilation efficiencies of [1‐14C] tripalmitin dissolved in wax ester and [1‐14C] cetyl oleate dissolved in triglyceride were compared for the same three seabirds by comparing 3H/14C ratios in the food and feces of birds simultaneously fed one of the above 14C‐labeled lipids, and the non‐metabolizable marker [3H] GTE. The petrel and the albatross showed high assimilation efficiencies (> 80%) of both 14C‐labeled neutral lipids. Rockhopper penguins consistently excreted [3H] GTE faster than did adult sooty albatrosses and were significantly less efficient at assimilating both neutral lipids (62% and 45% respectively). Sooty albatross fledglings excreted lipids significantly more slowly than did adults of this species, but lipid assimilation efficiencies did not differ with age. Gut measurements showed that the intestine of the rockhopper penguin was three and six times as long as those of the sooty albatross and white‐chinned petrel respectively.

Assimilation and deposition of dietary fatty alcohols in Leach's storm petrel, Oceanodroma leucorhoa

AbstractThe diet of Leach's storm petrel (Oceanodroma leucorhoa) chicks has a high lipid content (up to 60% of fresh mass), and, for certain populations, much of the dietary lipids are wax esters (up to 70% of total lipid). In order to determine the metabolic fate of dietary wax esters, we fed chicks [1‐14C]cetyl oleate in either a low wax (20%, w/w) or a high wax (80%, w/w) mixture of wax ester and triacylglycerols. Wax ester in the stomach remained unhydrolyzed for extended periods, with up to 38% of the label still unassimilated after 36 hr. Hydrolysis occured principally in the duodenum, where the fatty alcohol product was rapidly oxidized to fatty acid, apparently at the intestinal epithelia. Assimilated label was primarily metabolized and respired as carbon dioxide, with most of the remainder incorporated into triacylglycerols and deposited in storage fat depots. Hydrolysis of wax ester and assimilation of the fatty alcohol moiety were extremely efficient, with less than 0.2% of ingested label excreted. Assimilation efficiencies for label in low wax and high wax meals were statistically indistinguishable. Chicks fed 20% (w/w) [1‐14C]cetyl alcohol in triacylglycerols had similar assimilation efficiencies as those fed labeled wax ester, indicating that hydrolysis of the ester linkage does not limit wax ester assimilation. This study suggests that sea birds can possess an efficient means for metabolizing wax esters, an abundant energy source in the marine environment, which have previously been thought to be difficult to assimilate.

SOME PHYSIOLOGIC CHARACTERISTICS OF ESTERS OF CETYL ALCOHOL

Palmitic, oleic, and butyric acid esters of cetyl alcohol were fed to mature rats. Cetyl palmitate was quantitatively excreted in the feces and produced no physiologic aberration. While cetyl oleate was 75% absorbable, it was of little value as an energy source and was partially excreted through the skin. Feeding of cetyl butyrate also induced seborrhea. Data on free fatty acids in gastrointestinal contents and on the specificity of seborrheic lipids indicate that cetyl esters are largely absorbed without hydrolysis, if the fatty acid moiety is readily absorbable, and excreted by way of the skin without modification.

SOME PHYSIOLOGIC CHARACTERISTICS OF ESTERS OF CETYL ALCOHOL

Palmitic, oleic, and butyric acid esters of cetyl alcohol were fed to mature rats. Cetyl palmitate was quantitatively excreted in the feces and produced no physiologic aberration. While cetyl oleate was 75% absorbable, it was of little value as an energy source and was partially excreted through the skin. Feeding of cetyl butyrate also induced seborrhea. Data on free fatty acids in gastrointestinal contents and on the specificity of seborrheic lipids indicate that cetyl esters are largely absorbed without hydrolysis, if the fatty acid moiety is readily absorbable, and excreted by way of the skin without modification.

On the Production of Seborrhea in Rat by Feeding with whale Oil. Part I

1. When rats were fed on sperm head oil as well as on arctic sperm oil (oils of skin, muscle and bone), adding 10_??_15% in the diet, an oily substance diffused out from the skin and the animals show such an appearance as if they were dipped in oil. Besides, the above oils are very noxious, retarding the growth and finally causing the death of animals in a few weeks. 2. The above symptom produced by the whale oil cannot be prevented by adding 15% yeast in the diet, though the toxicity seems to be somewhat reduced, but rather the addition of yeast favor the development of more conspicuous symptom. 3. Saponification products of whale oil, namely, fatty acids and unsapo-nifiable matter, produced no such symptom as the original oils, but the toxicity was stronger than the latter. Moreover, it is not decided whether or not the substance which causes seborrhea is identical with that which prevents the growth of the animal. 4. The severe symptom appeared on these animals which grew relatively well with good food intake. 5. The oleic acid ester of oleyl alcohol synthetically prepared by the author exerted the same effect as whale oil, but oleyl palmitate or cetyl oleate gave no such phenomena. In conclusion, the author wishes to express his sincere thanks to Prof. U. Suzuki for his kind guidance. Thanks are also due to the Tokai Fishery Company and to Mr. K. Tashima for their kindness in supplying the materials.