均相无溶剂法合成蔗糖酯

以生物表面活性剂为催化剂,用均相无溶剂法在不同条件下合成了蔗糖酯。小试的转化率达到５０％￣５５％,产品质量符合ＧＢ８２７２０８７标准,使蔗糖酯的合成达到了先进水平。     

The enzymatic hydrolysis and tissue oxidation of fatty acid esters of sucrose

Summary Various preparations of sucrose fatty acid esters were hydrolyzed by wheat germ or pancreatic lipase, pancreatin, pancreatic juice, α-amylase, invertase, or liver homogenates to yield sucrose and free fatty acids as products. The greatest activity was observed with the liver homogenate. None of the enzymes studied cleaved the glycosidic linkage as indicated by the lack of appearance of reducing groups and by paper chromatography of the products. The greatest hydrolysis by pancreatic lipase was observed with sucrose esters having a greater preponderance of unsaturated fatty acids, namely, sucrose trilinoleate, sucrose dilinoleate, sucrose tetralinoleate, and “Sequol 260” (69% unsaturated fatty acids). Sodium taurocholate was required for hydrolysis by pancreatic lipase but not by wheat germ lipase. Sucrose ester was inhibitory to the hydrolysis of triolein by all lipolytic preparations. Tetra-ethyl pyrophosphate and cupric ions were not inhibitory to the hydrolysis of sucrose ester. Sucrose fatty acid esters supported respiration by rat liver homogenates and to a much lesser extent by rat intestinal mucosa. The rate of oxidation was greater than that observed with sucrose and the corresponding fatty acid. The greatest activity was observed with esters of fatty acids having a greater preponderance of unsaturated fatty acids, namely, “Sequol 260,” sucrose di-, tri-, and tetralinoleate. This work was carried out under U.S.P.H.S. Grant No. A-1808 and Sugar Research Foundation Grant No. 109.     

The composition of beeswax alkyl esters

The alkyl esters of beeswax, after isolation from the unhydrolyzed wax by preparative layer chromatography (PLC), have been analyzed directly by high temperature GLC using 1.5% OV1 as liquid phase. In two commercial wax samples examined the ester homologues are predominantly even carbon numbered ranging from C₃₆ to C₅₄. The principal alkyl esters are C₄₀, C₄₂, C₄₄, C₄₆ and C₄₈. The GLC analysis of the ester hydrolysis products revealed that the variations in ester chain length are produced by variations in the esterified primary alcohol chain lengths. The esterified fatty acid is chiefly hexadecanoic acid. The esterified fatty acids differ in composition from the free fatty acids which are also present in the wax.     

Analysis of the dark-colored impurities in sulfonated fatty acid methyl ester

A fractionally distilled C₁₄−C₁₆ fatty acid methyl ester, derived from palm oil, was sulfonated with gaseous SO₃ in a falling film reactor to form an α-sulfo fatty acid methyl ester (α-SF; unbleached and unneutralized form). The included dark-colored impurities were then separated from α-SF as a diethyl ether-insoluble matter. After purification by thin-layer chromatography, the colored species were analyzed by ion-exchange chromatography, gel-permeation chromatography, and nuclear magnetic resonance spectrometry. These data suggested that the colored species were polysulfonated compounds with conjugated double bonds. Minor components in the raw fatty acid methyl ester, found by gas chromatography/mass spectrometry, were spiked into the purified methyl palmitate and then sulfonated. The unsaturated methyl ester and hydroxy ester showed the worst color results. The methyl oleate and methyl 12-hydroxystearate were then sulfonated and analyzed. Deep black products were obtained, which showed the same properties as the colored species in α-SF. It was concluded that low levels of unsaturated fatty acid methyl esters and hydroxy esters in the fatty acid methyl ester are the main causes of the coloring.     

Quantitative estimation of sucrose esters of plamitic acid

Thin layer chromatography was adapted for direct quantitative estimation of sucrose esters of palmitic acid. Urea-phosphoric acid spray was used to detect the sucrose moiety of the various esters. The photometrically metermined density density of each spot on the thin layer plate was found to be proportional to its sucrose content. Ester content was then obtained by multiplying sucrose found by the factor, mol. wt. ester/mol. wt. sucrose. Ester mixtures were prepared by interesterifying sucrose with various proportions of methyl palmitate in dimethylformamide solution. Positional isomers were observed at each level of substitution but could not be adequately separated from each other for quantitative evaluation. Presented at the AOCS Meeting, Minneapolis, October 1969. So. Utiliz. Res. Dev. Div., ARS, USDA.     

Analytik von Phosphorsäurepartialestern

Analytic of Phosphoric Acid Partial Esters Phosphoric acid partial esters are best synthesized by reaction of fatty alcohol with P₂O₅. The chosen mol ratio of fatty alcohol and P₂O₅ determines the amounts of mono-, di- and trialkylester, of oligomeric esters, of free fatty alcohol and of phosphoric acid. Several methods are used for the characterisation and determination of the individual components, the potentiometric titration, the ³¹P-nuclear magnetic resonance, the gel permeation chromatography, the ion chromatography and the supercritical fluid chromatography. The combination of all the results of the applied methods provides the key to the composition of the phosphoric acid ester. The results of the analysis are checked by a phosphorus calculation. This analytical procedure can be applied to phosphoric acid partial esters in the acid and salt form. The analysis of alkylethoxyphosphoric esters is done with the exclusion of the chromatographic methods.     

Contribution towards the glyceride structure of kamala seed oil

Kamala (Mallotus philippinensis) oil was crystallized using acetone at temperatures progressively lowered from ambient to −15C. The five fractions thus obtained were subjected to intensive analysis using a variety of methods. These included thin layer chromatography before and after hydrogenation, cryoscopic mean molecular wt determination, fatty acid analysis by ultraviolet absorption and by gas liquid chromatography of the hydrogenated silylated esters, determination of total unsaturation using the Rosenmund-Kuhnhenn reagent, hydroxyl value determination, nuclear magnetic resonance, lipase hydrolysis, ester number determination both as ferric hydroxamate complexes and infrared absorption, and glycerol determination by silylation followed by gas liquid chromatography. The evidence is consistent with the presence in kamala seed oil of polyacid glycerides carrying from 3 to 8 fatty acids.     

蔗糖酯洗涤剂去除农药残留的试验

研究了四种不同的蔗糖酯对农药残留的洗涤效果，结果发现椰子油的蔗糖酯与APG对农药残留有较好的洗涤效果。     

A rapid micromethod for the quantitative analysis of jojoba wax and its components

A method for the routine determination of jojoba wax ester composition and the ethanolysis products of these esters is described. In the recommended procedure, single or half seeds are crushed onto filter paper disks to provide duplicate 10–20 mg samples of the wax. One paper is extracted with petroleum ether for wax ester analysis and the second sample is transesterified in a sealed bottle using 5% HCl in ethanol at 80 C for 1–2 hr. This preparation is extracted with NaCl and petroleum ether, neutralized with potassium bicarbonate and dried with anhydrous sodium sulfate. The fatty acid ethyl esters and free alcohols are determined by gas chromatography (GC). The method requires only small amounts of seed material, provides duplicate samples of the wax, simplifies the ethanolysis procedures and reduces the time needed for the removal of the acid catalyst.     

Sugar fatty acid ester surfactants: Biodegradation pathways

In previous work, we found that the presence of a sulfonyl or alkyl group adjacent to the ester bond of sugar ester surfactants is associated with a dramatic reduction in the rate of biodegradation relative to that of unsubstituted esters. In this study, we investigated the pathways followed during the biodegradation of sucrose laurate, sucrose α-sulfonyl laurate, and sucrose α-ethyl laurate to determine the reasons for their different biodegradation rates. Through the use of high-performance liquid chromatography and proton nuclear magnetic resonance spectroscopy, the nature of the intermediates formed during the biodegradation of these three key sugar esters was determined. It was found that sucrose laurate biodegradation occurs via initial ester hydrolysis. In contrast, sucrose α-sulfonyl laurate degrades by initial alkyl chain oxidation. This indicates that the ester hydrolysis pathway is blocked by the sulfonyl group adjacent to the ester bond so that biodegradation is forced to proceed via the slower alkyl chain oxidation pathway. Sucrose α-ethyl laurate was degraded at least in part by alkyl chain oxidation, indicating that ester hydrolysis was also inhibited by the presence of an ethyl group. It is therefore concluded that previously observed relationships between structure and biodegradability arise because of the influence that different structural elements have on the pathways followed during biodegradation.     

蔗糖酯表面活性剂化学合成工艺研究进展

蔗糖酯表面活性剂作为一种广受关注的生物基表面活性剂,大量应用于食品、医药和化妆品等领域。当前,蔗糖酯的合成主要采用直接酯化、酰氯酯化和酯交换法进行,其中酯交换法是最常用的方法,然而蔗糖与甲酯相容性差导致其存在蔗糖焦化结块、甲酯水解和皂化等副反应,严重影响反应效率和产品性能。基于此,该文对溶剂法、微乳化法和无溶剂法等蔗糖酯合成工艺进行了介绍,随后,着重介绍了相转移催化剂、固体碱催化剂、离子液体等新型催化技术和物理界面强化技术在蔗糖酯合成中的应用。同时,对高效固体碱催化剂设计和多过程耦合强化技术在蔗糖酯合成中的应用及其反应机制的研究进行了展望,以期为蔗糖酯的合成技术的发展提供技术指导。     

蔗糖脂肪酸酯合成新技术

蔗糖脂肪酸酯是一种国际上公认的食品添加剂,具有广泛的应用范围。蔗糖脂肪酸酯的合成路线及工艺随着人们对产品要求的提高不断改进。中科院上海有机化学所采用了生物表面活性剂作为均相催化剂,并用无溶剂法合成了蔗糖酯,使蔗糖酯的合成达到了国际先进水平。     

Development of steryl ester analysis for the detection of admixtures of vegetable oils

The steryl ester content and composition of 28 samples from 10 vegetable oil types have been determined by isolation of the steryl esters by high-performance liquid chromatography and analysis by gas chromatography. The oils can be classified into oils with a high content (>4000 mg/kg) of steryl esters (corn and rapeseed); oils with a medium content (1400–2400 mg/kg) of steryl esters (sunflower oil and high-oleic sunflower oil); and oils with a low content (<1200 mg/kg) of steryl esters (safflower, soybean, cottonseed, groundnut, olive, and palm oils). The composition of the steryl ester fraction varies to a greater extent for different oil types than for different varieties of the same oilseed. The developed method is promising for authentication of some oils, and is particularly suitable for detecting admixtures of low levels of corn or rapeseed oils.     

High performance liquid chromatographic separation of sucrose fatty acid esters

The synthesis of sucrose fatty acid esters always results in complex mixtures. Two procedures for quantitative analysis of sucrose monoesters, respectively sucrose diesters, by means of high performance liquid chromatography on reversed-phase columns, are described. A mixture of methanol and water (85:15, v/v) was used for the separation of the monoesters, while methanol, ethyl acetate and water (65:25:10, v/v/v) was used for the separation of diesters. These methods gave information about the amount of monoesters and diesters in the product; the ratio between sucrose monopalmitate and sucrose monostearate, and the number of the most important structure isomers. A complete separation of all the possible diester products seemed to be impossible, due to the presence of more complex structure isomers. The described procedures can give important support during preparative work on sucrose fatty acid esters and also in the evaluation of these products for application purposes.     

Influence of solvent on degree of acylation in the formation of sucrose esters

Sucrose palmitates were prepared by the interesterification of sucrose and methyl palmitate in different solvents. The ratio of methyl palmitate to sucrose in dimethylformamide (DMF) solution was varied so that the effect on yield and ester composition could be evaluated. When sucrose esters were prepared in DMF, the palmitoyl groups approximated a random distribution when only penta- and lower esters were formed. When the proportion of palmitoyl groups was increased, hexa- through octaesters were formed, but the yield was less than that calculated for a random distribution. The interesterification of sucrose and methyl palmitate in solvents other than DMF, but under otherwise identical reaction conditions, yielded different reaction products. Only traces of sucrose esters were produced in hexamethylphosphoramide and formylmorpholine. Reactions in dimethylsulfoxide and N-methyl-2-pyrrolidinone yielded larger percentages of higher esters than were obtained in DMF. However the distribution was far from random. Presented at the AOCS Meeting, New Orleans, April 1970. S. Market. Nutr. Res. Div., ARS, USDA.     

Novel biobased dual-cure coating system

Sucrose esters consisting of acetoacetates and fatty acids were invented as novel biobased amine-cured and autoxidation dual-cure coating systems, in the presence of diamine crosslinker and metal salt driers. Acetoacetylated sucrose soyate (ASS) was an intramolecular system containing both acetoacetates and fatty acids in the same molecule. Miscible bicomponent blends, made of ASS and partially enamine alkyl substituted acetoacetylated sucrose (p-EAS), was an intermolecular curing system. Compatibility between the two components was achieved by reacting acetoacetylated sucrose (AS) with alkyl amines, in which the compatibility could be adjusted by either the alkyl chain length or the degree of enamine alkyl substitution, DES. Sucrose esters were characterized by gel permeation chromatography (GPC), Fourier transform infrared (FTIR) spectroscopy, nuclear magnetic resonance (NMR) spectroscopy, and differential scanning calorimetry (DSC). The properties and drying times of coatings cured through autoxidation, amine-acetoacetate reactions, and by dual-curing were studied. It was found that acetoacetate chemistry improved the attributes of sucrose ester of fatty acids in ambient curing conditions, as well as providing dual-cure coatings having a good balance of properties.     

Displacement of the double bonds during hydrogenation of unsaturated fatty acid methyl esters

Summary The displacement of the double bond of several unsaturated fatty acid methyl esters during hydrogenation with a nickel-kieselguhr catalyst at 180°C. was investigated. The analysis of the dicarboxylic acids (obtained by oxidation of the reaction products with KMnO₄ in acetic acid solution) by means of partition chromatography enabled a reliable semiquantitative determination of the position isomers formed. During hydrogenation of methyl esters of oleic, elaidic, petroselinic, and linoleic acid formation of large amounts of position isomers was proved to occur. Migration of the double bonds in both directions took place but was in all cases strongly pronounced in a direction opposite the ester group. The place and configuration (cis or trans) of the double bonds in the starting material apparently were of little importance in this respect. It follows that hydrogenation of fatty acid esters leads to products which are far more complicated, as is generally known. This is especially of importance with respect to the application of hydrogenated fatty oils in the food industries.     

Lipase-Catalyzed Synthesis of Fatty Acid Pyridylcarbinol Ester for the Analysis of Seed Lipids

Numerous derivatives of fatty acids (FA), including esters of methanol/3‐hydroxymethylpyridine or dimethyloxazoline, are used for the analysis of FAs in biological specimens. Picolinyl derivatives are frequently prepared for structural determination by gas chromatography–mass spectrometry (GC‐MS) since they provide characteristic fragments. The ester can be prepared by chemical methods‐multistep methodologies or basic transesterification. Microbial lipases catalyze a number of transesterification reactions, and their catalytic activities are often stable at extreme conditions. Although these characteristic features may be useful in the application of typical FA structure analysis by picolinyl ester, detailed studies have not been reported. To address the problems, a simple and quantitative methodology for the synthesis of picolinyl esters from lipids has been developed. It involves the transesterification with Novozym 435 (Novozymes Biopharma US Inc., Franklinton, USA), resin‐immobilized lipase from Candida antartica in toluene. Mild reaction conditions allow for complete derivatization of perilla seed oil in 30 min at 50 °C. The procedure was further studied with various TAGs and fatty wax from 17 plants. The optimized procedure was as follows; 1 mg lipid and 20 mg catalyst in 2 mL toluene at 50 °C for 1 h. Quantitative analysis of marker FAs was performed with the proposed method. The results coincided well with those from potassium t‐butoxide‐catalyzed reaction. The optimized method, however, was not applicable for the determination of some epoxy FAs, fatty wax, and parinaric acid.     

Preparation of sucrose esters by interesterification

Reactions between sucrose and esters of long chain fatty acids customarily have been conducted in a mutual solvent, such as dimethylformamide. The solvent-free interesterification of molten sucrose and fatty acid esters at temperatures between 170–187 C has now been performed with the aid of lithium, sodium and potassium soaps as catalysts and solubilizers. When the reactants were heated rapidly and then subjected to reduced pressure, the interesterifications could be brought to equilibrium in 12 min or less, including the time necessary to melt the sucrose. The several soaps and combinations of soaps employed differed markedly in their performance. No sucrose esters were obtained with lithium palmitate, while the yield with lithium oleate was among the best, but consisted of over 90% tetra- and higher esters of sucrose. Lower esters were best produced with combinations of lithium oleate with sodium or potassium oleate employed at a level of about 25% total soaps, based on the weight of sucrose. The type of fatty acid ester employed also markedly affected the yield of sucrose esters. Among the esters tested, methyl carbitol palmitate (which could be formed in situ), monopalmitin, distearin and technical grade diglycerides (48% diglycerides) prepared from completely hydrogenated cottonseed oil, interesterified readily. Presented at the AOCS Meeting, Minneapolis, October 1969. So. Utiliz. Res. Dev. Div., ARS, USDA.     

Volatile products from mild oxidation of methyl linoleate. Analysis by combined mass spectrometry-gas chromatography

The volatile products from autoxidation of methyl linoleate have been analyzed by combined mass spectrometry-gas chromatography. The principal components were pentanal, hexanal, amyl formate, methyl octanoate, and substituted dioxolanes. Minor components included esters, alcohols, ketones, aldehydes, hydrocarbons, and acetals. Certain unsaturated carbonyl compounds, previously reported, were not detected. A laboratory of the W. Utiliz. Res. Devel. Div., ARS, USDA.