非离子表面活性剂棕榈酸异丙酯的合成研究

棕榈酸异丙酯(IPP)是一种低粘度亲油类的非离子型表面活性剂,大量用于护肤霜和蜜类化妆品中.它的合成方法主要有4种[1,2]:1.在磺酸型离子交换树脂存在下,丙烯与棕榈酸并流通过反应床.2.以沸石负载锌作催化剂,在2758 kPa压力下,棕榈酸同丙烯快速合成棕榈酸异丙酯.3.以棕榈酸、异丙醇为反应物,直接酯化合成棕榈酸异丙酯.4.以含棕榈酸的油脂为原料(如椰子油或棕榈油),与过量的甲醇在常压下、催化剂存在下进行醇解反应,再经进一步酯交换、分馏制得.棕榈油是天然可再生资源,利用棕榈油提取得到的棕榈酸天然、安全、可靠.本文以棕榈油为原料,从中提取棕榈酸,再以棕榈酸、异丙醇为反应物,以改性氧化锆或SO42-/ZrO2固体超强酸作为催化剂直接酯化合成棕榈酸异丙酯.得到了直接酯化法合成棕榈酸异丙酯的最佳工艺参数.收率在90%以上,棕榈酸异丙酯纯度达98.6%.     

The effects of dietary fish oil on alveolar type II cell fatty acids and lung surfactant phospholipids

The purpose of this study was to determine the responsiveness of alveolar type II cells to dietary fish oil and the consequent effects on alveolar and lung surfactant. Rats were fed a corn oil or a fish oil diet for four weeks. Dietary n−3 fatty acids were readily incorporated into the type II cell phospholipids as indicated by higher levels of eicosapentaenoic acid (2.77±0.10%) and docosahexaenoic acid (1.63±0.10%) in the group receiving the fish oil diet. The elevated levels of n−3 fatty acids were accompanied by concomitant reduction in arachidonic acid and linoleic acid. Neither eicosapentaenoic acid nor docosahexaenoic acid was incorporated into type II cell triacylglycerols. Feeding a fish oil containing diet increased surfactant phospholipids, particularly 1,2-disaturated acyl phosphatidylcholines in whole lung compared to a corn oil diet. However, the amount of surfactant found in the alveolus was not different between the two diet treatment groups. The results suggest that dietary n−3 fatty acids stimulate synthesis and/or inhibit degradation of lung surfactant without altering surfactant secretion in alveoli.     

Fatty acid composition of lung,macrophage and surfactant phospholipids after short-term enteral feeding with n−3 lipids

Utilization of enteral feeding modalities may prove clinically relevant for rapid modulation of lung phospholipid polyunsaturated fatty acids (PUFA) that serve as substrates for the formation of vasoactive dienoic eicosanoids. We compared the effects of short-term enteral feeding with formulations enriched with either fish (n−3) or corn (n−6) oil PUFA on the fatty acid composition of rat lung, alveolar macrophage and surfactant phospholipids. The diets were infused continuously for 72 h through a surgically placed gastroduodenal feeding catheter by a syringe pump. The n−3 PUFA derived from the fish oil enriched diet were readily incorporated into the phospholipid membranes of the alveolar macrophages, lung tissue and pulmonary surfactant. The relative percentages of the n−3 PUFA were significantly higher and individual and total n−6 PUFA significantly lower in the macrophage, lung and surfactant phospholipids from the n−3-supplemented rats in comparison with those present in the rats infused enterally with the n−6 diet or untreated, chow-fed rats (baseline). In contrast, there was a significant increase in linoleic acid (18∶2n−6) without modification of arachidonic acid (20∶4n−6) in the alveolar macrophages, lung tissue and surfactant from rats enterally receiving the n−6 diet relative to levels measured in the rats at baseline. The results suggest that short-term continuous delivery of n−3-enriched enteral preparations can foster rapid modification of membrane phospholipid PUFA composition of lung tissue, alveolar macrophages and lung surfactant. Utilization of similar infusion modalities to deliver n−3-enriched enteral formulations may prove beneficial to critically ill or postoperative patients with persistent lung inflammation secondary to uncontrolled formation of vasoactive eicosanoids derived from arachidonic acid.     

Accumulation of surfactant phospholipids in lipid pneumonia induced with methylnaphthalene

Lipid analyses were carried out on the lungs of female B₆C₃F₁ mice treated with methylnaphthalene. Cholesteryl ester, which could not be detected in lungs of control animals, was present in lungs of treated animals. Cholesterol and dipalmitoyglycerophosphocholine (DPPC) content was increased about five times in lungs of treated mice compared with control mice, and the content of a minor phospholipid was increased six times. The latter phospholipid was purified by high performance liquid chromatography and identified as phosphatidylglycerol by thin layer chromatography and by fast atom bombardment-mass spectrometry. Both DPPC and phosphatidylglycerol are known to be pneumonal surfactants produced from type II pneumocytes. Therefore, the accumulation of these lipids in lung tissue was assumed to be caused by the proliferation of type II cells induced by the administration of methylnaphthalene. The results provide important information concerning the underlying mechanism of endogenous lipid pneumonia in mice.     

Desaturation of endogenous and exogenous palmitate in lung tissue in vitro

Lung slices from rats fed a fat-free diet supplemented with safflower oil (control) or tripalmitoyl-glycerol (essential fatty acid [EFA]-deficient) were incubated with [¹⁴C] acetate, [¹⁴C] palmitate, or [¹⁴C] stearate. Of the¹⁴C recovered in phospholipids after incubation with [¹⁴C] acetate, more than 87% was in 16-carbon fatty acids. Desaturation, as assayed by the percentage of radioactivity in monoenoates in phospholipid fatty acids, was generally double in EFA-deficient slices compared to control slices, regardless of substrate. Desaturation was significantly greater in slices incubated with acetate or octanoate compared to palmitate, indicating that endogenously synthesized palmitate was desaturated more actively than that derived from an exogenous source. Presented in part to the American Physiological Society, Toronto, Canada, October 1980, and published in abstract form inPhysiologist (1980) 23, 135.     

Characteristics of phospholipids in human lung carcinoma

Human lung carcinoma tissues with histological types of adenocarcinoma, squamous cell and small cell carcinoma were investigated for phospholipids. There were marked differences in the phospholipids between these lung carcinoma and normal lung tissue. A marked decrease in saturated phosphatidylcholine (PC), predominantly the dipalmitoyl species, was noted in the carcinoma, although they still contained 17–20% of the saturated classes. The lung carcinoma contained less phosphatidylglycerol (PG) and lyso-bis-phosphatidic acid and more cardiolipin and phosphatidylinositol (PI) than the normal lung tissue. These alterations observed in the lung carcinoma apppeared to show that they lose the characteristic feature of phospholipids in the lung tissue. The differences in the lipid composition among different cell types of lung carcinoma were also noted. The squamous cell and small cell carcinoma contained more triacylglycerol and relatively higher dienes I (monoenoic-monoenoic) and lower dienes II (saturated-dienoic) of PG, respectively, as compared to adenocarcinoma.     

The phospholipid composition of pig lung surfactant

Surface active material (surfactant), which contained 80% lipid material, was isolated from pig lungs by the saline perfusion procedure. The lipids were analyzed by column, thin layer and paper chromatography, followed by gas liquid chromatography to determine the fatty acid composition of the major phospholipid fractions. It was found that this pig lung surfactant contained the phospholipid constituents known to be present in mammalian tissues and in addition, phosphatidylglycerol (1.5%) and lyso-bisphosphatidic acid (2.0%) were also found. These two components occurred in higher proportions in the surfactant lipids than in the lipids of the whole lung tissues.     

The phospholipids of rabbit type II alveolar epithelial cells: Comparison with lung lavage,lung tissue,alveolar macrophages,and a human alveolar tumor cell line

The phospholipid composition of type II alveolar epithelial cells from the rabbit was compared with that of alveolar macrophages, lung lavage and lung tissue. In addition, the phospholipid composition of a human alveolar tumor cell line, which is morphologically similar to type II cells, was examined. Phosphatidylcholine accounted for 48% of the total phospholipid in the type II cells, 41% in the tumor cells, and 30% in the macrophages. Phosphatidylcholine was 51% disaturated in the type II cells, 54% in lung lavage, 39% in whole lung, 29% in lavaged lung and macrophages, and 16% in the tumor cells. Palmitic acid was the major fatty acid in phosphatidylcholine from all samples with the exception of the tumor cells in which almost half of the fatty acids were accounted for by oleic acid. The phospholipids of the type II cells were more similar to those of lung lavage, and thus surfactant, than to lung tissue and macrophages. This is consistent with their supposed role in surfactant production. The tumor cells, although morphologically similar to type II cells, were quite different with respect to phospholipid composition.     

Substrate metabolism in the perfused lung: Response to changes in circulating glucose and palmitate levels

The effects of circulating levels of glucose and palmitate in the isolated perfused rat lung were investigated. Rat lungs were perfused for 1.5 hr with washed bovine erythrocytes (15% hematocrit) in Krebs-Henseleit bicarbonate buffer containing 5 g% bovine serum albumin. Glucose uptake in the perfused lung varied directly with circulating glucose concentration. Lactate production was affected proportionately more by high glucose levels than by low concentrations. Pyruvate production was decreased by both low glucose and palmitate concentration in the circulating medium. Oxidation of glucose to CO₂ was depressed by low glucose and by high palmitate concentrations. Glucose incorporation into lung lipids was more strongly influenced by glucose concentration than by circulating palmitate levels. These data indicate acute changes in circulating levels of glucose and palmitate alone can act to either inhibit or stimulate glycolysis, glucose oxidation, and lipid synthesis in the perfused lung. This investigation was supported by NIH grants HL 16528 and HL 16247. RAR is supported by Research Career Development Award K04 HL 00166 from the National Heart and Lung Institute.     

Effect of surfactant and electron treatment on the electrical and thermal conductivity as well as thermal and mechanical properties of ethylene vinyl acetate/expanded graphite composites

This study presents an investigation of the electrical and thermal conductivities of composites based on an ethylene vinyl acetate (EVA) copolymer matrix and nanostructured expanded graphite (EG). To improve the EG dispersion in EVA, EG sheets were modified by treating them with the anionic surfactant sodium dodecyl sulphate (SDS) in water. The modified SDS‐EG platelets, after being filtered and dried, were melt‐mixed with EVA to prepare the composites. Finally, both EVA/EG and EVA/SDS‐EG composites were subjected to 50 kGy electron beam (EB) irradiation. SEM images confirm that the irradiated EVA/EG samples had improved interfacial adhesion, while the irradiated EVA/SDS‐EG samples showed even better interfacial adhesion. The gel contents of the irradiated samples without and with SDS treatment increased with increase in EG loading. The EVA/EG composites exhibited a sharp transition from an insulator to a conductor at an electrical percolation threshold of 8 wt %, but with SDS‐EG the electrical conductivity was extremely low, showing no percolation up to 10 wt % of filler. The EB irradiation had no influence on electrical conductivity. The thermal conductivity linearly increased with EG content, and this increase was more pronounced in the case of SDS‐EG, but decreased after EB irradiation. The thermal properties were little influenced by EB irradiation, while better polymer–filler interaction and better filler dispersion as a result of SDS treatment, and the EB irradiation initiated formation of a cross‐linked network, had a positive effect on the tensile properties. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42396.     

复配表面活性剂水溶液吸收法处理乙酸丁酯废气

以非离子型表面活性剂为吸收剂吸收乙酸丁酯废气,研究了不同类型的Tween表面活性剂和Span-80对乙酸丁酯废气的吸收效果,并以复配表面活性剂为吸收剂分析了吸收剂温度、液气比、进塔浓度对乙酸丁酯废气吸收率的影响。结果表明,Tween-80水溶液对乙酸丁酯吸收率最高,加入Span-80后不但能够消除起泡现象还能提高乙酸丁酯吸收率,其加入量越大吸收率越大。以体积浓度3.0%的Tween-80与3.0%的Span-80复配水溶液吸收乙酸丁酯废气,在吸收剂温度为10℃,进塔废气流量为1.0 m~3/h,液气比为15 L/m~3时,乙酸丁酯吸收率可达90.65%。吸收剂在解吸后循环使用,其吸收率为81.21%,且随着解吸次数的增加吸收率略有降低。     

复配表面活性剂水溶液吸收法处理乙酸丁酯废气

以非离子型表面活性剂为吸收剂吸收乙酸丁酯废气,研究了不同类型的Tween表面活性剂和Span-80对乙酸丁酯废气的吸收效果,并以复配表面活性剂为吸收剂分析了吸收剂温度、液气比、进塔浓度对乙酸丁酯废气吸收率的影响。结果表明,Tween-80水溶液对乙酸丁酯吸收率最高,加入Span-80后不但能够消除起泡现象还能提高乙酸丁酯吸收率,其加入量越大吸收率越大。以体积浓度3.0%的Tween-80与3.0%的Span-80复配水溶液吸收乙酸丁酯废气,在吸收剂温度为10℃,进塔废气流量为1.0 m³/h,液气比为15 L/m3/h,液气比为15 L/m³时,乙酸丁酯吸收率可达90.65%。吸收剂在解吸后循环使用,其吸收率为81.21%,且随着解吸次数的增加吸收率略有降低。     

氨基磺酸催化合成棕榈酸异辛酯

在减压条件下以氨基磺酸为催化剂合成了棕榈酸异辛酯。探讨了原料配比、催化剂用量、反应时间、反应温度等因素对酯化率的影响。确定了最佳工艺条件,并考察了催化剂重复使用效果。     

Incorporation of [1-14C] acetate into phospholipids by soybean seedlings

Incorporation of [1-¹⁴C] acetate into lipids by slices of soybean seedlings was studied. The results were as follows: (a) the greatest amount of radioactivity was detected in the phospholipid fraction prepared from the main axis; (b) in the cotyledons, radioactivity was about the same in pigment, phosphatidylethanolamine, and phosphatidylglycerol; (c) phosphatidylcholine was the main phospholipid labeled in the axis; (d) the distribution of radioactive fatty acids in the axis suggested that this tissue has the capacity for both phospholipid synthesis and fatty acid desaturation.     

Antioxidant activity and active sites of phospholipids as antioxidants

Various compounds, representative of the major functional groups in phospholipids, phosphatidylethanolamine and phosphatidylcholine, were tested for antioxidant activity (AA) in a sardine oil system to determine the relationship between molecular structure and the AA of these compounds. AA was found to be attributable not only to the side-chain amino groups but also to the cooperative effect of the hydroxy group in the side chain. Choline and ethanolamine, side-chain moieties of phospholipids, strongly inhibited increases in peroxide values in a sardine oil mixture during storage; however, phosphatidic acid derivatives and glycerol, also major functional groups of phospholipids, did not show AA. Choline and ethanolamine have hydroxy amines as functional groups; therefore, several model reagents that contained amines and alcohols were assayed to compare the activity of the amino group with that of the hydroxy group. All basic alkylamines examined had AA as decomposers of hydroperoxides. The intramolecular hydroxy group in these amines complemented AA of the amino group. Only intramolecular alcohol, which can donate a proton, showed strong synergistic activity with AAof the basic amines, while protected groups, such as methyl ether and phosphate ester, did not show this effect.     

Comparison of free α-tocopherol and α-tocopheryl acetate as sources of vitamin E in rats and humans

The uptake of α-tocopherol from 2R,4′R,8′R-α-tocopherol and 2R,4′R,8′R-α-tocopheryl acetate has been compared in rats and humans. The two forms of vitamin E were compared simultaneously in each subject (rat and human) by using a combination of deuterium-substitution and gas chromatography-mass spectrometry (GC-MS) to distinguish and measure the competitive uptake of α-tocopherol from an orally ingested mixture of the acetate and the free phenol forms. When rats were dosed in a manner analogous to that used in traditional bioassays, i.e., providing the two forms of vitamin E one daily in tocopherol-stripped corn oil for four successive days immediately prior to sacrifice, the net uptake of α-tocopherol from the free phenol form was only half that from the acetate. This result is consistent with the greater activity of the acetate that had been observed previously in bioassays. However, when the two forms of tocopherol were intubated into rats as a single dose mixed in with an aqueous bolus of standard laboratory diet, the amount of α-tocopherol taken up from the free form after 24 hr was very similar to that derived from the acetate. In five adult humans, competitive uptake studies of the two forms after a single dose taken with a meal showed that the amount of α-tocopherol from the free phenol form was equal to that from the acetate in plasma and red blood cells. These findings illustrate the value and potential of using deuterium-substituted α-tocopherol and GC-MS in evaluating the effectiveness of different forms of vitamin E in human studies. The results also stress the need for caution in using data obtained from animal bioassays when considering comparative human nutritional standards.     

Synthesis of phospholipids and phospholipid fatty acids by isolated perfused rat lung

Synthesis of phospholipids and phospholipid fatty acids in isolated perfused rat lung was studied. The perfusion fluid was a Krebs-Ringer bicarbonate buffer containing a¹⁴C labeled substrate. It was found that 1-¹⁴C-acetate, 1-¹⁴C-laurate, 1-¹⁴C-palmitate, 1-¹⁴C-stearate, 1-¹⁴C-oleate, or U-¹⁴C-D-glucose was incorporated into tissue lipids in the isolated perfused lung at a rate geeater than that in incubated minced tissue. However, the patterns of the newly synthesized lipids from these two systems were similar. In 1 hr of perfusion, 6.8, 3, 14.5, 7.5, 7, and 2% of the initial¹⁴C-radioactivity of 1-¹⁴C-acetate, 1-¹⁴C-laurate, 1-¹⁴C-palmitate, 1-¹⁴C-stearate, 1-¹⁴C-oleate, and U-¹⁴C-D-glucose, respectively, were incorporated into phospholipids. Phospholipid fatty acids accounted for 95–96% total phospholipids-¹⁴C when¹⁴C-substrates, other than glucose, were used. For glucose, only 20% phospholipids-¹⁴C was in phospholipid fatty acids. More than 80% phospholipid fatty acids-¹⁴C was in palmitic acid when 1-¹⁴C-acetate and U-¹⁴C-D-glucose were used, while 37, 61, 80, and 94% phospholipid fatty acid-¹⁴C from 1-¹⁴C-laurate, 1-¹⁴C-sterate, 1-¹⁴C-oleate, and 1-¹⁴C-palmitate, respectively were recovered in the original form of the fatty acid used. The newly synthesized phospholipid fatty acid (13–24%) from 1-¹⁴C-laurate, 1-¹⁴C-stearate, and 1-¹⁴C-oleate was palmitic, and 10% of phospholipid fatty acid from 1-¹⁴C-stearate was in oleic acid. Hydrolysis by phospholipase A showed that¹⁴C from perfused substrates was esterified to both α and β positions of phospholipids. It was found that positional selectivity of phospholipid fatty acids was determined by chain length, degree of unsaturation, and source of fatty acid.     

Regulation of lung surfactant cholesterol metabolism by serum lipoproteins

The isolated perfused rat lung was used as an experimental model in the study of the lipoprotein regulation of surfactant cholesterol metabolism. Addition of low density lipoproteins (LDL) to the perfusion medium at a cholesterol concentration of 0.5 mM had no inhibitory effect on [1-¹⁴C]-acetate incorporation into cholesterol of either the surfactant or residual fractions. Increasing the concentration of cholesterol in the medium to 2.5 mM resulted in significant inhibition of incorporation into cholesterol of both fractions. A similar inhibition resulted when lungs were perfused with 2.5 mM cholesterol in the form of high density lipoproteins (HDL). No inhibition of fatty acid synthesis, measured as incorporation into cholesteryl esters, was observed. The rate of uptake by perfused lung of cholesterol from both high and low density lipoproteins was similar. Competitive binding studies with¹²⁵I-labeled lipoproteins indicated the existence of lung receptors for both classes of lipoprotein. The rate of uptake of the apoprotein moiety of low density lipoproteins was significantly greater than that of high density lipoproteins. These data suggest that lung cholesterol metabolism may be subject to regulation by both low and high density serum lipoproteins.     

表面活性剂检测方法ISO标准与国内标准的比较和讨论

国际标准化组织负责目前绝大部分领域的标准化活动,我国也积极将ISO标准进行转化。由于国情和部分历史原因,尚有少部分ISO标准尚未转化。针对这一情况进行分析和讨论,介绍了我国对ISO标准的转化情况,针对其中部分标准的转化问题进行详细分析并总结了相关原因。