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1.
Daniel Swern A. J. Stirton J. Turer P. A. Wells 《Journal of the American Oil Chemists' Society》1943,20(11):224-226
Summary Fat-soluble fatty acid monoesters of 1-ascorbic acid (vitamin C) and d-isoascorbic acid have been prepared from lauric, myristic,
palmitic, and stearic acids in 40–50 per cent yields.
Evidence has been presented to show that only the primary hydroxyl group of each of the ascorbic acids has been esterified.
Antioxidant properties of these esters are being studied.
Preliminary tests on the esters have indicated that they may have useful properties as interfacial modifiers. 相似文献
2.
This study reports the electrohydrodimerization of pyruvic acid to 2,3-dimethyltartaric acid in sulphuric acid medium (0.5 M H2SO4) on a lead cathode. The main products detected were lactic acid and 2,3-dimethyltartaric acid. The selectivity towards the formation of 2,3-dimethyltartaric acid was studied vs. pyruvic acid concentration in sulphuric acid solution, at −1.1 V vs. MSE. The best selectivity of 2,3-dimethyltartaric acid reached 69% for an initial concentration of 1.7 M pyruvic acid. The yield of pyruvic acid was 84%. 相似文献
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Shigenobu Kishino Jun Ogawa Yoriko Omura Kenji Matsumura Sakayu Shimizu 《Journal of the American Oil Chemists' Society》2002,79(2):159-163
After screening 14 genera of lactic acid bacteria, Lactobacillus plantarum AKU 1009a was selected as a potential strain for CLA production from linoleic acid. Washed cells of L. plantarum with high levels of CLA production were obtained by cultivation in a nutrient medium with 0.06% (wt/vol) linoleic acid (cis-9,cis-12-octadecadienoic acid). Under the optimal reaction conditions with the free form of linoleic acid as the substrate, washed
cells of L. plantarum produced 40 mg CLA/mL reaction mixture (33% molar yield) from 12% (wt/vol) linoleic acid in 108 h. The resulting CLA was
a mixture of two CLA isomers, cis-9,trans-11 (or trans-9,cis-11)-octadecadienoic acid (CLA1, 38% of total CLA) and trans-9,trans-11-octadecadienoic acid (CLA2, 62% of total CLA), and accounted for 50% of the total FA obtained. A higher yield (80% molar
yield to linoleic acid) was attained with 2.6% (wt/vol) linoleic acid as the substrate in 96 h, resulting in CLA production
of 20 mg/mL reaction mixture [consisting of CLA1 (2%) and CLA2 (98%)] and accounting for 80% of total FA obtained. Most of
the CLA produced was associated with the cells (ca. 380 mg CLA/g dry cells), mainly as FFA. 相似文献
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以正丁醇为内标,氢火焰离子化检测器测定,建立了气相色谱法直接进样测定乳酸催化制备丙烯酸反应液中乳酸和丙烯酸含量的方法。在载气(N2)流速为30mL·min^-1,氢气流速为88mL·min^-1,空气流速为300mL·min^-1,进样器和离子室温度为160℃,柱温为150℃的10%PEG-20M(3m×3mml填充柱上能实现很好的分离。乳酸和丙烯酸测定方法的线性相关系数分别为0.9994和0.9996,相对标准偏差分别为O.74%和0.56%,平均回收率分别为97.35%-1197.60%,检出限分别为8.62mg·L^-1和1.21mg·L^-1方法简便、快速、准确。 相似文献
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开发研究了氯乙酸副产盐酸的精制工艺及盐酸中有机杂质的紫外分光光度分析方法。副产盐酸经酸洗、吸收、蒸馏得高纯盐酸。中试结果表明 ,工艺合理 ,精制盐酸达到GB 32 0 - 93规定的工业用合成盐酸标准 相似文献
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介绍炼厂酸性气制硫酸装置的工艺过程。由于实供气源与设计值有较大出入,二氧化碳浓度偏高, 并且夹带烃类物质较多,使装置无法正常运行。通过对酸性气进行预处理后,一次开车成功,各项工艺指标均达到设计要求,遇酸性气流量突降时可补充适量硫磺,维持正常生产。 相似文献
8.
Edwin S. Olson 《Journal of the American Oil Chemists' Society》1977,54(2):51-53
The performic acid oxidation of linoleic acid has been shown to form 9,12-dihydroxy-trans-10,11-methylene-heptadecanoic acid (I) after hydrolysis of the formate ester. A sequence of reactions led to the identification of dimethyl-trans-1,2-cyclopropanedicarboxylate by gas liquid chromatography. Spectroscopic evidence is presented for thetrans geometry in I. Failure of the monoepoxide of linoleic acid to give the formate ester of I suggests the alternative that a homoallylic carbonium ion is formed directly upon attack of the peroxide reagent. 相似文献
9.
Dr. J. R. Ochoa 《Journal of Applied Electrochemistry》1993,23(9):910-914
The electrosynthesis of iminodiacetic acid by electrooxidation of nitrilotriacetic acid in undivided cells has been studied using Zn, Cu, PbO2, DSA®O2, DSA®Cl2, C, Ni and porous carbon as anodes. Results show that the synthesis is possible in both acid and basic mediums. The best results were obtained in aqueous 40% w/w sulphuric acid with porous carbon RVC-4000 as anode and SUS 316 as cathode, at 60 °C, 400 mA cm-2 and charge 95% of theoretical. Under these conditions, nitrilotriacetic acid conversion was 92%, current efficiency 80% and selectivity 85%. Loss of selectivity was due to chemical side reaction between iminodiacetic acid and HCHO electrogenerated in the electrolysis. 相似文献
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Carroll KK 《Lipids》1966,1(3):171-175
1-14C-Oleic acid, 2-14C-erucic acid and 2-14C-nervonic acid were administered to rats by tail-vein and the distribution of radioactivity in liver lipids was determined
at intervals from 15 min to 6 hr after injection. High levels of activity were found after short time intervals which were
mainly associated with triglycerides in the case of oleic acid and with free fatty acids in the case of erucic acid and nervonic
acid. The activity in these lipids decreased with time and was later exceeded by that in more polar lipids. In rats given
erucic acid or nervonic acid, sphingolipids were more highly labelled than glycerophosphatides. Nervonic acid showed little
tendency to form a complex with serum albumin and erucic acid complexed less readily than palmitic acid.
Presented at the AOCS Meeting in Houston, April 1965. 相似文献
13.
在作者开发的高速反应器一步法制专用级次磷酸钠的基础上进一步将生成的次磷酸钠和副产的亚磷酸氢钙用离子膜电渗析法制成纯度更高的次磷酸及亚磷酸产品,产品质量升级,回收利用了副产亚磷酸氢钙,并减少了原料烧碱的用量。该新工艺成本低,能耗小,无三废排出,产品多样化,属循环经济、环境友好新工艺。 相似文献
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Dmytro Buchnea 《Lipids》1974,9(1):55-57
Chromatography on silicic acid-boric acid columns permits detritylation of ester lipids, essentially without acyl migration,
and simultaneous separation of the reaction products. Described is the preparation of the column and its application for the
synthesis of diacyl-sn-glycerols and 2-acyl-1,2-propaneiols.
Presented in part at the Canadian Federation of Biological Societies Annual Meeting in Toronto, June 1971. 相似文献
16.
研究连续草酸电解还原制备乙醛酸的过程和工艺。采用一膜两室电解面积为10cm×10cm的离子膜电解槽进行连续电解实验,比较了电极材料、阳离子交换膜材料、研究了电解液流量对电流效率的影响以及电流密度、电解温度和电解时间对电解过程的影响。结果表明以铅极板作阴极、钽-铱作阳极板、NF-1型含氟磺酸阳离子交换膜时电解的效果较好,得到的优化电解条件为:电流密度1000A.m-2,电解温度25℃,电解时间4.5h,阴极液和阳极液流量均为2L.min-1。在此条件下的电耗为3038.9kWh.t-1产品,研究结果可为工业化设计提供参考数据。 相似文献
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The effects of oleanolic acid (OA) and ursolic acid (UA) on the fluidity and stability of dipalmitoyl phosphatidylcholine
(DPPC) liposomal membrane were monitored by measuring the fluorescence polarization of 1,6-diphenyl-1,3,5-hexatriene labeled
in the liposomal membrane and the leakage of calcein from the probe-encapsulated liposomes. The experiments with the liposomes
made of DPPC and OA or UA showed that OA and UA exhibited a moderate fluidity-modulating effect for the liquid-crystalline
liposomal membrane, and a strong condensing effect for both crystalline and liquid-crystalline liposomal membranes. Their
effects were comparable to those of cholesterol. These results suggest that their fluidity-modulating and condensing effects
might have some implications in their biological functions. 相似文献
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