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去氢枞酸甲酯选择性硝化反应的研究 总被引:1,自引:0,他引:1
采用均匀设计方法深入研究了去氢枞酸甲酯在HNO3-Ac2O-AcOH体系中选择性硝化的反应条件.通过理论计算和实验验证获得去氢枞酸甲酯选择性硝化的较优反应条件如下:n(硝酸):n(去氢枞酸甲酯)为3:1、混合溶剂中乙酐与乙酸的体积比为7:1、反应温度为20℃、反应时间为60 min.此时12-硝基去氢枞酸甲酯和14-硝基去氢枞酸甲酯的总产率由50%提高到84.6%,其中12-硝基去氢枞酸甲酯的产率达到64.0%、14-硝基去氢枞酸甲酯的产率达到20.6%,二者的产率比约为3.1:1.12-硝基去氢枞酸甲酯的反应产率和选择性都明显高于文献报道值. 相似文献
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L-抗坏血酸硬脂酸酯的合成条件探索 总被引:1,自引:0,他引:1
文章对L-抗坏血酸硬脂酸酯的最佳合成条件进行探索。通过各种不同的实验条件得出最佳合成条件为:抗坏血酸比硬脂酸甲醣为1:1.3(摩尔比),催化剂浓硫酸比(抗坏血酸+硬脂酸甲酪)为1:0.10(摩尔比),反应温度24℃,反应时闯24h。在此条件下可获得总产率为77%的抗坏血酸硬脂酸酯。考察了以硬脂酸甲酯和L-抗坏血酸为原料,通过酯交换法合成L-抗坏血酸硬脂酸酯的最佳合成条件。文章对L-抗坏血酸硬脂酸酯的最佳合成条件进行探索。通过各种不同的实验条件得出最佳合成条件为:抗坏血酸比硬脂酸甲酯为1:1.3(摩尔比),催化剂浓硫酸比(抗坏血酸+硬脂酸甲酯)为1:0.10(摩尔比),反应温度24℃,反应时间24h。在此条件下可获得总产率为77%的抗坏血酸硬脂酸酯。考察了以硬脂酸甲酯和L-抗坏血酸为原料,通过酯交换法合成L-抗坏血酸硬脂酸酯的最佳合成条件。 相似文献
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非水相酶催化合成L-抗坏血酸棕榈酸酯 总被引:2,自引:0,他引:2
研究了不同脂肪酶在有机溶剂体系中催化合成L-抗坏血酸棕榈酸酯,确定了较有效的脂肪酶和溶剂体系,对影响产物浓度的几种主要因素进行了讨论,确定最适反应条件为叔丁醇为溶剂、催化剂Novozyme435脂肪酶的质量浓度10g·L-1、底物棕榈酸与Vc摩尔比3∶1、反应温度59℃和反应时间50h。纯化后产物的纯度可达95%。 相似文献
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以去氢枞酸为原料,经PCl3或SOCl2酰化得到去氢枞酰氯,与水合肼进行酰肼化反应得到N,N-二去氢枞酰基肼,再分别经过闭环和缩合反应得到目标化合物。研究了各化合物的反应条件;其中N,N-二去氢枞酰基肼的合成可在室温下完成,收率86.2%;合成2,5-双去氢枞基-1,3,4-噻二唑的最佳闭环剂是POCl3,在POCl3既做闭环剂又做溶剂的条件下,收率83.2%;2,5-双去氢枞基-1,3,4-噁二唑的合成中,在P2S5的作用下,以吡啶作为溶剂,收率可达到85.5%;整个合成路线中各步反应的收率都在80%以上,高收率得到目标化合物;其结构经IR、1HNMR和元素分析进行表征和确证。 相似文献
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在N,N-二甲基乙酰胺(DMAc)中,苯甲酸与SOCl2反应生成的苯甲酰氯不经分离,继续与L-抗坏血酸反应得到L-抗坏血酸苯甲酸酯。考察了酰氯化反应时间、成酯反应时间、反应溶剂和物料比对反应收率的影响,结果表明,以10mL DMAc为溶剂,0℃下酰氯化反应2h后,接着在25℃下成酯化反应10h,苯甲酸10mmol,n(苯甲酸)∶n(SOCl2)∶n(L-抗坏血酸)=1.0∶1.1∶1.6,反应收率为62.8%。产物结构经1 H NMR、13C NMR、MS和IR确认。 相似文献
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叔戊醇体系中酶法合成L-抗坏血酸脂肪酸酯的研究 总被引:4,自引:0,他引:4
研究以棕榈油为酰基供体和L-抗坏血酸在有机相中利用脂肪酶催化酯交换反应合成L-抗坏血酸脂肪酸酯.对催化合成L-抗坏血酸脂肪酸酯的反应介质进行了比较,系统考察了底物浓度、溶剂用量、底物摩尔比、温度、水活度、分子筛加入时间和加入量对酶催化反应的影响,确定了最适反应条件:在20 mL用分子筛充分除水的叔戊醇中,0.352g·... 相似文献
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我国脂肪酸的生产和应用 总被引:3,自引:0,他引:3
陆蠡珠 《精细与专用化学品》2007,15(1):24-28
简要介绍脂肪酸的分类、原料来源、生产工艺、品种以及用途。并对我国脂肪酸的生产现状进行了分析。重点介绍了脂肪酸在我国橡胶工业中、塑料助剂等领域的应用,脂肪酸甲酯作为表面活性剂在不同领域的广泛应用,最后还简述了癸二酸和改性醇酸树脂应用。 相似文献
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酸液体系的研究现状分析和现场应用 总被引:1,自引:0,他引:1
酸化解堵与压裂改造相比,它具有施工相对简单和成本相对较低等特点,所以酸化解堵是一项各油田广泛使用的油气田增产技术。酸化解堵技术已有将近100历史,现已研制出具有不同特点的酸液体系,如乳化酸、泡沫酸、固体酸、多氢酸等,基本能满足复杂地质条件对酸液的要求。 相似文献
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The Growth‐Inhibiting Effects of Beef Fatty Acids on MCF‐7 Cells Are Influenced Mostly by the Depot Location and Inconsistently by the Biohydrogenation Intermediate Content 下载免费PDF全文
Payam Vahmani David C. Rolland Katherine E. Gzyl Danica D. S. Baines Michael E. R. Dugan 《Lipids》2018,53(7):699-708
Biohydrogenation intermediates (BHI) including conjugated linoleic acid (CLA) isomers are formed during ruminal biohydrogenation of polyunsaturated fatty acids (PUFA) in ruminants. Although many studies have examined the anticarcinogenic effects of CLA, few studies have reported the anticarcinogenic properties of BHI in their natural form found in dairy and beef fats. The present study compared the growth‐inhibitory effects of fatty acids from beef perirenal fat (PRF) or subcutaneous fat (SCF) with low or high levels of BHI in MCF‐7 human breast cancer cells. Cells were exposed for 72 h to media containing increasing doses (50 to 400 μM) of different beef fat treatments. Fatty‐acid analysis showed that BHI were readily incorporated into cell phospholipids (PL) in a treatment‐dependent manner, but higher BHI in PL did not consistently inhibit growth. Culturing with low‐BHI PRF or high‐BHI PRF did not lead to growth inhibition, but low‐BHI SCF inhibited growth, and inhibition was further increased by high‐BHI SCF. Other classes of fatty acids may, therefore, be interacting with BHI resulting in differential effects on growth inhibition in human breast cancer cells. 相似文献
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介绍了磷钼杂多酸的合成。通过正交试验探讨了反应物料量比、三氧化钼浓度、反应温度和反应时间对产物产率的影响。结果表明,最适宜的反应条件为:反应物量比n(三氧化钼)∶n(磷酸)=12∶1.0、反应温度t=70℃、反应时间7 h、三氧化钼与水的质量比1∶8。经红外光谱分析及熔点测定确定所得产品为磷钼杂多酸化合物。并以磷钼杂多酸取代硫酸作催化剂制备乙酸乙醋来研究其催化活性,并与硫酸做催化剂进行对比实验收率为70.75%,超过硫酸催化剂水平。 相似文献
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Claudio Guilherme Portela de Carvalho Matheus Felipe da Silva José Marcos Gontijo Mandarino Anna Karolina Grunvald Nilza Patrícia Ramos José Lopes Ribeiro Vicente de Paulo Campos Godinho 《Journal of the American Oil Chemists' Society》2018,95(1):61-67
This study aimed to evaluate the fatty acid profiles of sunflower oil extracted from hybrid grains produced and stored in different environments. The trials were conducted in Teresina (Piauí), Vilhena (Rondônia), and Jaguariúna (São Paulo) in randomized complete block design with 4 replicates. After harvesting, grains from 1 high oleic and 3 traditional hybrids were packed in kraft paper bags and stored in a covered shed and in a cold chamber up to 12 months. The fatty acid profiles were determined by gas chromatography after 0, 4, 8, and 12 months of storage. Analyses of variance were conducted in a split‐plot design, with hybrids being considered as whole plots and storage times as subplots. Tukey's test was performed to compare hybrids and regression analyses for storage times. The initial fatty acid profile of the grains of the same hybrid varied depending on the production location. The grain storage of high oleic and traditional sunflower hybrids during 12 months in covered shed and in cold chamber resulted in little changes in oil fatty acid profiles, regardless of the initial contents. These changes occurred only for linoleic and palmitic acids. 相似文献
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Claudio Guilherme Portela de Carvalho Luana Fernanda Mazzola José Marcos Gontijo Mandarino Flávio Carlos Dalchiavon José Lopes Ribeiro Aluisio Brigido Borba Filho Alberto Donizete Alves 《Journal of the American Oil Chemists' Society》2019,96(9):1019-1025
This study aimed to verify whether the fatty acid profiles of mid-oleic genotypes grown in the tropical region of Brazil fit the Codex Alimentarius and to examine the possibility of using traditional inbred lines to produce high-oleic hybrids. For this purpose, we assessed the fatty acid profile of six mid-oleic hybrids grown in environments with different minimum temperatures during oil formation in the achenes. The tests were conducted between 2015 and 2017 in an experimentally randomized complete block design with four replications. The oleic, linoleic, palmitic, and stearic acid contents were determined using gas chromatography. The mid-oleic hybrids presented varying levels of fatty acids, with oleic acid ranging between 43.6% and 84.6%, linoleic acid between 8.5% and 45.6%, palmitic acid between 3.9% and 5.7%, and stearic acid between 2.2% and 6.2%. Some of the fatty acid values were outside the ranges established by the CODEX STAN 210-1999 and were characteristic of high-oleic type sunflowers. This finding shows that we can take advantage of the potential of combining traditional inbred lines to produce high-oleic hybrids for faster and more economical breeding programs in these environments. 相似文献
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Claudio Guilherme Portela de Carvalho Luana Fernanda Mazzola Andressa Caldeira Flávio Carlos Dalchiavon José Marcos Gontijo Mandarino 《Journal of the American Oil Chemists' Society》2019,96(7):789-794
The objective of this work was to evaluate the quality of the oil extracted from sunflower achenes grown in Campo Novo de Parecis, the main producing region of Brazil, to optimize its use by the processing and food industries. In addition, the fatty acid profiles of the oil were checked for their adherence to the CODEX STAN 210–1999. Traditional and high-oleic genotypes were grown between 2014 and 2017 during trials with a randomized complete block experimental design with four replications. The contents of oleic, linoleic, palmitic, and stearic acids were determined using gas chromatography. The fatty acid profiles of traditional genotypes were observed to be outside the ranges established by the CODEX, with an oleic acid content above 39.4% and linoleic, palmitic, and stearic acid values lower than 48.3%, 2.7%, and 5.0%, respectively, as well as high-oleic sunflower oil with a stearic acid content of less than 2.6%. The availability of this information can, on the one hand, positively impact industries and encourage the use of better quality raw materials that are more technologically and nutritionally adequate. On the other hand, the commercialization of sunflower oil with a fatty acid profile outside the ranges established by CODEX can be difficult, because the contents are out of specification due to the climatic conditions in the cropping region. 相似文献
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丘宝增胡静怡汤吉海等 《化工时刊》2014,(2):1-4
采用廉价的浓硫酸为催化剂,氧气为自由基捕集剂,以十二酸为原料,经氯化合成α-氯代十二酸。系统考察了反应温度、催化剂用量、氯气流量、氧氯比、反应时间等因素的影响,得到最佳工艺条件:十二酸20 g,在反应温度135℃、催化剂10%、氯气流量50 mL·min-1、vO2/vCl2=1∶2、反应时间3 h,可实现十二酸基本完全转化,目标产物α-氯代十二酸选择性达到94.5%。 相似文献