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用固定化脂肪酶Lipozyme 435作催化剂,由D-异抗坏血酸和月桂酸合成D-异抗坏血酸月桂酸酯。考察了反应温度、反应溶剂、反应物配比、酶用量、反应时间、月桂酸浓度、分子筛用量、摇床转速对产物收率的影响。结果表明,以20mL叔戊醇为反应溶剂、0.10g脂肪酶为催化剂、2.0g 4A分子筛为脱水剂,在55℃、170r/min转速的恒温摇床中,0.88g D-异抗坏血酸和2.50g月桂酸反应36h,产物收率68%。产物结构经IR、1H NMR、13C NMR和MS表征。 相似文献
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酯交换法合成D-异抗坏血酸棕榈酸酯及其抗氧化性能 总被引:10,自引:0,他引:10
24℃下,2.9gD 异抗坏血酸和3.8g棕榈酸甲酯分别缓慢加入到14mL的浓硫酸中,搅拌反应24h。反应混合物加入到冰水中,用乙醚萃取,洗涤,除去乙醚,粗产品用甲苯重结晶,得到4.6gD 异抗坏血酸棕榈酸酯,产率79%。用FTIR对产品进行了表征。按国标(GB/T5009.37—1996)方法将产品用于新鲜茶籽油进行抗氧化性能实验,结果表明,D 异抗坏血酸棕榈酸酯是一种比L 抗坏血酸棕榈酸酯更好的油溶性抗氧化剂。 相似文献
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苯酚与苯甲酰氯在无吡啶条件下进行反应制备苯甲酸苯酯。苯甲酰氯直接与苯酚混合而不同用滴加。该法操作简单,收率高。 相似文献
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研究了以苯甲酰氯和哌啶醇为原料直接缩合合成苯甲酸哌啶醇酯受阻胺光稳定剂(HALS)时反应温度、反应时间、原料配比等条件对合成反应的影响,确定了最佳工艺条件。最适宜的工艺条件是:反应温度95℃、反应时间6h、原料摩尔比n(哌啶醇):n(苯甲酰氯)为1:1.4,溶剂用量为70mL(相对于0.1mol哌啶醇),苯甲酸哌啶醇酯的收率为91.05%,产品纯度98.5%。 相似文献
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以槲皮素为原料、浓硫酸作催化剂,85℃与苯甲酰氯反应,TLC板监测反应完毕,过滤、氯仿/甲醇重结晶合成标题化合物。UV表征显示,槲皮素的两个特征吸收峰均发生蓝移,这是形成新化合物共轭体系引起的。IR中ν—OH峰明显减弱,说明槲皮素的5个羟基中有的羟基发生了反应;νCO位于1 745.32 cm-1,酯羰基峰明显增强;νC—O位于1 259.66cm-1,峰变宽增强。1HNMR中3-OH、3'-OH、4'-OH上面的氢消失,说明与苯甲酰氯发生了酯化反应;同时,在δ6.7~8.4处有苯甲酰基的多重峰。MS中m/z 615.2为槲皮素三苯甲酸酯的分子离子峰。因此,槲皮素与苯甲酰氯反应可以得到标题化合物。 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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反-β-正烷氧羰基丙烯酸与SOCl2反应得到反-β-正烷氧羰基丙烯酰氯,后者再与D-异抗坏血酸反应,得到标题化合物。其结构经IR、1HNMR、13CNMR和MS确证。用分光光度法测试了反-β-正己氧羰基丙烯酸-6-D-异抗坏血酸酯清除DPPH自由基的活性,用孔穴扩散法测试了标题化合物的抗菌活性。结果表明,在物质的量浓度相等时,D-异抗坏血酸与反-β-正己氧羰基丙烯酸-6-D-异抗坏血酸酯对DPPH自由基的清除率基本接近;在给药量为2 mg/mL时,标题化合物对金黄葡萄球菌、大肠杆菌、枯草芽孢杆菌的抑菌圈直径在5.00~7.25 mm之间,对细黄链霉菌的抑菌圈直径在15.00~17.50 mm之间。 相似文献
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《化学世界》2017,(10)
以芦丁为原料,甲醇钠调pH=9.5,54℃与苯甲酰氯反应,薄层色谱(TLC)板监测反应完毕,过滤、乙醇/丙酮重结晶。紫外光谱(UV)显示芦丁的两个特征吸收峰均发生蓝移,这是形成新化合物共轭体系变化引起的。IR中νOH峰明显减弱,说明芦丁中多个羟基发生了反应,νc=o位于1 755.36cm~(-1),酯羰基峰明显增强;νc—o位于1 219.18cm~(-1),变宽增强。1 H NMR中7-OH、3′-OH、4′-OH上面的氢消失,说明与苯甲酰氯发生了酯化反应,同时,在7.6~8.8处有苯甲酰基的多重峰。MS中m/z:921.2为芦丁三苯甲酸酯的分子离子峰。 相似文献
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S. S. Duffey M. S. Blum H. M. Fales S. L. Evans R. W. Roncadori D. L. Tiemann Y. Nakagawa 《Journal of chemical ecology》1977,3(1):101-113
Analyses of the defensive secretions of 17 species of polydesmoid millipedes show that other chemicals besides HCN and benzaldehyde are liberated during cyanogenesis. Several members of the families Polydesmidae, Paradoxosomatidae, and Euryuridae are shown to secrete both phenol and guaiacol, with one paradoxosomatid also producing ethyl benzoate and benzoic acid. Also, members of the family Xystodesmidae commonly produce the three following compounds: benozoic acid, mandelonitrile benzoate, and benzoyl cyanide. Benzoyl cyanide has not been found previously as a natural product. The defensive role of these additional natural products as antipredator and antibiotic agents is discussed. For certain predators benzoyl cyanide in particular seems to possess anaesthetic properties. Our studies provide an initial chemotaxonomic basis for distinguishing between various polydesmoid taxa. 相似文献
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Benzoyl chloride is commonly used as a food preservative to control microbial contamination by reducing the growth rate and maximum growth population and extending the lag period of the target microorganisms. Benzoyl chloride was successfully incorporated into a matrix of an ethylene acrylic acid polymer. The reaction of benzoyl chloride with ethylene acrylic acid was confirmed by Fourier transform infrared spectroscopy. The antimicrobial activity of modified ionomer films was studied through the monitoring of the growth of Penicillium sp. and Aspergillus sp. on the modified films. An untreated film did not show any inhibition of microbial growth. The inhibition activity was least in an ionomer film treated with acid and benzoyl chloride, and this was followed by a film treated with alkali and benzoyl chloride. The maximum inhibition was observed in a film treated just with benzoyl chloride. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3063–3068 2006 相似文献
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Cerium oxide nanoparticles (CeO2-NPs) have been biosynthesized using the aqueous extract of aerial parts of Prosopis farcta. This plant contains phenolic compounds that function as reducing and capping agents. Biosynthesized particles have been characterized through the use of UV–vis, PXRD, TEM, FESEM, EDX, Raman and FTIR analysis. The UV–vis spectrum clearly showed absorption peak at 317?nm, which indicated the formation of spherical CeO2-NPs. It displayed in the FESEM and TEM images that the biosynthesized particles are uniformly and spherically shaped with a size of about 30?nm, while the EDX has clearly shown that only the elements Ce and O are present in the biosynthesized sample. Moreover, the Raman spectrum of synthesized nanoparticles has displayed a Ce-O stretching band at a measurement of 459?cm?1. The cytotoxic activity of biosynthesized nanoparticles against the HT-29 cancer cell line was studied using the MTT assay. All the concentrations of CeO2-NPs (0–800?µg/ml) showed non-toxic effects and thus, it can be suggested that these nanoparticles have the potential of being utilized in various fields of medicine, such as drug delivery. 相似文献