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1.

Abstract  

The hydrophobation of rosmarinic acid with saturated aliphatic primary alcohols of various chain lengths (methanol to eicosanol) was achieved via an acid-catalyzed esterification in the presence of a highly acidic sulfonic resin. The resulting alkyl rosmarinates were isolated, characterized and their global free radical scavenging activity was determined by the 2,2-diphenyl-1-picrylhydrazyl method in the stationary state. Only the dodecyl ester showed a stronger activity than rosmarinic acid.  相似文献   

2.
研究了不同碳链长度的脂肪酸与N-甲基二乙醇胺的酯化反应。以月桂酸为原料,通过正交实验考察了反应温度、物料摩尔比、回流液温度、催化剂用量等因素对该酯化反应的影响,确定了较优的工艺条件为:反应温度200℃,n(月桂酸)∶n(N-甲基二乙醇胺)=1.8∶1.0,回流液温度70℃,催化剂用量(相对于反应原料的质量)0.3%。在该工艺条件下,酯化产物中甲基二乙醇胺双月桂酸酯(双酯胺)的质量分数可达98%以上。并对正辛酸、正癸酸、棕榈酸和硬脂酸与N-甲基二乙醇胺的酯化反应条件进行了优化,得到的产物中双酯胺的质量分数达98%以上。采用IR和1HNMR对双酯胺的结构进行了表征。  相似文献   

3.
Fatty acid amino acid conjugates (FACs) have been found in noctuid as well as sphingid caterpillar oral secretions; in particular, volicitin [N-(17-hydroxylinolenoyl)-L-glutamine] and its biochemical precursor, N-linolenoyl-L-glutamine, are known elicitors of induced volatile emissions in corn plants. These induced volatiles, in turn, attract natural enemies of the caterpillars. In a previous study, we showed that N-linolenoyl-L-glutamine in larval Spodoptera litura plays an important role in nitrogen assimilation which might be an explanation for caterpillars synthesizing FACs despite an increased risk of attracting natural enemies. However, the presence of FACs in lepidopteran species outside these families of agricultural interest is not well known. We conducted FAC screening of 29 lepidopteran species, and found them in 19 of these species. Thus, FACs are commonly synthesized through a broad range of lepidopteran caterpillars. Since all FAC-containing species had N-linolenoyl-L-glutamine and/or N-linoleoyl-L-glutamine in common, and the evolutionarily earliest species among them had only these two FACs, these glutamine conjugates might be the evolutionarily older FACs. Furthermore, some species had glutamic acid conjugates, and some had hydroxylated FACs. Comparing the diversity of FACs with lepidopteran phylogeny indicates that glutamic acid conjugates can be synthesized by relatively primitive species, while hydroxylation of fatty acids is limited mostly to larger and more developed macrolepidopteran species.  相似文献   

4.
The development of intravitreal glucocorticoid delivery systems is a current global challenge for the treatment of inflammatory diseases of the posterior segment of the eye. The main advantages of these systems are that they can overcome anatomical and physiological ophthalmic barriers and increase local bioavailability while prolonging and controlling drug release over several months to improve the safety and effectiveness of glucocorticoid therapy. One approach to the development of optimal delivery systems for intravitreal injections is the conjugation of low-molecular-weight drugs with natural polymers to prevent their rapid elimination and provide targeted and controlled release. This study focuses on the development of a procedure for a two-step synthesis of dexamethasone (DEX) conjugates based on the natural polysaccharide chitosan (CS). We first used carbodiimide chemistry to conjugate DEX to CS via a succinyl linker, and we then modified the obtained systems with succinic anhydride to impart a negative ζ-potential to the polymer particle surface. The resulting polysaccharide carriers had a degree of substitution with DEX moieties of 2–4%, a DEX content of 50–85 μg/mg, and a degree of succinylation of 64–68%. The size of the obtained particles was 400–1100 nm, and the ζ-potential was −30 to −33 mV. In vitro release studies at pH 7.4 showed slow hydrolysis of the amide and ester bonds in the synthesized systems, with a total release of 8–10% for both DEX and succinyl dexamethasone (SucDEX) after 1 month. The developed conjugates showed a significant anti-inflammatory effect in TNFα-induced and LPS-induced inflammation models, suppressing CD54 expression in THP-1 cells by 2- and 4-fold, respectively. Thus, these novel succinyl chitosan-dexamethasone (SucCS-DEX) conjugates are promising ophthalmic carriers for intravitreal delivery.  相似文献   

5.
李士锋  鞠军  李红  聂鑫  廖春泉  于世钧 《辽宁化工》2007,36(11):745-747,760
以3,5-二硝基苯甲酰氯、4-氨基丁酸和11-氨基十一烷酸为原料,合成了两种超支化聚酰胺AB2型单体——4-(3,5-二氨基苯甲酰氨基)丁酸和11-(3,5-二氨基苯甲酰氨基)十一烷酸。改进了含有两个硝基的羧酸类化合物还原成氨基酸类化合物的方法,采用钯炭催化加氢还原,简化了实验操作及后处理,产品收率达91.2%和93.8%。通过FT-IR、1H NMR和13C NMR对相关化合物进行了结构表征。  相似文献   

6.
以脂肪胺,氯乙酰氯和谷氨酸钠为原料,合成了含甲基酰胺基团的谷氨酸型表面活性剂。经IR1、H NMR及13C NMR对产物进行结构表征,证实合成的化合物为目标产物。25℃下,用滴体积法测定该系列化合物的表面张力γCMC和CMC。结果表明,由于甲基酰胺的引入,使该表面活性剂有较低的CMC,随着碳链长度的增加CMC逐渐降低,γCMC逐渐增大,当疏水链为C16烷基时,CMC达到最低值1.26 mmol/L,与之相对应的γCMC为最大值43.8 mN/m,且随着碳链的增长,Γmax逐渐变小,Amix逐渐变大。  相似文献   

7.
以菜籽油脂肪酸甲脂为原料,分别与乙醇胺和二乙醇胺在碱性条件下反应,合成脂肪酸单乙醇酰胺、1∶1型脂肪酸二乙醇酰胺和1∶2型脂肪酸二乙醇酰胺,并对这三种烷醇酰胺进行系统的性能测试。结果表明由菜籽油脂肪酸甲脂合成的脂肪酸单乙醇酰胺的胺值低、乳化性好和cmc低,但起泡性、润湿性和钙皂分散力较差;1∶1型脂肪酸二乙醇酰胺乳化性和钙皂分散力较好,但水溶性和起泡性较差;1∶2型脂肪酸二乙醇酰胺乳化效果差,胺值高,但起泡性和润湿性较好。三种烷醇酰胺性能不尽相同,为表面活性剂开发和生物柴油的综合利用探索了一条新的途经。  相似文献   

8.
以N,N-二甲基乙酰胺/LiCl为溶剂,以对甲苯磺酰氯为共反应剂原位活化金刚烷甲酸,在均相反应体系中合成了新的纤维素高级脂肪酸酯——金刚烷甲酸纤维素酯。采用红外光谱、核磁共振谱进行了表征。热重分析表明,在纤维素链中引入金刚烷基可提高其热稳定性,取代度越高,热稳定性越好。金刚烷甲酸纤维素酯在有机溶剂中的溶解性随取代度增大而提高。  相似文献   

9.
10.
Copolymers including hydroquinone and vinylpyridine units have been prepared by the copolymerization reaction of quinones with vinylpyridines. By-products of these reactions are the homopolymer and the hydroquinone form of the respective quinone. It has been established that in the formation of the copolymers, the weak intermolecular complexes of quinones (Qs) with vinylpyridines (VPs) have an essential contribution. The kinetics of Q copolymerization with VP in the presence of triethylamine has been investigated. The values of the reaction order based on the components, the rate constants and activation energies of the copolymerization processes have been determined. The copolymers prepared are soluble in polar organic solvents, have high reactivity for electron exchange, and possess antioxidant, antihypoxemic and antistatic properties. © 1997 SCI  相似文献   

11.
耿二欢  孙永强  张勇  孙晋源 《当代化工》2014,(12):2529-2531,2534
聚甘油脂肪酸酯与AEO9复配,对复配体系的性能进行测定,结果表明:m(AEO9)∶m(PGFE)为8∶1时复配体系的cmc和γcmc最低,泡沫体积最大,泡沫稳定性最好;m(AEO9)∶m(PGFE)为1∶2时对体系石蜡的乳化力最强,m(AEO9)∶m(PGFE)为2∶1对大豆油的乳化力最强;复配体系的润湿性能有所提高。  相似文献   

12.
聚乙二醇单甲醚脂肪酸酯的碱催化合成及性能   总被引:5,自引:0,他引:5  
在碱催化下通过聚乙二醇单甲醚(PGME)和脂肪酸甲酯的酯交换反应合成了PGME脂肪 酸酯。在酯和醇醚摩尔比为1:1.2.催化剂质量分数为05%、反应温度120℃、反应时间6.5h条 件下,对脂肪酸甲酯的摩尔收率可达90%。用IR、~(13)CNMR对产物结构进行了确证,同时对产物 的表面物性进行了测试。  相似文献   

13.
Seed oils consist mainly of triglycerides, that is, they comprise a unit of glycerol backbone esterified with three acyl groups (usually but not limited to C16–C18) which may be saturated or unsaturated with one or more olefinic functionalities per acyl group. Very rarely do seed oils contain additional functional groups, such as hydroxyls as in castor and lesquerella seeds. Milkweed seed oil follows the natural triglyceride patterns, but with a difference in being highly poly olefinic. This character allows for the introduction of different reactive groupings into the structure of the oil so as to be amenable to tailoring to a variety of uses. Synthesis of the milkweed polyhydroxy triglyceride (MWPHTG) from the polyoxirane triglyceride derivative of milkweed oil using in situ peroxy acid epoxidation of the oil was previously reported. Subsequent acidolysis of the epoxy derivative gave the MWPHTG. Here the polyhydroxy triglyceride was saponified for glycerol removal thus generating the polyhydroxy fatty acids of milkweed oil. Studies of the physical characteristics, flow and stability of the resulting hydroxylated fatty acids using FTIR, NMR, DSC, Rheometry and TGA indicate a stable material with unique properties that would be useful as additives in many applications such as pharmaceuticals.  相似文献   

14.
A new nonlinear polysilylether containing azomethine group was synthesized from 3,4-di-(2′-hydroxyethoxy)-4′-nitrobenzylidene with dichlorodiphenylsilane in the presence of anhydrous pyridine. The chemical structure of the polysilylether was characterized by C–H–N analysis and FT-IR, 1H-NMR, 29Si-NMR, and UV-Vis spectroscopy. The nonlinear optical property of the new polysilylether has been studied via the second harmonic generation (SHG) and the values of electro-optic coefficients d33 and d31 of the poled polysilylether film were 7.88 × 10−5 and 5.70 × 10−5 esu, respectively. The thermal behavior of the polysilylether was studied by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC).  相似文献   

15.
More than the sum of its parts : The seeds of Nigella sativa have been a traditional herbal remedy for ailments such as asthma, diarrhea, and cancer. Their essential oil is rich in polyunsaturated fatty acids and thymoquinone. By linking them covalently, a tremendous boost in anticancer activity can be achieved in resistant tumor cells.

  相似文献   


16.
Toxoplasma gondii (T. gondii) is a highly prevalent parasite that has no gold standard treatment due to the poor action or the numerous side effects. Focused sulfonamide-1,2,3-triazole hybrids 3a–c were wisely designed and synthesized via copper catalyzed 1,3-dipolar cycloaddition approach between prop-2-yn-1-alcohol 1 and sulfa drug azides 2a–c. The newly synthesized click products were fully characterized using different spectroscopic experiments and were loaded onto chitosan nanoparticles to form novel nanoformulations for further anti-Toxoplasma investigation. The current study proved the anti-Toxoplasma effectiveness of all examined compounds in experimentally infected mice. Relative to sulfadiazine, the synthesized sulfonamide-1,2,3-triazole (3c) nanoformulae demonstrated the most promising result for toxoplasmosis treatment as it resulted in 100% survival, 100% parasite reduction along with the remarkable histopathological improvement in all the studied organs.  相似文献   

17.
For application of n-3 fatty acids, distribution of the fatty acid compositions of different parts of (head, tail, fins and skin = HTFS, liver, viscera and muscle tissue) five commercially important fish species from the Persian Gulf (Scomberomorus commersoni, Thunnus tonggol, Euthynnus affinis, Scomberomorus guttatus and Dussumieria acuta) as good sources of n-3 PUFA were studied. The richest source of n-3 were HTFS in S. guttatus and S. commersoni, liver in S. guttatus, total body of D. acuta, liver of E. affinis and T. tonggol, followed by viscera of E. affinis. The content of these fatty acids were the same in viscera of tonggol, liver of S. commersoni, and HTFS of E. affinis. Moreover, muscle of E. affinis and HTFS of T. tonggol and also muscle of S. guttatus and T. tonggol had the same n-3 contents as the viscera of S. commersoni. So, it was concluded that HTFS and viscera (which are discarded as residues) are as useful as muscle and liver and can be a source of economically available n-3 PUFA. Muscle had the lowest proportion of n-3 in E. affinis, T. tonggol, and S. guttatus in comparison with other organs of these fish species. The highest n-3:n-6 ratio was observed in D. acuta. Finally, the cluster analysis showed that with respect to n-3 and other PUFA contents, HTFS of S. commersoni and D. acuta with S. guttatus on the one hand, and HTFS of T. tonggol and E. affinis on the other hand were similar to each other. In addition, viscera of S. commersoni and S. guttatus were similar followed by T. tonggol and different from E. affinis and D. acuta. In the case of muscle, T. tonggol and S. guttatus had good similarity followed by E. affinis and had no significant similarity with S. commersoni and D. acuta. With regard to liver, the highest similarity was observed between T. tonggol and E. affinis followed by D. acuta and S. guttatus, while S. commersoni did not show similarity with the others.  相似文献   

18.
以没食子酸甲酯为原料,通过醚化反应合成含十二烷基的没食子酸衍生物2。该衍生物进一步与水合肼肼解得到含十二烷基的没食子酸酰肼3。化合物3再与对苯二甲醛反应,合成了新型十二烷基没食子酸席夫碱二聚体4,分离简便,产率高。新化合物的结构经红外、核磁和质谱表征。差热分析和偏光显微镜观察表明,其具有很好的液晶性能。  相似文献   

19.
A series of fatty acid amides of 3,4‐methylenedioxymethamphetamine (MDMA) catechol metabolites were synthesized in order to evaluate their biological activities. Upon administration, all synthesized compounds resulted in negative modulation of food intake in rats. The most active compounds have affinity for the CB1 receptor and/or PPAR‐α; part of their biological activity may be caused by these double interactions.  相似文献   

20.
以马来海松酸为原料,先合成马来海松酸酰氯,然后和烯丙醇进行酯化反应,合成马来海松酸烯丙酯,得率为 70 %,质量分数 99.2 %。采用FT-IR、GC-MS、 13C NMR 和DSC对其结构和性能进行分析。研究结果表明,马来海松酸烯丙酯是一种含有酸酐基团的烯丙基类单体,加热到熔点以上可以发生聚合反应,均聚物玻璃化转变温度约为 98 ℃,可作为环氧树脂和不饱和树脂前聚体。  相似文献   

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