聚十二碳二酸乙二醇酯的合成反应动力学

在不同的反应温度和催化剂体系下 ,研究了十二碳二酸与乙二醇的外加强酸催化剂的聚酯化反应动力学 ,在反应控制阶段 ,动力学过程符合 Flory方程。通过红外光谱和核磁谱图 。

环己酮氧化法制备十二碳二酸工艺研究

以环己酮和双氧水为原料 ,甲醇为溶剂 ,在酸性条件下反应 ,生成甲氧基环己基过氧化物 ,使之在亚铁盐存在下和甲醇反应 ,生成十二碳二酸二甲酯 ,用无机碱皂化 ,无机酸酸析 ,得十二碳二酸粗品 ,再重结晶得成品 ,反应总收率 66% ;产品纯度大于 99%。

环已酮氧化法制备十二碳二酸工艺

以环己酮和双氧水为原料,以甲醇为溶剂,在酸性条件下反应,生成甲氧基环己基过氧化物,使之在亚铁盐存在下和甲醇反应,生成十二碳二酸二甲酯,然后用氢氧化钠皂化、无机酸酸析,得十二碳二酸粗品,再重结晶得成品。反应总收率66％,产品纯度大于99％。

十三碳二酸二异丁酯的合成

介绍了十三碳二酸二异丁酯的合成工艺、原料状况及产品的发展前景。

尼龙612合成技术开发项目通过鉴定

由中石化巴陵石化有限责任公司技术中心承担的尼龙612合成技术开发项目最近通过了中石化集团公司的技术鉴定。该技术采用环己酮氧化法合成十二碳二酸，再由十二碳二酸与己二胺熔融缩聚合成尼龙612树脂。产品已成功应用于高档牙刷丝、工业刷丝、工程塑料等方面。

水基防锈剂的制备及性能分析

随着人们的环保意识不断提升,为获得可持续性发展,也对环境友好提出了更高的要求,促使防锈剂开始向环境友好、多功能等方向发展。防锈剂保护技术的主要特征为用量少、见效快、成本低,其被广泛应用在机械行业、化工行业等。综上所述,本文将基于绿色环保理念,对水基防锈剂十二碳二酸二酰胺二乙醇胺硼酸酯的制备及其性能进行研究。

专利介绍

一种聚酯类弹性体及其制备方法专利 本发明以木糖醇为主单体,衣康酸、琥珀酸、十二碳二酸、十六碳二酸、十八碳二酸、十八碳烯二酸为共聚单体,采用熔融缩聚的方法得到木糖醇基聚酯弹性体。弹性体具有较好的生物相容性、生物降解性和低毒性;而且,木糖醇属于多羟基单体,与其它单体共聚时,可以通过改变共聚单体的种类和组成来调节聚合物的交联密度,

Effects of Culture Conditions on Growth and Docosahexaenoic Acid Production from Schizochytrium limacinum

The effects of temperature, initial pH, salinity of culture medium, and carbon and nitrogen sources on growth and doco- sahexaenoic acid (C22 : 6 n-3, DHA) production from Schizochytrium limacinum OUC88 were investigated in the present study. The results revealed that the optimal temperature, initial pH and salinity level of the medium for DHA production were 23℃, 7.0 and 18, respectively. Glucose was proved the best carbon source for the growth and DHA production from S. limacinum. Among the nitrogen sources tested, soybean cake hydrolysate, a cheap by-product, was found to be effective for the accumulation of DHA in S. lima- cinum cells. In addition, increasing the concentration of carbon sources in the medium caused a significant increase in cell biomass; however, accumulation of DHA in cells was mainly stimulated by the ratio of C/N in the medium. Under the optimal culture condi- tions, the maximum DHA yield achieved in flasks was 4.08 g L-1 after 5 d of cultivation.

Effect of pollution on DNA damage and essential fatty acid profile in Cirrhinus mrigala from River Chenab

The objective of this study was to evaluate the effect of anthropogenic pollution on DNA damage and the fatty acid profile of the bottom dweller fish （Cirrhinus mr^gala）, collected from the River Chenab, in order to assess the effect of the toxicants on the quality of the fish meat. The levels ofCd, Hg, Cu, Mn, Zn, Pb, Cr and Sn and of phenols from this river were significantly higher than the permissible limits set by the USEPA. Comet assays showed DNA damage in Cirrhinus mr^gala collected from three different sampling sites in the polluted area of the river. Significant differences were observed for DNA damage through comet assay in fish collected from polluted compared to control sites. No significant differences were observed for DNA damage between farmed and fish collected from upstream. The micronucleus assay showed similar trends. Fish from the highly polluted sites showed less number of fatty acids and more saturated fatty acids in their meat compared to fish from less polluted areas. Several fatty acids were missing in fish with higher levels of DNA in comet tail and micronucleus induction. Long-chain polyunsaturated fatty acids, eicosapentaenoic acid （20：5n-3） was found missing in the fish from polluted environment while it was found in considerable amount in farmed fish 7.8±0.4%. Docosahexaenoic acid （22：6n-3） also showed significant differences as 0.1±0.0 and 7.0±0.1% respectively, in wild polluted and fanned fishes.

Analysis of fatty acid composition of sea cucumber Apostichopus japonicus using multivariate statistics

Fatty acids(FAs) provide energy and also can be used to trace trophic relationships among organisms.Sea cucumber Apostichopus japonicus goes into a state of aestivation during warm summer months.We examined fatty acid profiles in aestivated and non-aestivated A.japonicus using multivariate analyses(PERMANOVA,MDS,ANOSIM,and SIMPER).The results indicate that the fatty acid profiles of aestivated and non-aestivated sea cucumbers differed significantly.The FAs that were produced by bacteria and brown kelp contributed the most to the differences in the fatty acid composition of aestivated and nonaestivated sea cucumbers.Aestivated sea cucumbers may synthesize FAs from heterotrophic bacteria during early aestivation,and long chain FAs such as eicosapentaenoic(EPA) and docosahexaenoic acid(DHA) that produced from intestinal degradation,are digested during deep aestivation.Specific changes in the fatty acid composition of A.japonicus during aestivation needs more detailed study in the future.

Docosahexaenoic acid suppresses arachidonic acid-induced proliferation of LS-174T human colon carcinoma cells

AIM： To investigate the impact of arachidonic acid （AA） and docosahexaenoic acid （DHA） and their combination on colon cancer cell growth. METHODS： The LS-174T colon cancer cell line was used to study the role of the prostaglandin precursor AA and the omega-3 polyunsaturated fatty acid DHA on cell growth. Cell viability was assessed in XTT assays. For analysis of cell cycle and cell death, flow cytometry and DAPI staining were applied. Expression of cyclooxygenase-2 （COX-2）, p21 and bcl-2 in ceils incubated with AA or DHA was examined by real-time RT-PCR. Prostaglandin E2 （PGE2） generation in the presence of AA and DHA was measured using a PGE2- ELISA. RESULTS： AA increased cell growth, whereas DHA reduced viability of LS 174T cells in a time- and dosedependent manner. Furthermore, DHA down- regulated mRNA of bcl-2 and up-regulated p21. Interestingly, DHA was able to suppress AA-induced cell proliferation and significantly lowered AA-derived PGE2 formation. DHA also down-regulated COX-2 expression. In addition to the effect on PGE2 formation, DHA directly reduced PGE2-induced cell proliferation in a dosedependent manner. CONCLUSION： These results suggest that DHA can inhibit the pro-proliferative effect of abundant AA or PGE2.

Lipid Oxidation and Fatty Acid Composition in Salt-Dried Yellow Croaker(Pseudosciaena polyactis) During Processing

Lipid oxidation in salt-dried yellow croaker(Pseudosciaena polyactis) was evaluated during processing with commonly used analytical indices, such as the peroxide value(POV), the thiobarbituric acid reactive substances(TBARS) value, and oxidative-relative lipoxygenase(LOX) activity. Additionally, fatty acids were analyzed using gas chromatography-mass spectrometry. Both POV and TBARS increased significantly(P < 0.05) at the rinsing stage. POV reached its peak value of 3.63 meq O_2 per kg sample at the drying stage, whereas TBARS constantly increased from 0.05 to 0.20 mg MDA per kg sample. Processing of salt-dried yellow croaker had an extremely significant(P < 0.01) effect on LOX activity. Twenty-six fatty acids were identified. Combined eicosapentaenoic acid(EPA; C20:5n3) and docosahexaenoic acid(DHA; C22:6n3) content varied between(19.20 ±0.37) mg g^(-1) and(23.45 ± 1.05) mg g^(-1). The polyunsaturated fatty acid/saturated fatty acid(PUFA/SFA) ratio in yellow croaker was 0.73–1.10, and the n-6/n-3 PUFA ratio was approximately 0.13–0.20. The contents of most fatty acids varied significantly(P <0.05) during the different processing stages, and these differences were caused by lipid oxidation. C18:0, C16:1n7, C19:0, and C22:6n3 showed clear changes in principle component one of a principle components analysis. These fatty acids are potential markers for evaluating lipid oxidation in fish muscle because there was a significant correlation between these markers and TBARS and LOX activity(P < 0.05) with Pearson's coefficients > 0.931.

Docosahexaenoic Acid and Eicosapentaenoic Acid Modulate Calcium Signaling in Murine CD36-Positive Taste Buds Cells, via Phospholipase Pathways

DHA （docosahexaenoic acid） and EPA （eicosapentaenoic acid） induced intracellular calcium increase in taste receptor cells purified from mouse circumvallate papillae. We have demonstrated that DHA and EPA induced calcium increase respectively via cPLA2 （cytosolic phospholipase A2） type lVc and calcium independent iPLA2 （phospholipase A2） type VI. Intracellular calcium increases via PLC （phospholipase C） pathway and leads to a calcium effiux and further SOC （stored operated calcium） channels activation. An abundant increase in intracellular calcium will induce exocytosis of neurotransmitters into the extracellular medium. Our results suggest that DHA and EPA induced calcium signaling, and should be implicated in the transmission of lipid gustatory information to afferent nerve fibers, as shown previously with linoleic acid.

The Effect of Feeding Laying Hen Conventional and Omega-3 Enriched Diet on Fatty Acid Profiles in Egg Yolk Lipids

The aim of this research was to enrich table eggs with n-3 polyunsaturated fatty acids （n-3 PUFA）, especially with essential eicosapentaenoic acid （EPA） and docosahexaenoic acid （DHA）. After five weeks of feeding of laying hens with standard and experimental diets, there was analysis carried out to determine the fatty acid profile in egg yolks of both groups. Omega-3 eggs contain statistically significantly （P 〈 0.05） less sum of saturated fatty acids （∑SFA） and more∑n-3 PUFA, as well as narrower ratio of∑n-6/∑n-3 PUFA than conventional eggs. If referring to individual fatty acids of omega-3 eggs, there were increased portions （P 〈 0.05） of α-linolenic acid （α-LNA）, docosapentaenoic acid （DPA）, EPA and DHA determined in this research, which was in line with the research objective. Within the presented research, concentration of n-3 PUFA in egg yolk lipids of experimental group was two times higher than that in the control group. The ratio of ∑n-6 PUFA/∑n-3 PUFA was reduced from 12.04 to 6.17. Within their enzymatic system, laying hens can act as a bioreactor to naturally enrich their eggs with n-3 PUFA, especially with EPA and DHA. The results of this research proved that the fatty acid profile can be modified by designing of laying hens＇ diets with specific forages. Eggs were enriched with favorable fatty acids in the following order： α-LNA 〉 DHA 〉 DPA 〉 EPA.

Effect of Dietary Lipid Levels on Fatty Acids Composition of Cultured Sparusaurata

The aim of this study was to determine the progressive evolution of fish muscle fatty acids composition feeding by different lipid levels of farmed Mediterranean gilthead sea bream （Sparusaurata）. During twenty one weeks, Sparusaurata were hand-feed two diets with protein and lipid ratios 47/20 （Diet A） and 45/22 （Diet B） respectively. At the end of the feeding period, lipid contents of muscle, as well as fatty acids profiles of different portions of the muscles were studied. Results indicated the effects of fatty acids profiles of diets throughout the liver and white muscle fillet （dorsal, middle and ventral）. These were more noticeable when Sparusaurata was fed on the diet Athat decreased the content of monounsaturated fatty acids （MUFA）, and polyunsaturated fatty acids （PUFA） in all the muscles during the period of feeding while the saturated fatty acids （SFA） content tended to increase and it was lower than ones in the muscles of Sparusaurata fed on diet B. The highest amount of PUFA and docosahexaenoic acid, （22：6n-3 DHA） were found among the different portions of ventral muscles. In addition, the progressive evolution of different parts of muscle＇s fatty acid profiles showed significant differences in contents of SFA, PUFA and especially the n-3 PUFA. However, the content of MUFA seems to be alike in different muscles and tended to decrease in dorsal and ventral muscle from Do to Df and inversely when the fish were fed on diet A.

Effectiveness of omega-3 polyunsaturated fatty acids against microbial pathogens

Microorganisms provide both beneficial and harmful effects to human beings. Beneficial effects come from the symbiotic relationship that exists between humans and microbiota, but then several human illnesses have turned some friendly microbes into opportunistic pathogens, causing several microbial-related diseases. Various efforts have been made to create and utilize antimicrobial agents in the treatment and prevention of these infections, but such efforts have been hampered by the emergence of antimicrobial resistance. Despite extensive studies on drug dis- covery to alleviate this problem, issues with the toxicity and tolerance of certain compounds and continuous microbial evolution have forced researchers to focus on screening various phytochemical dietary compounds for antimicrobial activity. Linolenic acid and its derivatives （eicosapentaenoic acid and docosahexaenoic acid） are omega-3 fatty acids that have been studied due to their role in human health, being important for the brain, the eye, the cardiovascular system, and general human growth. However, their utilization as antimicrobial agents has not been widely appreciated, perhaps due to a lack of understanding of antimicrobial mechanisms, toxicity, and route of administration. Therefore, this review focuses on the efficacy, mechanism, and toxicity of omega-3 fatty acids as alternative therapeutic agents for treating and preventing diseases associated with pathogenic microorganisms.

Acid sensitive doxorubicin-PAMAM with tumor targeting profile

Poly （amidoamine） dendrimers are emerging as versatile and derivatizable nano-scale drug delivery vehicles. In our study, cis-4,7,10,13,16,19-docosahexenoic acid and doxorubicin were conjugated to generation 2.5 PAMAM. The molecular architecture of the carrier was designed for optimized blood circulation and optimized drug release through the use of pH-sensitive hydrazone linkages. In vitro, DHA-PAMAM-DOX conjugates were able to release twice as much doxorubicin at pH 4.5 （lysosomal pH） as at pH 7.4, ensuring more pronounced antitumor activity. Upon intravenous administration to ICR mice, the DHA-PAMAM-DOX delivery systems resulted in more plasma exposure of doxorubicin than free doxorubicin solution. In efficacy studies performed with B6D2F1 mice bearing B16 melanoma tumors, DHA-PAMAM-DOX was significantly more efficient in inhibiting tumor growth than free doxorubicin at the dose equivalent to 5 mg/kg doxorubicin. Our research provides evidence that DHA-PAMAM-DOX conjugates have the potential to enhance the effect of cancer therapy in the course of delivering anticancer drugs to their target sites.

Fatty acid profiles of muscle from large yellow croaker (Pseudosciaena crocea R.) of different age

We investigated the fatty acid profiles of muscle from large yellow croaker （Pseudosciaena crocea R.） of different age. One- and two-year-old fish were cultured in floating net cages and sampled randomly for analysis. Moisture, protein, lipid and ash contents were determined by methods of Association of Analytical Chemist （AOAC） International. Fatty acid profile was deter- mined by gas chromatography. Crude protein, fat, moisture and ash contents showed no significant differences between the two age groups. The contents of total polyunsaturated fatty acids and docosahexaenoic acid （DHA） were significantly higher and eicosapentaenoic acid （EPA） content was significantly lower in the two-year-old large yellow croaker than in the one-year-old （/＇〈0.05）. No significant differences were observed in the contents of total saturated fatty acids and monounsaturated fatty acids, or the ratio ofn-3/n-6 fatty acids among the large yellow croakers of the two age groups. We conclude that large yellow croakers are good food sources of EPA and DHA.