富里酸诱导对三角褐指藻EPA合成积累的影响

探究不同富里酸作用浓度对三角褐指藻二十碳五烯酸（EPA）合成积累的影响。结果表明,在20 mg/L富里酸诱导下,三角褐指藻EPA含量和产量均达到最大值,为19.81 g/100 g和738.91 mg/L,较无富里酸诱导EPA含量和产量分别提高2.01和2.54倍。外源富里酸作用提高了三角褐指藻胞内过氧化物酶（POD）、超氧化物歧化酶（SOD）、过氧化氢酶（CAT）酶活,使得色素和多酚抗氧化组分比例增加,活性氧（ROS）和丙二醛（MDA）水平降低,整体抗氧化能力获得显著提升,有效阻抑EPA的氧化分解;富里酸作用同时还上调了EPA合成通路脱饱和酶（Δ5-FADS、Δ6-FADS、Δ12-FADS、Δ15-FADS、Δ17-FADS）和延长酶（Δ6-ELOVL）等系列关键酶,使其上调表达量较无富里酸作用分别增加1.27、1.81、1.24、1.45、1.43和1.46倍,为EPA高效合成积累提供前驱物和能量。富里酸作用效果协同强化了三角褐指藻EPA合成积累效率。     

营养元素对三角褐指藻生长和脂类积累的影响

研究了不同营养元素(氮、磷、硅、铁)在不同培养浓度条件下,对三角褐指藻生长以及细胞脂类积累的影响作用。结果显示:藻细胞生长随氮含量的增加而增加,但超过一定浓度后作用不明显,最适合三角褐指藻生长的氮含量为 1.76 mmol/L。缺氮和低氮(0.22~0.44 mmol/L)培养能够明显提高藻细胞脂类含量。缺磷培养能有效促进藻株脂类积累,但是藻细胞生长受到明显抑制。缺硅导致藻细胞的生长减缓,但是对藻细胞的油脂积累影响不显著。在缺铁和高铁(0.048 mmol/L)条件下,藻的总脂含量均高于正常的培养条件。实验证明通过两步培养的方法,先在营养充足的培养基中进行藻细胞生长,然后将藻细胞转移到海水中培养,可以明显提高藻细胞的油脂含量。最终本实验确定海水为诱导三角褐指藻脂类积累的最佳诱导培养基。     

海水小球藻和三角褐指藻对U(Ⅵ)的吸附研究

以冷冻干燥法制备海水小球藻和三角褐指藻藻粉,考察pH、时间、温度、初始U(Ⅵ)浓度、盐浓度等对两种微藻在水溶液中吸附U(Ⅵ)的影响,并由Langmuir模型拟合结果分析得出海水小球藻和三角褐指藻对U(Ⅵ)的吸附量最高分别达1 314.0 mg/g和1 450.0 mg/g。采用BM、SEM、EDS、FTIR等方法对两种微藻吸附U(Ⅵ)前后形貌及结构进行表征,分析可能存在的吸附机理。此外,模拟深海高压环境考察藻粉对U(Ⅵ)的吸附,得出2种藻粉在一定超高压环境下U(Ⅵ)吸附性能良好,且三角褐指藻优于海水小球藻。     

仙婷(中国)有限公司代理的三角褐指藻提取物正式投放市场

仙婷(中国)有限公司(SETHICCHINA)(www．ethic-china．eom)于2(D4年10月19日在广州正式宣布向市场投放三角褐指藻提取物(Thalassane)，它是由克里斯汀．迪奥(Christian Dior)研究中心开发的微藻类提取物，其功效是使皮肤恢复到年轻时的状态。三角褐指藻提取物是通过一种新颖的作用机理发挥其功效的，那就是“泛素调节的蛋白质降解”，     

几种酞酸酯对海洋微藻的生长抑制效应

通过96h的急性毒性试验,研究了邻苯二甲酸二甲酯(DMP)、邻苯二甲酸二乙酯(DEP)、邻苯二甲酸二丁酯(DBP)、邻苯二甲酸二辛酯(DOP)对三角褐指藻(Phaeodactylum tricornutum),小球藻(Chlorella spp.),扁藻(Platymonas spp.)和叉鞭金藻(Dicrateria sp.)四种海洋微藻的致毒效应,探讨了四种海洋微藻对DMP、DEP、DBP、DOP的耐受性及之间的相互作用。结果显示DMP、DEP、DBP、DOP在10～200mg/L的有机物浓度梯度下对四种微藻的生长均有不同程度的抑制,特别是在高浓度组下的抑制特别明显。四种微藻的耐受程度有所差别,其中三角褐指藻最为敏感,叉鞭金藻耐受性最强。     

酶促合成含侧链官能取代基手性聚(丁二酸-辛二醇)酯

用酶促聚合的方法,制备了3种含不同侧链官能取代基(包含杂环、芳香、脂肪取代基)的手性聚酯。所有聚合物的结构都通过红外光谱(IR)、核磁共振氢谱(¹H NMR)确认,聚合物的相对分子质量由凝胶渗透色谱(GPC)测定,通过该方法合成的手性聚酯相对分子质量均在8.9×10³～12.1×10³。     

褐煤粒度对碱法制备胡敏酸和富里酸的影响

以不同粒度的白音华褐煤碱性煤浆为原料,5%(质量分数,下同)NaOH溶液和1 mol/L H2SO4溶液为pH值调节剂,制备胡敏酸和富里酸。通过容量法和紫外可见分光光度法分析胡敏酸和富里酸的含量、提取率、E4/E6值和DPPH(1,1-二苯基-2-三硝基苯肼)抗氧化活性,探讨褐煤粒度对胡敏酸和富里酸的影响规律。结果表明:当褐煤粒度减小到13.28μm时,胡敏酸和富里酸的总提取率为86.34%,胡敏酸与富里酸的分子量和芳香缩合度最为相似。该粒度条件下,富里酸的提取率可达62.28%,游离腐植酸质量分数为47.4%,DPPH自由基清除率为41.3%,富里酸的抗氧化活性显著。     

要闻链接

仙婷(中国)有限公司代理的三角褐指藻提取物正式投放市场仙婷(中国)有限公司(SETHICCHINA)(www seth ic china.com)于2004年10月19日在广州正式宣布向市场投放三角褐指藻提取物(Thalassane) ,它是由克里斯汀 迪奥(ChristianDior)研究中心开发的微藻类提取物 ,其功效是使皮肤恢复到年轻时的状态。三角褐指藻提取物是通过一种新颖的作用机理发挥其功效的 ,那就是“泛素调节的蛋白质降解” ,也正是这个机理使其发现者(以色列科学家阿龙·切哈诺沃、阿夫拉姆·赫什科和美国科学家欧文·罗斯)在2004年10月6日获得了诺贝尔化学奖。在20世纪…     

油酸和十二烷二酸的氨基酸酯的合成及其生物抗菌性

以L-丙氨酸乙酯盐酸盐、甘氨酸乙酯盐酸盐、L-蛋氨酸甲酯盐酸盐、L-亮氨酸乙酯盐酸盐和L-酪氨酸甲酯盐酸盐在1-乙基-(3-二甲基氨基丙基)碳酰二亚胺盐酸盐和1-羟基苯并三唑(HOBt)的作用下分别与油酸进行反应，生成了5种油酸的氨基酸衍生物；将L-丙氨酸乙酯盐酸盐和甘氨酸乙酯盐酸盐分别与十二烷二酸进行反应，生成了两种十二烷二酸的氨基酸衍生物，7种产物的收率均≥75%。利用FTIR、TGA、¹HNMR和LC-MS对产物进行了表征，测试了产物的水油分散性，考察了产物对金黄色葡萄球菌和大肠杆菌的抑菌性。结果表明，所合成的脂肪酰氨基酸酯均能在水油体系中分散，且具有较强的生物抗菌性，其中，0.01 mg油酸酰亮氨酸乙酯能有效地抑制金黄色葡萄球菌(菌数由2.0×10⁹ CFU/mL降至1.4×10⁷ CFU/mL)，而相同质量油酸酰酪氨酸甲酯则能抑制大肠杆菌(菌数由2.0×10⁹ CFU/mL降至1.8×10⁷ CFU/mL)。     

碳和氮代谢被抑制诱导雨生红球藻细胞内虾青素的合成

为研究雨生红球藻(Haematococcus pluvialis)合成虾青素的机理,文中分析了不同诱导条件下藻细胞内氮和碳代谢的变化。结果表明:强光照(HL)、添加乙酸钠(AA)、缺氮(NF)和缺磷(PF)都直接或间接地影响了雨生红球藻细胞内1,5-二磷酸核酮糖羧化酶(Rub isco)和硝酸还原酶(NR)的活性,导致2种酶的活性大幅度下降。只有当Rub isco和NR的活性降到非常低的水平时,藻细胞才开始合成虾青素。与此相反,对照(CK)中这2种酶的活性一直较高,但细胞内没有虾青素积累。由于Rub isco和NR是雨生红球藻碳代谢和氮代谢的关键酶,因此碳和氮代谢被抑制是诱导雨生红球藻合成虾青素的原因。     

Oxidative stability of soybean oils with altered fatty acid compositions

The oxidative stabilities of one canola oil and six soybean oils of various fatty acid compositions were compared in terms of peroxide values, conjugated dienoic acid values and sensory evaluations. Two of the soybean oils (Hardin and BSR 101) were from common commercial varieties. The other four soybean oils were from experimental lines developed in a mutation breeding program at Iowa State University that included A17 with 1.5% linolenate and 15.2% palmitate; A16 with 2% linolenate and 10.8% palmitate; A87-191039 with 2% linolenate and 29.6% oleate; and A6 with 27.5% stearate. Seed from the soybean genotypes was cold pressed. Crude canola oil was obtained without additives. All oils were refined, bleached and deodorized under laboratory conditions with no additives and stored at 60°C for 15 days. The A17, A16, A87-191039 and A6 oils were generally more stable to oxidation than the commercial soybean varieties and canola oil as evaluated by chemical and sensory tests. Canola oil was much less stable than Hardin and BSR 101 oils by both chemical and sensory tests. The peroxide values and flavor scores of oils were highly correlated with the initial amounts of linolenate (r=0.95, P=0.001). Flavor quality and flavor intensity had negative correlations with linolenate, (r=−0.89, P=0.007) and (r=−0.86, P=0.013), respectively.     

天然脂肪酸及其聚合物

简介天然脂肪酸的性质及国内外的生产、消耗水平；重点介绍一烯酸中的油酸的来源、古量、用途，还介绍天然脂肪酸聚合物二聚酸的结构、性质、生产工艺、品种、质量、用途、市场等。     

气相色谱法测定化妆品中脂肪酸含量

建立了气相色谱法检测化妆品中脂肪酸(十二酸、十四酸、十六酸、十八酸)。采用HP-5毛细管柱,研究脂肪酸甲酯化及气相程序升温的参数,得到了应用保留时间和峰面积对脂肪酸进行定性定量的方法。结果表明,此方法参数可以使化妆品中的脂肪酸得到很好分离,具有较高的准确性和重复性,线性相关系数均为1,测定结果与实际添加量的偏差在2%以内。     

脂肪酸甘油酯磺酸盐的合成

以α-磺酸脂肪酸甲酯和甘油为原料,经酯交换及中和反应合成了脂肪酸甘油酯磺酸盐。得到较佳的反应条件为:四氯化碳作溶剂,n(α-磺酸脂肪酸甲酯)∶n(甘油)=1∶5,75℃反应4 h,高效液相色谱分析α-磺酸脂肪酸甲酯的转化率可达66.33%。采用红外光谱和质谱确证了脂肪酸甘油酯磺酸盐的结构,结果表明,反应产物中除了含有单脂肪酸甘油酯磺酸盐外,还含有脂肪酸甲酯磺酸盐和二脂肪酸甘油酯磺酸盐。     

生物柴油在精细化学品领域的应用

论述了生物柴油(即脂肪酸甲酯)代替脂肪酸在制造精细化工品上的优势,并列举了生物柴油在表面活性剂工业、塑料助剂、醇酸树脂、皮革化学品上的应用。指出了用生物柴油代替脂肪酸具有成本低廉、工艺简化的优点,并可提高生物柴油的应用价值,具有广阔的应用前景。     

Digestibility of fatty acid monomers,dimers and polymers in the rat

This study was designed to determine digestibilities of fatty acid monomers, dimers and polymers as components of diets containing thermally oxidized oils. Male Wistar rats were fed semipurified diets supplemented with unheated, heated and a 1:1 mixture of unheated/heated olive oils at 6, 12 and 20% w/w of diet. In a 14-d experimental period, fecal lipids were extracted and analyzed by a combination of adsorption and high-performance size-exclusion chromatographies. Thus, it was possible to separate and quantitate five groups of fatty acids—nonpolar monomers, oxidized monomers, nonpolar dimers, oxidized dimers and polymers. Nonpolar fatty acid monomers showed high digestibilities, although significantly influenced by the alteration level of the dietary oil. The apparent absorption of oxidized fatty acid monomers averaged 76.6%. Among polymeric fatty acids, the lowest digestibilities were found for nonpolar dimers (10.9% on average), whereas oxidized dimers and polymers possessed higher apparent absorbability than expected, ranging from 22.7% to 49.6%. Chemical modifications prior to absorption, leading to less complex products, may have contributed to enhanced digestibility of polymers.     

Determination of vernolic acid content in the oil ofEuphorbia lagascae by gas and supercritical fluid chromatography

Determination of the content of vernolic acid (12,13-epoxy-9c-octadecenoic) in the oil ofEuphorbia lagascae has been performed by gas chromatography of the fatty acid methyl ester derivatives of the triacylglycerols in the oil and by supercritical fluid chromatography (SFC) of the raw oil and the fatty acid derivatives of the oil. The content of vernolic acid was found to be 55 wt%. The three methods were compared, and SFC analysis of the fatty acid derivatives was found to be the most accurate method.     

Simultaneous Determination of Free Fatty Acids and Esterified Fatty Acids in Rice Oil by Gas Chromatography

Free fatty acids (FFA) in crude rice oil were selectively and stoichiometrically derivatized to fatty acid N,N-dimethylamides (FADMA) by catalytic condensation at 45 °C, and then esterified fatty acids (eFA) were directly converted to fatty acid methyl esters (FAME) at 37 °C. The mixture of FADMA and FAME formed in a single test tube was injected into the capillary column of a gas chromatograph (GC). No mutual contamination occurred between FFA and eFA, and reliability of the method was confirmed by comparison between GC data obtained by this method and by a conventional isolation method. The advantages of the present method are that no FFA isolation procedures are required, the reactions proceed under mild temperature conditions, and FFA and eFA can be analyzed simultaneously by GC.     

Stabilisation of the Fatty Acid Decarboxylase from Chlorella variabilis by Caprylic Acid

The fatty acid photodecarboxylase from Chlorella variabilis NC64 A (CvFAP) catalyses the light-dependent decarboxylation of fatty acids. Photoinactivation of CvFAP still represents one of the major limitations of this interesting enzyme en route to practical application. In this study we demonstrate that the photostability of CvFAP can easily be improved by the administration of medium-chain length carboxylic acids such as caprylic acid indicating that the best way of maintaining CvFAP stability is ‘to keep the enzyme busy’.