5种贝类脂肪含量及脂肪酸组成研究

 用氯仿 甲醇法测定了广州海鲜市场上棕带仙女蛤、波纹巴非蛤、文蛤、栉孔扇贝和园华扇贝等 5种贝类的脂肪含量 ,并用GC MS法测定了它们的脂肪酸组成。 5种贝类鉴定出的脂肪酸都在 99% (质量分数 )以上。它们的脂肪含量都大于 1% (质量分数 ) ,园华扇贝的脂肪含量最高。它们的ω 3多不饱和脂肪酸与ω 6多不饱和脂肪酸含量的比值基本上都大于 2。两种扇贝的廿碳五烯酸 (EPA)和廿二碳六烯酸 (DHA)含量都比较高。分析结果表明 ,园华扇贝不仅脂肪含量高 ,而且EPA与DHA的含量也比较高 ,是EPA和DHA理想的提取原料     

体积排阻高效液相色谱-电感耦合等离子体质谱法测定海产贝类中镉的形态

运用体积排阻高效液相色谱-电感耦合等离子体质谱联用技术(SEC-HPLC-ICP-MS)分析了高镉积累扇贝和低镉积累菲律宾蛤仔中镉的存在形态,并结合体外全仿生消化技术,研究了在唾液、胃、肠无机物和有机物(含消化酶)作用下,扇贝和菲律宾蛤仔中镉的主要存在形态.结果发现:扇贝中Cd总量约为菲律宾蛤仔的10倍;在扇贝中检测到3种Cd形态:金属硫蛋白(MT)-Cd、谷胱甘肽(GSH) Cd和半胱氨酸(Cys)-Cd;在菲律宾蛤仔中检测到2种Cd形态:MT-Cd和GSH-Cd;以峰面积作参考进行比较,扇贝中MT-Cd和GSH-Cd含量分别约为菲律宾蛤仔的5 6和2.0倍.结合体外全仿生模型发现,在扇贝胃全仿生提取液中,检测到1种未知小分子有机镉形态(Cd-X),在扇贝肠全仿生提取液中检测到4种Cd形态,其中MT-Cd是主要形态;而在菲律宾蛤仔胃、肠全仿生提取液中均仅检测到1种未知小分子有机态镉(Cd-X).本实验证明贝类中的MT-Cd,GSH-Cd,Cys-Cd中络合的Cd在生物体胃肠消化液作用下会发生解离.     

叶菜型甘薯茎尖中微量元素和氨基酸的含量分析

采用等离子体发射光谱法测定了叶菜型甘薯茎尖中K、Ca、Mg、Fe、Zn、Cu、Se等7种微量元素的含量,氨基酸分析仪测定了18种氨基酸的含量。结果表明,与其它12种叶菜类蔬菜相比较,叶菜型甘薯茎尖中K、Ca、Se含量较高;含有18种氨基酸,人体必需的氨基酸种类齐全,含量较高的氨基酸是天冬氨酸、谷氨酸、亮氨酸;高Se是叶菜型甘薯茎尖的显著特点。为探讨叶菜型甘薯茎尖中微量元素和氨基酸与保健功能之间的关系提供了有用的数据。     

不同生长期中菘蓝多糖和氨基酸含量变化规律研究

分别采用苯酚-硫酸法、茚三酮比色法测定菘蓝中总多糖和游离总氨基酸含量.分析结果表明,在不同的生长季节,根中游离氨基酸、总多糖含量逐月上升,均在11月份含量最高;叶中游离氨基酸含量先上升,后下降,以8月份和10月份含量较高,总多糖含量逐月上升,在十一月份含量最高.菘蓝生长过程中,根和叶中的总多糖和游离总氨基酸含量随着发育进程而发生变化.这一变化规律为中药的规范化种植(GAP)提供了实验依据.     

三裂叶蟛蜞菊中氨基酸成分和矿物元素的分析

为更好地开发利用蟛蜞菊这一中草药资源,采用氨基酸分析仪和原子吸收光谱仪测定了游离氨基酸的含量和矿物元素的含量。结果表明,蟛蜞菊中富含多种成分的氨基酸,其中谷氨酸、天门冬氨酸、亮氨酸含量较高,且含有7种人体必需的氨基酸;还含有丰富的钙、镁、铁、锰、锌、铜和硒等矿物元素;蟛蜞菊中高含量的氨基酸成分及矿物元素与其多种生理、药理活性作用密切相关。     

反相高效液相色谱用于寄生虫中氨基酸含量的测定

 为了对寄生虫病进行有效的防治 ,采用柱前衍生、反相高效液相色谱分离、紫外吸收定量法对中国 7个地区马来丝虫及马来丝虫幼虫氨基酸的组成和含量进行了测定。结果表明 :不同地区的马来丝虫中各氨基酸的含量存在着一定的差别 ,幼虫的氨基酸含量明显低于成虫的相应氨基酸含量。此方法简便、准确 ,在研究寄生虫的种内分化、种下分类和生长、发育、代谢等生命活动方面具有重要的意义。     

微波辅助萃取-GC/MS联用分析竹子中氨基酸

建立了微波辅助萃取-GC/MS联用测定竹子中谷氨酸、天冬氨酸和苯丙氨酸等10种氨基酸的分析方法, 优化了微波辅助萃取条件, 方法的线性范围在0.100～100 μg/mL之间, 检出限在0.0098～0.36 μg/mL之间, RSD为4.1%～9.7%, 回收率在84.3%～118%之间. 分析了4种不同产地、竹龄竹子的竹叶、竹枝和竹沥中氨基酸含量. 结果表明, 不同竹种、产地及竹龄的竹子中氨基酸总量有较大差异;相同竹种其竹沥中氨基酸含量显著高于竹叶及竹枝中氨基酸含量.     

大亚湾沉积物中氨基酸的垂直分布——沉积物柱样W0中的水解氨基酸

测定了采自大亚湾近岸海域的一个长60cm的沉积物柱样W0中15种水解氨基酸的含量；结果表明，15种水解氨基酸含量均随深度而下降，其中苏氨酸、丝氨酸、甘氨酸、丙氨酸、精氨酸、缬氨酸、苯丙氨酸、亮氨酸、异亮氨酸的含量以及水解氨基酸总量随深度的变化可用指数方程c＝c0e^-kx加以描述；天冬氨酸、谷氨酸、丝氨酸、甘氨酸、丙氨酸和缬氨酸是大亚湾沉积物中最丰富的氨基酸。     

高效液相色谱法测定味精厂发酵渣中的氨基酸

建立了37种标准氨基酸混合液的分离方法,并以此分离条件测定发酵渣和大米中各种氨基酸含量,测定结果表明发酵渣中氨基酸含量是大米的六倍以上,可提纯作为营养品。 本法系离子交换色谱法,使氨基酸混合液通过锂柱,控制不同pH值的流动相进行梯度淋洗,使各种氨基酸分离,柱后依序加入次氯酸钠     

氨基酸-稳定同位素稀释质谱法用于合成肽段准确含量分析

建立了氨基酸同位素稀释液相色谱-串联质谱法准确测定合成肽段绝对含量的方法。实验中对合成肽段的纯度进行了表征,色谱纯度表征结果为99%以上,质谱纯度为90%以上。在肽段溶液中加入13C标记的氨基酸后进行酸溶液水解时间的优化,水解后的氨基酸直接经液相色谱分离和质谱检测,结果表明肽段中的被测氨基酸在150 ℃、6 mol/L HCl溶液水解4～6 h就可以达到水解平衡。每个肽段选择两个或两个以上的被测氨基酸,测得随机选择的5种合成肽段的绝对含量为62.07%～88.18%,测定结果的相对标准偏差小于8%,相对误差小于5%,均满足定量要求。除常用的被测氨基酸苯丙氨酸、缬氨酸、异亮氨酸外,还考察了选择赖氨酸和精氨酸作为被测氨基酸的可行性,实验结果表明增加精氨酸为被测氨基酸是可行的,从而进一步增加了方法的普适性。该方法的建立避免了色谱法定量时氨基酸衍生化处理带来的副反应影响及操作繁琐等问题,提高了肽段含量测定的准确度和精密度,为肽段含量的准确测定提供了一种新的方法。     

宝日希勒褐煤在合成气与复合溶剂系统下的液化性能研究

在合成气（CO+H₂）与复合溶剂（水+有机溶剂）液化系统下研究了气氛、温度、催化剂类型对宝日希勒褐煤转化率、油气水产率和CO转化率等液化特征的影响,从而探讨其液化性能。结果表明,在高含水复合溶剂系统中,合成气气氛、反应温度430-450℃适宜宝日希勒褐煤液化转化,转化率可达到81.15%,油气水产率达到71.53%。该液化系统下,含铁、碱和硫复合型催化剂能有效地提高液化转化率和油气水产率,在430℃催化液化下褐煤转化率达92.27%,油气水产率达79.39%。该催化剂有效促进了煤中大分子的裂解和系统中水煤气变换反应进程,沥青质减少,油含量增多。液化油中多环芳烃衍生物在催化液化过程中向单环芳烃衍生物和烷烯烃转化,分子量降低,提高了油品质量。     

生物光化学

生物光化学研究光在动植物体内所引起的生化现象。例如:经过各种不同波长的光辐照后的生命现象,生长规律,某些生理和病理过程,疾病的产生和治疗机理,细胞的辐射损伤和自然防御,以及光合色素在生物进化中的作用等。本文就光引起的现象:视觉、生物钟(光周期性)、植物的光合作用、辐射损伤及其修复、牛皮癣的治疗、新生儿黄疸病的治疗机理,以及光合色素——藻胆蛋白等七种现象,做了综述性的介绍。     

三唑类药物研究新进展

三唑类化合物作为药物广泛应用于临床,是目前药物研究开发的重点领域之一．越来越多的高活性、低毒性、不良反应少、多药耐药性小、生物利用率高、药代动力学性质好、药物靶向性强、给药方式多样化、广谱、高疗效的三唑类化合物作为候选药物或药物用于临床医治多种疾病,显示出了三唑类化合物在医药领域的巨大开发价值和潜在的宽广应用．本文结合自己的工作,参考国内外近五年文献系统地综述了三唑类化合物作为药物在整个医药领域的研究与开发近况,包括抗真菌、抗细菌、抗结核、抗癌、抗病毒、抗炎镇痛、抗惊厥等,并展望其发展趋势与前景．希望该评论有助于为高活性低毒性三唑类医药合理设计提供新思路．     

冰片及其酯/酰胺类衍生物的合成和活性研究进展

冰片是重要的芳香开窍类中药,具有开窍醒神,清热止痛等功效,常被作为佐药与其他中药配伍使用。目前,冰片及其衍生物广泛用于医药、农药、化工及香料领域,市场前景好,研究和开发价值高。本文对天然冰片、合成冰片及其酯/酰胺类衍生物的主要合成方法和生物活性方面进行了系统总结,并对冰片酯类衍生物未来的研究方向进行了展望,以期为冰片及其酯/酰胺类衍生物的进一步的研究提供有益参考。     

石墨烯纤维：制备、性能与应用

石墨烯纤维是一种由石墨烯片层紧密有序排列而成的一维宏观组装材料。通过合理的结构设计和可控制备,石墨烯纤维能够将石墨烯在微观尺度的优异性能有效传递至宏观尺度,展现出优异的力学、电学、热学等性能,从而应用于功能织物、传感、能源等领域。目前,石墨烯纤维主要通过湿法纺丝、限域水热组装等方法制备得到,其性能可以通过对材料体系和制备工艺的优化而进一步提升。本文首先介绍了石墨烯纤维的制备方法,然后详细阐述了石墨烯纤维的性能,讨论了其性能提升策略,并总结了石墨烯纤维的应用,最后对石墨烯纤维的未来发展、挑战和前景进行了展望。     

Monitoring of pesticide residues in Riyadh dates by SFE,MSE, SFC,and GC techniques

In the present work, simple and rapid extraction and analysis techniques of insecticide (OCPs, OPPs, pyrethroids), fungicide, acaricide, and herbicide residues in three cultivars’ of date fruits viz., Khalas, Sukkari, Nabout Seif and their seeds have been applied. The date cultivars were collected from eight local markets of Riyadh, KSA. The extraction of pesticide residues from the three varieties of date samples was conducted by rapid and new extraction techniques, Supercritical Fluid Extraction (SFE) and Microwave Solvent Extraction (MSE). The analysis was performed, without clean-up, by Supercritical Fluid Chromatography (SFC) and Gas Chromatography (GC) using different detectors. The results showed that the SFE, MSE, SFC and GC techniques are clearly faster, more sensitive and more cost effective than conventional methods. The recovery efficiency of SFE and MSE was 99% and 97%, respectively. The recoveries, MDL (Minimum Detection Limit) and repeatability achieved in this study meet the standards set for tolerance level monitoring of these pesticides. The mean levels of some tested residues of pyrethroids, herbicides, and fungicides in dates and their seeds are below the MRL (Maximum Residue Level). However, lindane (BHC gamma isomer), dieldrin, dimethoate, chlorpyrifos and all tested acaricide residues in date fruit samples exceeded the MRLs indicating a hazardous trend in the date palm cultivation. The data also showed a higher concentration of OP dimethoate in the date seeds, which is sometimes, used as animal feed. The present results provide important information on the current contamination status of the date fruits in Riyadh markets and point to the action needed for controlling the excessive application of pesticides. This study is the first monitoring and screening of pesticide residues of 6 groups in Saudi Arabian dates.     

Enzyme Mimics: Advances and Applications

Enzyme mimics or artificial enzymes are a class of catalysts that have been actively pursued for decades and have heralded much interest as potentially viable alternatives to natural enzymes. Aside from having catalytic activities similar to their natural counterparts, enzyme mimics have the desired advantages of tunable structures and catalytic efficiencies, excellent tolerance to experimental conditions, lower cost, and purely synthetic routes to their preparation. Although still in the midst of development, impressive advances have already been made. Enzyme mimics have shown immense potential in the catalysis of a wide range of chemical and biological reactions, the development of chemical and biological sensing and anti‐biofouling systems, and the production of pharmaceuticals and clean fuels. This Review concerns the development of various types of enzyme mimics, namely polymeric and dendrimeric, supramolecular, nanoparticulate and proteinic enzyme mimics, with an emphasis on their synthesis, catalytic properties and technical applications. It provides an introduction to enzyme mimics and a comprehensive summary of the advances and current standings of their applications, and seeks to inspire researchers to perfect the design and synthesis of enzyme mimics and to tailor their functionality for a much wider range of applications.     

Synthesis,structure, and function of internally functionalized dendrimers

The past three decades have witnessed an exponential increase in the structural diversity and applications of dendrimers, spanning across drug delivery and diagnostics, protein, and enzyme mimicry, solubility enhancement, coatings, light harvesting, and catalysis. The dendrimer community has recently focused on internally functionalized dendrimers (IFDs) owing to their advanced design and functionality. The synthesis of IFDs relies on advanced orthogonal chemistries and/or (de)protection schemes, as well as careful purification to minimize polydispersity of composition and molecular weight. The studies published on IFDs, however, lay scattered across the chemical literature, and a comprehensive presentation of structural rationale, synthetic procedures, and technologically relevant applications is missing. To address this need, this review presents a comprehensive collection and discussion of all available studies on IFDs, detailing their methods of synthesis and their structure–function correlations. The wide variety of internal functionalities, including hydroxyl, amine, carboxylic acid, allyl, alkyne, and imidazole groups, enables myriad applications in biochemistry, chemical and biomedical engineering, and material science. Particular focus is given to IFDs that are amenable to modular synthetic strategies, which promote higher synthetic yield and scalability, and therefore possess stronger translational and commercial potential. As such, this review guides research groups pursuing the difficult task of IFD rational design and synthesis providing them a concise roadmap to their mission.     

Tautomeric and conformational isomerism of natural hydroxyanthraquinones

Natural 1,5-di-, 1,4,5-tri-, and 1,4,5,8-tetrahydroxyanthraquinones and their anions and metal complexes were shown to be equilibrium mixtures of tautomers and conformers using quantum-chemical and correlation analysis of elecronic absorption spectra. Solvent effects, ionization, complexation, and the introduction and substitution of substituents were accompanied by shifts of tautomeric and conformational equilibria that determine the color of the compounds. __________ Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 224–229, May–June, 2006.     

液体弹珠：制备策略、物理性质及应用探索

Liquid marbles (LMs) are liquid droplets coated with a layer of lyophobic particles at the air-liquid interface. Since the pioneering work by Aussillous et al. in 2001, LMs have attracted significant attention owing to their facile fabrication, flexibility in the choice of the constituent particles and liquids, intriguing properties such as non-wetting and non-adhesive nature, satisfactory elasticity and stability, as well as promising applications in microfluidics, sensors, controlled release, and microreactors. The classical strategy for the preparation of LMs involves rolling a small volume of a droplet on a lyophobic powder bed for complete encapsulation of the liquid by the particles. In addition, various innovative methods, including electrostatic and coalescent approaches, have been developed for preparing special LMs with a complicated structure or morphology. Diverse materials such as water, surfactant solutions, liquid metals, reagents, blood, and even viscous adhesives have been employed as the internal liquid for the fabrication of LMs. Theoretically, any particulates such as lycopodium, polytetrafluoroethylene, Fe₃O₄, SiO₂, and graphite grains can be employed as the outer coating, but they are usually required to be lyophobic with sizes of less than hundreds of microns. The unique structure of the particle-covered droplet and the dual solid-liquid characteristics endow LMs with some unique and interesting properties, especially the non-wetting and non-adhesive nature. As the lyophobic coating particles restrain the internal liquid from contacting the substrate, LMs can move easily across either solid or liquid surfaces, neither wetting the substrate nor contaminating the internal liquid. An equally fascinating property of LMs is their satisfactory stability, which is necessary for most of their applications. The high stability of LMs stems from the protection of the coating powders and is embodied in both good mechanical stability (remaining intact after being released from a certain height or under a certain compression) and long lifetime (greatly suppressing the evaporation of the internal liquid). These extraordinary properties make LMs promising candidates for use in multitudinous fields, especially droplet microfluidics and microreactors. The potential application of LMs in microfluidics is ascribed to their non-wetting, non-adhesive nature and other features such as an ability to float on a liquid surface, coalescence, split, a small force of rolling friction, and response to external forces. Notably, LMs hold great promise for applications in microreactions, because they can create a confined reaction microenvironment, minimize reagent usage, facilitate unhindered gas exchange between the internal liquid medium and the surrounding environment, and allow the entry/exit of the reactants/products. We herein review the recent advances in LMs, such as manufacturing techniques, formation mechanisms, physical properties, and emerging applications. In particular, much attention is paid to the factors affecting the stability of LMs and the potential strategies to increase their stability. Moreover, this review discusses the challenges in the future development of LMs, suggests several possible ways of addressing these challenges, and forecasts the future development directions. We believe that this review can help researchers gain a better understanding of LMs and promote their further advances.