Structural analysis of triacylglycerol fraction and some its sub-fractions from an eicosapentaenoic acid/docosahexaenoic acid dietary supplement

 Ag⁺- and RP-HPLC have been used to study the triacylglycerol fraction of a dietary supplement containing fish oil. The fatty acid (FA) distribution in the glycerol backbone of the triacylglycerol fraction was determined by stereospecific analysis. Eicosapentaenoic acid, the most abundant poly unsaturated FA, was predominantly located in the sn-3 position, while docosahexaenoic and docosapentaenoic acids were generally located in the sn-2 position. The nutritional significance of these findings is briefly discussed. Received: 18 February 1998 / Revised version: 25 June 1998     

RP-HPLC法测定水果中的蛇麻醇酯

应用反相高效液相色谱法(RP-HPLC)建立蛇麻醇酯简便的分析方法。分析条件为：色谱柱Nucleosil C18(250mm×4.6mm,5μm),流动相A为甲醇和水(甲醇:水=20:80),用体积分数50%的磷酸调pH值至3.2±0.05,流动相B为甲醇(含0.01%的磷酸),A:B=4:96,流速1.2mL/min,检测波长为210nm,柱温40℃。蛇麻醇酯的标准曲线为5～250μg/mL 7个治疗质量浓度梯度,y=4.6068x＋11.2640,R2=0.9992。精密度实验结果：连续5次进样,保留时间 RSD为0.2107%,峰面积的RSD为1.2843%;同一样品,在0～48h内9次进样,保留时间的RSD为0.3383%,峰面积的RSD为1.9737%。准确度实验结果：回收率为94.971%～101.964%,回收率的RSD为2.5825%。仪器的最低检出限为1.8886μg/mL。被测定的几种水果(青果、草莓、香蕉、巨峰葡萄、美国红提、番木瓜)中,以青果(干粉)中含量最高,达359μg/g以上。本研究建立的分析条件,能满足水果等样品中蛇麻醇酯定性定量分析的需要。     

A method for the determination of N-nitrosodiethanolamine in personal care products - collaboratively evaluated by the CTPA Nitrosamines Working Group

A procedure for the determination of N-nitrosodiethanolamine (NDELA) in personal care products was evaluated in collaborative studies by member organizations of the United Kingdom's Cosmetic Toiletry and Perfumery Association (CTPA) and LGC Limited, formerly known as the Laboratory of the Government Chemist (LGC). Samples were prepared depending on the matrix of the cosmetic product: aqueous samples were prepared by diluting in water followed by solid-phase extraction; emulsions, oils and solid materials were dissolved in dichloromethane and extracted with water. NDELA was separated from the sample matrix using reverse-phase liquid chromatography. The N-nitroso bond was cleaved by photolysis to give nitrite, which was colorimetrically quantified. The nitrite functional group reacted with sulphanilamide in an acid medium to form a diazonium ion which was then coupled with N-(1-naphthyl)ethylenediamine dihydrochloride according to the Griess reaction to give a purple-coloured azo dye that absorbed at 540 nm. Compared with other published methods for NDELA, the method described here is quick and easy to use. It has the required sensitivity and specificity, and can accurately and reliably quantify NDELA in a wide range of personal care product matrices.     

月桂酸甲酯乙氧基化物中的聚乙二醇和月桂酸甲酯的同时测定

使用C8键合硅胶色谱柱、示差折光检测器的反相液相色谱法同时测定了月桂酸甲酯乙氧基化物中的聚乙二醇和月桂酸甲酯的含量,通过优化流动相配比实现了月桂酸甲酯乙氧基化物同聚乙二醇和月桂酸甲酯的完全分离,方法简便快速,适用于产品的质量控制和工艺研究。     

Carboplatin liposomal nanoparticles: Preparation,characterization, and cytotoxicity effects on lung cancer in vitro environment

The study aimed to encapsulate anticancer drug carboplatin into liposomal nanoparticles by reverse-phase evaporation technique and evaluate its efficacy on lung cancer in vitro environment. Nanoparticles were characterized in terms of size, drug loading efficiency, drug retention capability, and cytotoxicity effects. Nanoscale particles with 67% drug encapsulation efficiency were prepared. Also, high retention capability (drug release equal to 25% after 72?h) of the nanodrug was confirmed. In addition, results of the nanodrug cytotoxicity indicated nanoparticles increased potency of the drug by approximately 90%. Findings of the study indicated liposome can be used for carboplatin delivery to lung cancer.     

Deformable liposomes by reverse-phase evaporation method for an enhanced skin delivery of (+)-catechin

Background: (+)-catechin, as the most common catechin isomer, is recognized to be an antioxidant which benefits the skin in many ways. The purpose of the present study was to prepare and evaluate a suitable liposomal delivery systems for (+)-catechin topical application.

Methods: In this study, catechin-loaded conventional liposomal delivery system, deformable conventional liposomal delivery system and deformable liposomes prepared by reverse-phase evaporation (REV) method were compared. The three systems were characterized for liposome particle size, zeta-potential, entrapment efficiency, drug release, permeability across porcine skin and catechin deposition in the skin.

Results: It was revealed that the size of deformable conventional liposomes before freeze-drying and deformable REV liposomes after freeze-drying range from 335.6?±?71.7?nm to 551.1?±?53.4?nm, respectively, which were considered to be suitable for skin delivery. The deformable REV liposomes had a higher aqueous volume and thus were able to entrap greater amounts of hydrophilic (+)-catechin (50.0?±?5.9%) compared to conventional (30.0?±?3.8%) and deformable conventional liposomes (36.1?±?4.6%). All liposomal formulations exhibited a prolonged catechin release. Compared to deformable liposomes, the REV deformable liposomes showed a significantly better deposition of (+)-catechin while catechin solution did not permeate into the porcine ear skin.

Conclusion: Among all formulations studied, deformable REV liposomes were considered to be favorable for catechin topical delivery.     

Effects of a cross-linking enzyme on the protein composition,mechanical properties,and microstructure of Chinese-style noodles

Flours, representing the three major classes of Canadian wheat used for the production of noodles, were processed into fresh, Chinese-style, yellow alkaline noodles (YAN) with and without (1 w/w, fwb) the cross-linking enzyme transglutaminase (TG). The flours, YAN-TG and YAN + TG were sequentially extracted to remove albumins and globulins, followed by a series of 50% propanol extractions (±4% DTT) and 50% propanol +4% DTT +1% acetic acid to ensure removal of all extractable gliadin and glutenin components. Reverse-phase (RP) HPLC analyses of all propanol extracts were performed and the change in protein composition and distribution reported. Raw YAN, ±TG, were simultaneously evaluated for their fundamental rheological characteristics using ultrasound and stress relaxation testing. Significant changes in the distribution of protein within the various propanol extracts were observed when the flours were processed into YAN ± TG. The amount of unextractable protein increased by as much as ∼3-fold in YAN + TG, and ∼2-fold in YAN-TG, relative to that present in their respective source flour. Significant differences were observed within and between the YAN variety samples for the longitudinal modulus and the tan delta, when processed ±TG. Significant correlations (p = 0.05) were observed between protein composition, ultrasonic and stress relaxation parameters.     

熊果苷脂质体的制备研究

采用逆相蒸发制备熊果苷脂质体,研究了熊果苷脂质体配方中不同成分的比例、水合介质及高压挤压工艺对脂质体包封率的影响。结果表明:较佳的配方组成为大豆磷脂PC、胆固醇、熊果苷的质量比为400∶34∶136;投药比越大,包封率越低;较佳的水合介质是葡萄糖溶液。高压挤压工艺不利于得到较高包封率的熊果苷脂质体。     

高效液相色谱法测定亚甲基二磷酸含量

采用反相高效液相色谱法/蒸发光散射检测器（ELSD）研究了亚甲基二磷酸含量测定及相关物质的分析方法。以Symmetry C8为固定相,V（30 mmol/L正戊胺（用乙酸调节pH 5.0））∶V（甲醇）=98∶2为流动相,流速为1 mL/min,蒸发光散射检测器检测亚甲基二磷酸对照品溶液。在该条件下,亚甲基二磷酸及相关物质（包括合成过程中残留的亚磷酸及氧化分解产物磷酸）的分离良好。方法的线性范围在600～4 000 mg/L,线性回归方程为：lgA=1.943 6 lgC+16.212,r=0.999 6,检出限为200 mg/L,回收率在98%～102%,适用于亚甲基二磷酸原料的常规检测及有关物质的检查。     

邻苯二甲醛柱前衍生化时间对反相高效液相色谱法测定稻米氨基酸含量的影响

目的 确定反相高效液相色谱法(reversed-phase high performance liquid chromatography,RP-HPLC)测定稻米氨基酸含量最适柱前衍生化时间.方法 以氨基酸标准品以及稻米氨基酸提取物为对象,对柱前衍生化时间与氨基酸检测结果之间的关系进行研究.结果 邻苯二甲醛(O-pht...