液相色谱/电喷雾质谱测定柑桔中的柠檬苦素类似物配糖体

 利用液相色谱 /电喷雾质谱联用技术对柚皮中的柠檬苦素类似物配糖体进行了定向分析 ,在柚皮的乙醇提取物中检测出奥巴叩酮配糖体和诺米林配糖体。利用制备液相色谱对这两种柠檬苦素类似物配糖体进行纯化 ,并用核磁共振对其结构进行鉴定。测定结果表明 ,液质联用法不需标样即可对柑桔中的柠檬苦素类似物配糖体进行定性分析。方法准确、快速、简便。     

环肽配糖体的二维核磁共振谱研究

用600MHz超导核磁共振仪测定了两个具有抗癌活性环肽配糖体RY-2和RY-3的TOCSY, HMQC, HMBC和ROESY谱图, 并正确地对分子RY-2和RY-3的氢谱和碳谱进行了归属。同时订正分子RY-3中糖的连接位置。     

高效分离糖及糖和糖甙的α-、β-差向异构体的新型柱——β-环糊精化学键合相柱

]β-环糊精化学键合相色谱柱用于分离糖、糖醇,糖与糖甙的α-和β-差向异构体有好的分离效果。在室温,常规洗脱分离糖,大多数不存在差向异构体的分离。分离一些糖的差向异构体,在0℃有更好的效果。多种溶剂体系,如乙腈/水、丙酮/水,乙酸乙酯/甲醇/水、乙醇/正己烷等都可有好的分离效果。所有的分离都为正相体系。柱效和柱的稳定性均很好。如果使用uv检测器的低波长端（如195nm,以乙腈/水为移动相,不仅可用之检测糖,还可作梯度洗脱。     

生物质糖一步氢解制备二元醇的研究进展

以生物质糖为原料一步氢解制备二元醇的工艺路线不仅可以替代石油等不可再生资源实现可再生资源的合理有效利用,而且符合中国“碳减排、碳中和”的战略目标,是一条新型的绿色可持续发展路线。本文综述了生物质糖一步氢解制备二元醇工艺的催化剂设计研发、催化机理、氢解反应路径以及供氢方式和供氢体的选择等,提出了目前该工艺中亟待解决的问题和面临的挑战,展望了该工艺路线的发展方向。     

体积流量法配制多组分气体混合物

建立了一种简便、价廉的多组分气体混合物的动态制备方法并设计和组装了动态体积配气仪。用气相色谱对动态体积配气仪配制的混合气体进行分析并与其理论配比相对照，结果表明，该方法的准确性、稳定性和重复性是令人满意的。此外，按照配气的过程对影响配气精度的因素进行了理论分析。分析表明，气流流速的稳定性、流速测定的准确性和气路条件的一致性是决定配气效果的主要因素。     

液相色谱-电喷雾电离质谱与电子轰击质谱联用筛选百合中的甾体皂甙

 利用高效液相色谱 电喷雾电离质谱联用仪 (HPLC/ESI MS)、电子轰击质谱 (EI MS)和半制备型高效液相色谱 ,从卷丹百合中筛选出了两种甾体皂甙 ,其中一种为含有 3个糖基与提果皂甙元的甾体皂甙 ,另一种为含有 3个糖基和薯蓣皂甙元的甾体皂甙。结果表明 :在线的HPLC/ESI MS能够准确快速地提供糖甙类化合物的分子质量和糖链部分的有益信息 ,但对甙元部分提供的信息极少 ;离线的EI MS只需极少量 (1mg～ 2mg)的纯品就能准确地提供甙元部分的有益信息 ,但很难获得糖甙的分子离子峰与糖链部分的信息 ,两者有机地结合起来能快速地从植物中筛选甾体皂甙。     

马铃薯中配糖生物碱总量测定方法研究

采用四氢呋喃：水：乙腈：乙酸（５０：３０：２０：１，Ｖ／Ｖ）混合 液提取马铃薯中总配糖生物碱。离心后，上清液在酸性条件下超声波处理，氨水调节ＰＨ１０．５，沸水浴蒸干，用ＰＨ１０．５的氨水洗涤残留笺，离心。     

聚甲基丙烯酸葡萄糖酯及聚甲基丙烯酸纤维二糖酯高效液相色谱手性固定相的性能测评

首先合成了甲基丙烯酸葡萄糖酯和甲基丙烯酸纤维二糖酯,然后通过甲基丙烯酸-3-(三甲氧基硅基)丙酯分别聚合在硅胶上,并将其作为高效液相色谱手性固定相。分别以正己烷-异丙醇(体积比为90:10)、正己烷-异丙醇-三乙胺(体积比为90:10:0.2)和正己烷-异丙醇-三氟乙酸(体积比为90:10:0.2)溶液作为流动相,对15种包含醇类、胺类、酰胺类和酮类的外消旋体化合物进行手性拆分。拆分结果表明,葡萄糖和纤维二糖聚合物固定相对大多数醇类和胺类以及部分酰胺类和酮类外消旋体化合物有较好的手性识别能力,并且二者的手性识别能力还具有一定的互补性。该研究表明,单糖和二糖聚合物固定相可成为一类新型的高效液相色谱手性固定相。     

食品中降解糖的高灵敏、高选择性的检测方法

本文使用岛津公司开发的,以精氨酸为衍生剂的降解糖柱后衍生荧光检测系统,并选择配位体交换色谱法为分离手段,获得了6种降解糖的线性关系和检出限。本法重现性较好。利用该法测定了酱菜汁中的各种糖组分的含量,分析结果满意。     

离线二维色谱结合糖苷外切酶酶解用于IgG与人血清糖蛋白中N-糖链的结构表征

基于离线二维色谱和糖苷外切酶分析,建立了一种有效、可靠的糖蛋白N-糖链的结构鉴定方法。首先采用弱阴离子交换色谱实现不同唾液酸程度糖链的制备,随后将激光诱导毛细管电泳(CE-LIF)与糖苷外切酶相结合进行糖链结构鉴定。将分离制备后的糖链荧光标记后,进行自上而下的消化(top-down digestion)以及自下而上的结构归属(bottom-up identification),共检测到IgG中的18种糖型。将上述策略进一步应用于人血清中N-糖链的分析,发现不同唾液酸化程度糖链的相对量为S1∶S2∶S3∶S4=4.7∶20.9∶6∶1。结果表明,人血清中高丰度的中性糖链与IgG的中性糖链结构非常相似,而血清中含量最丰富的是二唾液化两天线的N-糖型FA2G2S2。该方法在糖蛋白N-糖链的结构表征中具有一定的应用潜力。     

Screening for limonoid glucosides in Citrus tangerina (Tanaka) Tseng by high-performance liquid chromatography-electrospray ionization mass spectrometry

A screening method for limonoid glucosides in the peel of Citrus tangerina (Tanaka) Tseng, which utilizes high-performance liquid chromatography (HPLC) with diode-array detection and interfaced to electrospray ionization mass spectrometry, has been developed. In this way, the UV-Vis spectra and the mass spectra indicate the presence of limonoid glucosides without the necessity of isolating the individual compounds. Two major limonoid glucosides--obacunone glucoside (OG) and nomilin glucoside (NG)--were identified in the methanol extract of the peel. The two limonoid glucosides were taken as the target and isolated by means of preparative HPLC on a C18 reversed-phase column with an acidic acetonitrile-water mobile phase. The structures of OG and NG were further confirmed by nuclear magnetic resonance spectrometry.     

Simultaneous separation and identification of limonoids from citrus using liquid chromatography-collision-induced dissociation mass spectra

Limonoids are considered as potential cancer chemopreventive agents and are widely distributed in the Citrus genus as aglycones and glucosides. In the present study, reversed-phase HPLC coupled with CID mass spectra was developed for the simultaneous separation and identification of aglycones and glucosides of limonoids from citrus. Five aglycones such as limonin, deacetyl nomilin, ichangin, isolimonoic acid and nomilin were identified by positive ion CID MS/MS, whereas five glucosides, viz. limonin glucoside, isoobacunoic acid glucoside, obacunone glucoside, deacetyl nomilinic acid glucoside and nomilinic acid glucoside were analyzed by negative ion CID mass spectra. The developed method was successfully applied to complex citrus samples for the separation and identification of aglycones and glucosides. Citrus seeds were extracted with methanol and partially purified and analyzed by LC-CID mass spectra. The separation was achieved by C-18 column; eight limonoids were identified by comparing the retention times and mass spectral fragmentation. To the best of our knowledge, this is the first report on the identification of citrus limonoids using CID technique.     

Dye sensitized luminescent europium nanoparticles and its time-resolved fluorometric assay for DNA

High performance liquid chromatography (HPLC) method has been developed for simultaneous quantification of limonoid aglycones and glucosides on a reversed phase C₁₈ column using a binary solvent system, coupled with diode array detector. Seven limonoids such as limonin, nomilin, isolimonic acid, ichangin, isoobacunoic acid, limonin 17-β-d glucopyranoside and deacetyl nomilinic acid 17-β-d glucopyranoside were separated and detected at 210 nm. Furthermore, limonoids were separated, identified and quantified in four varieties of citrus fruits and seeds using developed method. Limonin and limonin glucoside were found to be the predominant limonoid aglycone and glucoside, respectively, in all tested samples. The sensitivity of the method was found to be 0.25–0.50 μg for tested limonoids.     

反相高效液相色谱法制备纯化大豆异黄酮糖苷

利用制备高效液相色谱法从大豆总异黄酮提取物中制备出了3种大豆异黄酮糖苷。在Nova-Pak HR C18色谱柱(100 mm×25 mm i.d.,6 μm)上,以甲醇-体积分数为0.1%的乙酸水溶液(体积比为23∶77)为流动相,流速为20 mL/min,采用 等度洗脱方式,制备了3种大豆异黄酮糖苷,经质谱分析,确认它们分别为大豆苷、黄豆苷和染料木苷。高效液相色谱分析 表明,所制备的3种化合物的纯度均达到了99%以上。     

Application of preparative reversed-phase high-performance liquid chromatography to the isolation of insulin-like growth factor II from human serum

Substantially purified insulin-like growth factor II (IGF-II) was prepared from human serum. Initial enrichment using ion-exchange chromatography on DEAE Sephadex A50, followed by gel permeation chromatography on Sephadex G-75 in 1% formic acid produced material suitable for application to a preparative reversed-phase high-performance liquid chromatographic (HPLC) column containing LiChroprep RP-18. The latter step gave about 90-fold purification with a recovery of about 70% IGF-II bio-activity. Finally, a small reversed-phase HPLC column achieved a 17-fold purification with similar yield of activity. Overall, the four steps gave IGF-II of about 90% purity in yield of 12%.     

Separation of human glycoprotein hormones and their subunits by reversed-phase liquid chromatography

Separation of human pituitary follicle-stimulating hormone (FSH), luteinizing hormone (LH) and thyroid-stimulating hormone (TSH) was effected on a micro-scale by reversed-phase high-performance liquid chromatography (HPLC) on a SynChropak C1 column in series with a Vydac C4 column using a linear gradient of acetonitrile in 0.1 M triethylamine phosphate buffer at pH 6.5. Chromatography on the C4 column alone caused partial dissociation of FSH into its subunits, whereas LH and TSH remained intact. Good yields of the separated subunits were obtained after prior dissociation of each hormone, and the results show that reversed-phase HPLC is useful for the analytical and preparative separation of these structurally related hormones and their subunits.     

Isolation and preparative purification of microcystin variants

Preparative reversed-phase liquid chromatography was successfully used to purify two microcystins (microcystin LR and microcystin LA) from a cyanobacterial process waste. The separation protocol involved extraction of lyophilized cells by methanol, isolation and concentration by solid-phase extraction, and purification by reversed-phase HPLC. Milligram-level loading of microcystins was obtained on a solid-phase extraction cartridge packed with 0.5 g of C18 stationary phase. The separations were first carried out on an analytical column and then scaled-up to a preparative column. The microcystins were quantified by HPLC and enzyme-linked immunosorbent assay. A method to remove microcystins rapidly and economically from the cyanobacterial process waste is also described.     

反相高效液相色谱法制备松果菊苷标准品

 利用反相制备高效液相色谱结合溶剂萃取、大孔吸附树脂柱色谱和葡聚糖凝胶LH 2 0柱色谱方法 ,从管花肉苁蓉的乙醇提取物中纯化制备了苯乙醇苷类化合物松果菊苷的标准品 ,纯度达到 98%以上。方法操作简便 ,重现性好 ,可用于松果菊苷及其他苯乙醇苷类化合物的大量制备。     

Simultaneous determination of serum uremic toxins, cations and anions and urea determination by post-column colorimetry using immobilized enzyme

A column-switching method which combines ion-exchange and ion-pair reversed-phase chromatography was developed for the determination of serum uremic toxins, cations and anions. Serum urea, which was poorly separated by reversed-phase chromatography, was analyzed using an immobilized-urease column and detected by post-column colorimetry. Apart from the simultaneous analysis, anion analysis using ion-pair reversed-phase chromatography on an ODS column was also developed. The origin of the system peak observed in anion analysis with an eluent containing phthalate has been clarified.