Direct Obtention of Pure Compounds from Crude Plant Extracts by Preparative Liquid Chromatography

It has been possible to submit the crude hexane extract of the barks of a medicinal plant directly to preparative liquid chromatography. A two step solvent elution gave 6 peaks, four of which readily afforded crystalline material. The entire process required 2–3 hours whereas conventional chromatography required ca. 2 weeks.     

The Preparative HPLC Isolation and Identification of Phospholipids from Soy Lecithin

Abstract

Lecithins are a constituent of all living membranes. While lecithins are found in both plants and animals, the specific fatty acid subunits vary considerably between plants and animals. The lecithins of plant origin are chiefly derived from soy but other vegetable phospholipids are also used. World consumption of these compounds was estimated @ over 100,000 tons in 1981 (1) with growth expected each year.     

Isolation of Sesquiterpene Lactones and the Antioxidant and Anticancer Activities of Crude Extracts from Cyanthillium cinereum

Chemistry of Natural Compounds - Three sesquiterpene lactones has been isolated from Cyanthillium cinereum (L.) H. Rob. by bioactivity guided assay and characterized by spectral methods as...     

A High Performance Preparative Procedure for the Isolation of Degradation Products from D-Xylose

Abstract

An improved method for the preparative isolation of 3,8 dihydroxy-2-methylchromone, formed by degradation of D-xylose at 100°C is presented. From the ethyl acetate extractable part of the reaction mixture the chromone was isolated by preparative HPLC in less than one hour using a highly cross-linked dextran gel.     

Preparative Isolation of Pyrrolizidine Alkaloids Derived from Senecio Vulgaris

Abstract

A large scale method for the isolation of pyrrolizidine alkaloids has been adapted from a previously published analytical method. This method is a reverse phase high pressure liquid chromatography technique, utilizing a .005 M KH₂ PO₄ (pH 6.3) — methanol solvent system. The pyrrolizidine alkaloids derived from Senecio vulgaris (common groundsel) have been utilized in this system.     

Facile Synthesis of a Phototoxic Monofunctionalized Tetraarylporphyrin as Scaffold for Porphyrin-Quinone Conjugates

A new carboxy-monofunctionalized tertraarylporphyrin has been tested for cytotoxicity toward OV2008 human ovarian cancer cells. This compound acutely inhibits growth of ovarian cancer cells upon exposure to ambient light while suppresses long-term clonogenic survival of cells under both dark and light stimulated conditions. Because of the variable length of the linkage between the anthraquinone and porphyrin moieties, the synthesized monocarboxylated porphyrin presents a versatile scaffold for fine-tuning of the photoelectron transfer in the quinone-porphyrin conjugate. To demonstrate its synthetic value, we converted the carboxy derivative to its amino counterpart.     

Preparative HPLC for analysis of mineralocorticoids in human plasma

Summary A method has been developed to measure simultaneously in human plasma the mineralocorticoids and glucocorticoids involved in mineralocorticoid excess. Briefly: plasma extracts were chromatographied in a fully-automated procedure on a lichrospher-diol column using a hexane: isoproanol: trithylamine gradient. Eluates were collected on a preprogrammed fraction collector. Final quantification was achieved by RIA on the selected fractions. This procedure allowed: 1) the separation of each measured steroid from plasma contaminants; 2) precise collection; 3) quantification of mineralocorticoids with a precision and sensitivity equivalent to that of direct methods; and 4) improved specificity.     

高速逆流色谱法分离纯化黄芪中的芒柄花素和毛蕊异黄酮

采用高速逆流色谱法(HSCCC),以正己烷-氯仿-甲醇-水组成二相系统作为固定相与流动相,对黄芪的乙酸乙酯粗提 物进行了分离纯化。 结果发现:以正己烷-氯仿-甲醇-水(体积比为1.5∶3∶3∶2)组成的系统可以从黄芪的乙酸乙酯粗 提物中分离出毛蕊异黄酮,纯度可达95％以上,并可以初步纯化芒柄花素;接着用正己烷-氯仿-甲醇-水(体积比为4∶4∶5 ∶4)组成的系统进一步纯化芒柄花素,其纯度达95％以上。利用该方法,可以对中药黄芪中的异黄酮进行快速的分离和纯 化。     

Application of UPLC-Quadrupole-TOF-MS Coupled with Recycling Preparative HPLC in Isolation and Preparation of Coumarin Isomers with Similar Polarity from Peucedanum praeruptorum

A strategy of ultra performance liquid chromatography-quadrupole-time of flight-mass spectrometry (UPLC-Q-TOF-MS) coupled to recycling preparative HPLC was utilized to sensitively detect the minor constituents and preparatively isolate coumarin isomers from the petroleum ether extract of Peucedanum praeruptorum roots. UPLC-Q-TOF-MS was achieved on an Agilent ZORBAX Extend C-18 analytical column (50 mm × 2.1 mm i.d. 1.8 μm) using methanol:H₂O as the mobile phase, and three pairs of coumarin isomers with similar polarity were detected. Then recycling preparative HPLC was successfully used in one step for the isolation and purification of these six compounds with optimized mobile phases (methanol: H₂O, 73:27, 81:19, 78:22, v/v). The structures of six coumarins including three new coumarins named praeruptorin (F–H) (1, 3 and 6) were identified by spectroscopic analysis.     

Preparative High-Performance Liquid Chromatography Isolation of the True Proazulenes from Artemisia Arborescens L

Abstract

The use of the preparative medium-pressure liquid chromatography (prep-MPLC) and the preparative high-pressure liquid chromatography (prep-HPLC) techniques for the separation of the main true proazulenes from a purified extract of Artemisia arborescens L. are reported and discussed.     

高速逆流色谱对芦荟有效成分的制备性分离研究

1　引　　言由于高速逆流色谱具有两大突出优点 :(1 )聚四氟乙烯管中的固定相不需要载体 ,因而消除了液相色谱中由于使用载体而带来的吸附现象 ,特别适用于分离极性物质和具有生物活性的物质 ;(2 )由于其与一般色谱的分离方式不同 ,使其特别适用于制备性分离。芦荟的叶汁干燥品为一传统的常用中药。它除用作药物外 ,在化妆品行业己将芦荟系列作为我国今后的主要化妆品系列之一。另外 ,在饮料及食品等工业中 ,它得到了广泛应用。其化学有效成分主要是芦荟甙 ,以及一些少量的芦荟大黄素、异芦荟甙、β 芦荟甙等蒽醌类活性成分。2　实验部分2 .…     

高速逆流色谱法对独角莲中有效成分皂苷的分离纯化

本文采用高速逆流色谱法对独角莲中的有效成分皂苷进行分离纯化.分别以乙酸乙酯∶正丁醇∶乙腈∶水=5∶1∶1∶5(V/V)及乙酸乙酯∶正丁醇∶乙醇∶水=5∶10∶2∶20(V/V)为溶剂系统,用下相作流动相,上相作固定相,分别采用2 mL/min及1.5 mL/min 的流动相流速、800 r/min的转速对独角莲中的有效成分皂苷进行分离,得到纯度98%的胡萝卜苷6 mg.     

高速逆流色谱制备分离紫甘薯花色苷

采用高速逆流色谱法分离纯化紫甘薯花色苷.以正丁醇-乙酸乙酯-0.5%乙酸(3:1:4,V/V)为溶剂体系,上相为固定相,下相为流动相,流速2mL/min,进样量300mg,分离得到两种花色苷的混合物;混合物再以0.2%三氟乙酸-正丁醇-甲基叔丁基醚-乙腈(6:5:2:1,V/V)为溶剂体系,上相为固定相,下相为流动相,...     

Preparative Isolation of Destruxins from Metarhizium Anisopliae by High Performance Liquid Chromatography

Abstract

A method has been developed for preparative isolation of destruxins, a group of major insecticidal cyclodepsipeptides from culture broth of Metarhizium anisopliae. Prepurification of the crude extract by flash chromatography on silica gel followed by HPLC on reverse phase C18 Column using linear gradients of acetonitrile-water permitted the isolation of ten destruxins.     

芦荟色酮的高速逆流色谱分离制备方法研究

芦荟色酮是在芦荟叶中特有的一类具有抗炎和抑制酪氨酸酶等作用的活性物质。以芦荟全叶为原料,经过一系列的预处理手段,从脱色剂活性炭中获得芦荟色酮粗提物,再经过溶剂分配和富集后采用高速逆流色谱（HSCCC）对其中的色酮成分进行分离纯化。研究结果表明,采用氯仿-甲醇-水(体积比为4∶3∶2)混合溶液和二氯甲烷-甲醇-水(体积比为5∶4∶2)混合溶液作为溶剂分离系统,经过两步HSCCC可以分离纯化出色谱纯度在95％以上的芦荟色酮单体。经过紫外检测、快原子轰击质谱及核磁共振等方法的结构分析鉴定,证实分离所得物质为肉桂酰基-C-葡萄糖甙芦荟色酮。     

Preparative Reversed-Phase Liquid Chromatographic Isolation of Azadirachtin from Neem Kernels (1)

Abstract

Azadirachtin is a tetranortriterpenoid insect feeding deterrent and growth regulator present in the kernels of the neem tree, Azadirachta indica A. Juss. A procedure was developed whereby 8.7 g of >90% pure azadirachtin was obtained from 48.2 kg of neem kernels by the use of open-column reversed-phase liquid chromatography on Phase-bonded C-18 Hi-Flosil and high-performance liquid chromatography on μ Bondapak C-18 for monitoring (217 nm) the purification.     

高速逆流色谱分离制备甜瓜蒂中葫芦素类化合物

采用高速逆流色谱法分离制备了甜瓜蒂中3种葫芦素类化合物.以正己烷-乙酸乙酯-甲醇-水(1.2:0.8:0.8:1.2,V/V)为两相溶剂系统,上相为固定相,下相为流动相.在主机转速800 r/min、流动相流速2.0mL/min、分离温度25℃、检测波长254nm条件下进行分离,所得产物纯度经HPLC检测,结构经MS、...     

Preparative HPLC of the Lipid Fraction of Teucrium canadense L.

Abstract

The petrol extract of higher plants usually afford phytosterols, triterpenes, hydrocarbons and triglycerides as the major components. The separation of these by conventional column chromatography can be very time-consuming. The use of HPLC methods can effect a considerable reduction in analysis time.     

Preparative Isolation and Purification of Two Phenylpropanoids from Daphne giraldii Nitsche by HSCCC

Preparative high-speed counter-current chromatography (HSCCC) was successfully applied to purify phenylpropanoids from the stem and root bark of Daphne giraldii Nitsche, a traditional Chinese medicine. Their structures were identified on the basis of ¹H NMR and ¹³C NMR technology. The two-phase solvent system composed of n -hexane–ethyl acetate–methanol–water (2: 3: 0.5: 4, v/v/v/v) was selected for HSCCC. A total of 8.0 mg woonenoside XI (1) and 18.0 mg daphnetin (2) were obtained in one-step separation from 200 mg of the crude extract with purity of 96.0 and 99.1%, respectively, as determined by LC. And the major compound (2) showed antithrombotic activity in vitro.     

Conjugates of Cryptophycin and RGD or isoDGR Peptidomimetics for Targeted Drug Delivery

RGD-cryptophycin and isoDGR-cryptophycin conjugates were synthetized by combining peptidomimetic integrin ligands and cryptophycin, a highly potent tubulin-binding antimitotic agent across lysosomally cleavable Val-Ala or uncleavable linkers. The conjugates were able to effectively inhibit binding of biotinylated vitronectin to integrin α_vβ₃, showing a binding affinity in the same range as that of the free ligands. The antiproliferative activity of the novel conjugates was evaluated on human melanoma cells M21 and M21-L with different expression levels of integrin α_vβ₃, showing nanomolar potency of all four compounds against both cell lines. Conjugates containing uncleavable linker show reduced activity compared to the corresponding cleavable conjugates, indicating efficient intracellular drug release in the case of cryptophycin-based SMDCs. However, no significant correlation between the in vitro biological activity of the conjugates and the integrin α_vβ₃ expression level was observed, which is presumably due to a non-integrin-mediated uptake. This reveals the complexity of effective and selective α_vβ₃ integrin-mediated drug delivery.