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.     

Rapid Sara Seprations by High Performance Liqid Chromatography

Abstract

This paper presents both rapid analytical and preparative high performance liquid chromatographic (HPLC) techniques for separating liquid-fuel type materials into saturates, aromatics, resins, and asphaltenes (SARA). The preparative method, an adaptation of a technique developed by Jewell, et. al. (1, 4), significantly decreases analysis time. The analytical technique utilizes HPLC to achieve the same separations in less time.     

A Simple Liquid Chromatographic Method for Analysis and Isolation of the Unsaturated Components of Anacardic Acid

Abstract

Good analytical and preparative separation of the saturated, monoene, diene and triene components of anacardic acid have been achieved by reverse phase HPLC on a C₁₈ column by isocratic elution with methanol-aqueous acetic acid.     

A review of: “HPLC of Biological Compounds-A Laboratory Guide,by William S. Hancock & James T. Sparrow, (Volume 26 of the Chromatographic Science Series,Jack Cazes,Editor), Marcel Dekker,Inc., New York,NY, 1984, 361 pp., £39.75 (US)”.

Abstract

The analytical and preparative separation of the saturated, monoene, diene and triene constituents of cardanol and cardol have been achieved by reverse phase HPLC on a C₁₈ column using gradient elution.     

Mass spectrometry-guided isolation of two new benzoquinoline alkaloids from Macleaya cordata

Two new alkaloids, named 2,3-methylenedioxy-7,10-dimethyl-7,8,9,10-tetrahydro-benzoquinoline (1) and 2,3-methylenedioxy-7,10-dimethyl-8-carboxyl-benzoquinoline (2), were detected primarily from the fruits of Macleaya cordata by their different fragmentation pathways. And then isolation of the two compounds was performed by column chromatography and preparative HPLC under the guiding of mass spectrometry. Finally, their structures were determined by spectroscopic analysis.     

A MULTIGRAM PREPARATIVE SYNTHESIS OF CHOLEST-4-EN-3α,6β- AND -3α,6α-DIOLS

A preparative synthesis of cholest-4-en-3α,6β- and -3α,6α-diols 10 and 15 using cheap reagents and simple working-up procedures without chromatography on a multigram scale is described.     

Amidoalkylation of Tervalent Phosphorus Chlorides with N-α-Hydroxypolyhalogenoalkyl Amides

Abstract

A new preparative method for synthetically and biologically important N-acyl-, N-phosphoryl-, and N-sulfonylaminopolyhalogenoalkylphosphonyl derivatives 2 is presented.     

Simple preparative synthesis of spinochrome e,a pigment from sea urchins of the genus <Emphasis Type="Italic">Echinothrix</Emphasis>

A preparative synthesis of spinochrome E (2,3,5,6,7,8-hexahydroxy-1,4-naphthoquinone, 1), a metabolite of sea urchins of the genus Echinothrix, is proposed starting from 2,3-dichloro-6,7-diethoxynaphthazarine (4) with simultaneous substitution of the Cl atoms by hydroxyl- and nitro-groups, reduction of the latter, and subsequent removal of alkoxy groups and hydrolysis of the amine in the resulting 3-amino-2-hydroxy-6,7-diethoxynaphthazarine (6).     

Hydrocarbon Type Separation of Lubricating Base Oil in Multigram Quantity by Preparative HPLC

Abstract

A preparative High Pressure Liquid Chromatography (HPLC) method has been developed to separate lubricating base oil into its three major hydrocarbon fractions: saturates, aromatics, and polars. The results are directly comparable to ASTM Method D2007, hydrocarbon type analysis by gradient elution liquid chromatography. The new method employs a preparative HPLC unit with dual, radially compressed columns consisting of clay and alumina/silica gel columns. Multigram quantities of minor components (1 to 2% by wt.) of a base oil can be isolated for further study.     

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.     

Sex Pheromone of Chilo Suppressalis: Efficient Syntheses of (Z)-11-Hexadecenal, (Z)-13-Octadecenal And (Z)-9-Hexadecenal

The constituents of the sex attractant pheromone of Chilo suppressalis: (Z)-11-Hexedecenal 1, (Z)-13-octadecenenal 2 and (Z)-9-Hexadecenal 3 have been synthesized as their ethylene acetals 19, 15 and 13, in six steps from easily available compounds. The synthetic methodology can be applied to preparative scale.     

Preparative HPLC Separation of Epimeric Guaianolides

Abstract

A technique for the preparative HPLC separation of the C-4 epimeric unstable guaianolides matricin and 4-epimatricin, proazulenes isolated from Artemisia arborescens L., is reported.     

An improved synthesis of latanoprost involving effective control on 15(S) diastereomer

Abstract

An improved process for the synthesis of latanoprost having excellent optical purity (de 99.9%, [α]_D²⁰?=?+35.37° (c?=?0.90, acetonitrile)) without use of preparative HPLC is described. This process involves effective purification of hydroxyl intermediate (5A) through solvent crystallization followed by inhibition of inversion of the chiral center at C-15 position. This was possible due to judicious use of diol intermediate (6) for double bond reduction prior to hydroxyl protection.     

High-Performance Hydrophobic Interaction Chromatography of Proteins on TSKgel Phenyl-5PW Preparative Column

Abstract

TSKgel Phenyl-5PW preparative column of 200 × 55 mm I.D. was evaluated with respect to resolution, sample loading capacity and applications to the purification of enzymes. The preparative column provided similar separations as analytical column (75 × 7.5 mm I.D.) and 150 × 21.5 mm I.D. preparative column. The sample loading capacity was 200 – 1000 mg depending on the sample. If the slight decrease in resolution is acceptable, much more samples could be applied. Lipoxidase, phosphoglucose isomerase and lactate dehydrogenase could be purified to a great extent with high recovery of activity (more than 80%).     

OXIDATION OF THE ALKYL-, ARYL-, AND AMINO-SULFONIUM IONS TO THE SULFOXONIUM IONS AND ITS REACTION MECHANISM

Abstract

Hitherto, the preparative method of the sulfoxonium ions has been practically limited to thealkylation of the sulfoxides with methyliodide. The yields of the desired sulfoxonium salts by this method are usually poor except that of trimethylsulfoxonium iodide, Diarylalkyl- or triaryl-sulfoxonium ions can not be prepared by this alkylation.     

Countercurrent Chromatography for Isolation of Flavonol Glycosides From Ginkgo Biloba Leaves

Abstract

A procedure which combined countercurrent chromatography with gradient elution and preparative high-performance liquid chromatography was developed for the isolation and the purification of the seven predominant flavonol glycosides from Ginkgo biloba leaves.     

Routine Preparative HPLC of Aromatic Silyl Compounds on Caffeine Coated on Silica Gel

Abstract

A liquid chromatographic method using caffeine coated on silica gel, for separation and purification of acenaphthenylsilyl compounds is described. This has been achieved on a preparative scale.     

Electroreduction of a Sodium Salt of 4-Nitrosodiphenylamine: Effect of the Technological Solution Components

Two methods of preparation of 4-aminodiphenylamine (I) are compared: by electrochemical reduction of an alkaline solution of 4-nitrosodiphenylamine (II), extracted from a technological solution, and by electrolysis of the solution itself, which contains, apart from the nitroso compound, methanol and NaCl. By voltammetry and preparative electrosynthesis it is shown that the lower reduction rate of the technological solution of the Na salt of II is due to inhibiting effects of methanol and NaCl. Tetraalkylammonium cations, decreasing the limiting reduction current of II, do not affect the electrosynthesis rate when the generated I is continuously extracted into a water-immiscible solvent.     

A Low Cost Gram Quantity Preparative Reverse Phase Chromatography System

Abstract

The preparation of a low cost reverse phase preparative liquid chromatography system is described. The described system is capable of providing gram quantity scale-up from analytical reverse phase hplc systems. Load capacity is in the two gram range.     

The Use of Polystyrene Gels in Preparative Recycle-HPLC for the Separation of Structurally Related Molecules

Abstract

This paper deals with the use of polystyrene gels in high performance liquid chromatography for preparative separations of small molecules with very similar structures. The preparative chromatograph, equipped with a recycle device and made in our laboratory, is described. The column set, consisted of three columns packed with low porosity polystyrene gel. The mobile phase was diisopropylether. Three particle sizes (10μ, 20μ, 50μ) were studied for improving the preparative performance. We checked the very high efficiency of our recycling system versus sample load. High sample loadings (up to 100 grams) can be injected when the separation does not require a large number of plates but typical sample loads are 10–20 grams for high performance separations. Some examples of separation of diastereoisomers, configurational isomers or related structure molecules are given. The advantages of our preparative system are discussed.