Droplet Counter-current Chromatography Research Articles

Isolation of steroidal glycoalkaloids from Solanum incanum by two countercurrent chromatographic methods

Using a bioassay for inhibition of plant growth and a combination of two countercurrent chromatographies: rotation locular countercurrent chromatography and droplet countercurrent chromatography, two biologically active glycosidal alkaloids, solasonine and solamargine were isolated from fresh ripe fruit of Solanum incanum. The combination of these chromatographic techniques has established an efficient isolation of polar phytochemicals of steroidal glycoalkaloids.

Identification of active compounds in wheat straw extracts with allelopathic activity by HRGC‐MS and HRGC‐FTIR

AbstractThe allelopathic effects of decomposing wheat straw have been known for some time. In spite of the ecological and economical importance of the subject, only a limited number of compounds have been asociated with the allelopathic activity of wheat straw. In this study the high resolution, speed of analysis, and sensitivity of capillary gas chromatography coupled with mass spectromtry (HRGC‐MS) and Fourier transform infrared spectrometry (HRGC‐MS‐FTIR) have been used in a systematic study of the composition of biologically active wheat straw extracts. Droplet counter‐current chromatography (DCCC) was used for fractionation and isolation of components. The extract components were analyzed as methyl derivatives and free hydroxyl groups were located by means of ethylation with diazoethane. Twenty compounds were identified, most of them being phenolic acids. Naphthoic acid, azelaic acid and 1,2,3,5‐tetrabromobenzene were also identified.

Bufadienolide ausUrginea pancration1

From bulbs of URGINEA PANCRATION (Steinh.) G. de Philippe (Hyacinthaceae) 5 bufadienolides were isolated by a combination of column and droplet counter-current chromatography; their structures were elucidated mainly by FAB-MS and (1)H- and (13)C-NMR spectroscopy. Besides the already known scilliglaucoside ( 1), scillirubroside ( 2), and scilliroside ( 3), two new bufadienolides were identified: 5alpha-4,5-dihydroscillirosidin- 3beta- O-alpha- L-thevetosido-4'-beta- D-glucopyranoside and arenobufagin-3beta- O- L-rhamnopyranosido-4'-beta- D-glucopyranoside.

Physikalisch-chemische parameter einiger chloroformhaltiger fliessmittelsysteme in der droplet counter current chromatographie

Physical-chemical parameters of some chloroform-containing solvent systems in droplet counter-current chromatography Several physical-chemical parameters of ternary solvent systems (chloroform—methanol—water) used in the droplet counter-current chromatography technique are determined. These parameters are polarity, interfacial tension, viscosity, density and the composition of each phase. Their coherence and the conditions for a sufficient formation of droplets are discussed.

Volatile C13-Norisoprenoid Compounds in Riesling Wine Are Generated From Multiple Precursors

The precursors of vitispirane (two diastereoisomers), 1,1,6-trimethyl-l,2-dihydronaphthalene (TDN), damascenone, and a fourth unknown volatile norisoprenoid in Riesling wine were analyzed by droplet counter-current chromatography (DCCC). The volatile compounds were monitored by GC-MS after mild acid hydrolysis of pooled DCCC fractions. Each of the four volatiles was derived from several precursors. The precursors appear to include glycoconjugates involving different conjugating moieties and also non-glycosidic compounds. The vitispiranes and damascenone are each produced from at least two aglycons which, in turn, are variously glycosylated. Consequences are discussed for the existence in grapes and wines of multiple precursors of the volatile flavor compounds, and a rapid method for assessing bottle aging potential of wines is suggested

Liquid-liquid partition chromatography in natural product isolation

The applications of droplet countercurrent chromatography and centrifugal partition chromatography (CPC) to the isolation and purification of natural products are described. The former is a well established technique which has been used extensively in the isolation of polar substances and the fractionation of crude plant extracts. The recent introduction of different CPC techniques and instruments has permitted a reduction of separation times. Two of these instruments (the cartridge centrifugal partition chromatograph and the high-speed coil separator-extractor) have been applied to the separation of natural products of widely differing polarities. They offer the advantage of being able to reverse the solvent flow. Other developments are in progress to further improve the capabilities of these chromatographs. A description of the different instruments is provided, together with details of their mode of operation and a discussion of experimental parameters, such as flow-rates, rotation speeds, solvent selection and the application of aqueous and non-aqueous systems.

Flavonoids from Orthosiphon spicatus.

In our studies on Orthosiphon spicatus, the ethyl acetate extract of the plant was separated by droplet countercurrent chromatography or by flash chromatography. Further separation was achieved by centrifugally accelerated TLC on a Chromatotron, followed by preparative TLC and/or recrystallization

Plant antiviral agents, VI. Isolation of antiviral phenolic glucosides from Populus cultivar Beaupre by droplet counter-current chromatography.

Bioassay-guided isolation of the 80% EtOH extract of the leaves of Populus cultivar Beaupré by means of dccc afforded four known phenolic glucosides. Salicin and salireposide were shown to be, at least partially, responsible for the antiviral activity of the extract against poliomyelitis and Semliki forest viruses.

Droplet counter current chromatography of the carotenoids of parsleyPetroselinum crispum

The application of droplet counter current chromatography to the separation of the carotenoids of parsley, β-carotene, lutein, violaxanthin and neoxanthin, is described. The solvent system consists of petroleum spirit bp 40–60°C: acetonitrile: methanol in the proportions 50∶10∶40. The upper layer is used as the mobile phase and the lower layer as the stationary phase.

Separation of non-polar compounds by droplet counter-current chromatography

Separation of non-polar compounds by droplet counter-current chromatography

Phenolic constituents of licorice. II. Structures of licopyranocoumarin, licoarylcoumarin and glisoflavone, and inhibitory effects of licorice phenolics on xanthine oxidase.

An anti-HIV (human immunodeficiency virus) phenolic constituent, licopyranocoumarin (4), and two other new phenolics named licoarylcoumarin (5) and glisoflavone (6) were isolated from Si-pei licorice (a commercial licorice; root and stolon of Glycyrrhiza sp. from the north-western region of China) using droplet countercurrent chromatography and centrifugal partition chromatography, and their structures were assigned based on chemical and spectroscopic data. Kaempferol 3-O-methyl ether (7) and licocoumarone (8) were also isolated from the licorice. The inhibitory effects of ten licorice phenolics on xanthine oxidase were examined. Licochalcone B (1), glycyrrhisoflavone (2), 8 and licochalcone A (19) showed 50% inhibition at the concentration of 1.3-5.6 x 10(-5) M.

Separation of non-polar compounds by droplet counter-current chromatography

Separation of non-polar compounds by droplet counter-current chromatography

Isolation of biologically active plant constituents by liquid chromatography

Strategies are outlined for the separation of biologically active products of plant origin. The techniques involved include low-pressure liquid chromatography, semi-preparative high-performance liquid chromatography, flash chromatography and droplet counter-current chromatography. Their application to the isolation of compounds from Sesamum angolense (Pedaliaceae), Psorospermum febrifugum (Guttiferae) and Cordia goetzei (Boraginaceae) is described.

Macrocyclic pyrrolizidine alkaloids from Senecio anonymus. Separation of a complex alkaloid extract using droplet counter-current chromatography.

Ten 12-membered macrocyclic pyrrolizidine alkaloids, all of them esters of the necines, retronecine or otonecine, have been isolated from Senecio anonymus. The separation, carried out by droplet counter-current chromatography, afforded senecionine [1], integerrimine [2], retrorsine [3], senkirkine [5], neosenkirkine [6], otosenine [10], hydroxysenkirkine [7], and a new alkaloid given the trivial name anonamine [9]. Traces of usaramine [4] and another new alkaloid, hydroxyneosenkirkine [8], were detected by 1H nmr. In addition, the previously unreported 3a beta-hydroxy-4-ethoxy-2,6-perhydroindoledione [11] was isolated. X-ray structures were obtained for neosenkirkine [6], hydroxysenkirkine [7], anonamine [9], and [11]. 1H-13C heteronuclear shift correlated nmr (HETCOR) provided unambiguous chemical shift assignments for 13C-nmr data. Antitumor activity was assayed using the A204-rhabdomyosarcoma cell line in soft agarose.

Thin-layer chromatography of ecdysteroids originated fromSilene otites L. (Wib.)

Thin-layer chromatographic investigations of ecdysteroids have been carried out to monitor their isolation by column chromatography and droplet countercurrent chromatography as well as to control the homogeneity of the pure products. Isolation scheme and chemical structure of the 20-hydroxyecdysone-22-benzoate and that of three new ecdysteroid compounds, 2-deoxy-1,20-dihydroxyecdysone, 2-deoxyecdysone-22-acetate and 2-deoxy-20-hydroxyecdysone-22-acetate are also presented.

Isolation of parthenolide by droplet counter-current chromatography

The advantages and potential of droplet counter-current chromatography in the semi-preparative- and preparative-scale isolation of parthenolide and related sesquiterpene lactones was studied. Two systems, benzene—chloroform—methanol—water and chloroform—trichloroethylene—acetonitrile—methanol—water, were found to be suitable for the isolation of sesquiterpene lactones from Asteraceae plants.

Droplet Countercurrent Chromatography: Recent Applications in Natural Products Chemistry

Abstract A few recent examples of our own modifications, procedures, and experiences utilizing DCCC are discussed that have enabled us to use DCCC more efficiently

Isolation of virginiamycin-M 1 by droplet counter-current chromatography

Isolation of virginiamycin-M 1 by droplet counter-current chromatography

Application of droplet counter-current chromatography to the isolation of vitamin B 12

Application of droplet counter-current chromatography to the isolation of vitamin B 12

Application of droplet countercurrent chromatography to the analysis of conjugated forms of terpenoids, phenols, and other constituents of grape juice

Minor polar constituents isolated from juices of the Vitis vinifera, cv. Rhine Riesling, Muscat of Alexandria, and Chardonnay, were separated by droplet countercurrent chromatography (DCCC). Analyses were made of compounds in the DCCC fractions by GC-MS after enzymic hydrolysis and by NMR after acetylation and further liquid chromatography. These procedures have allowed identification of conjugated forms, including glycosides, of monoterpenoids, C13norisoprenoids, phenols, and other compounds. Among the grape constituents identified were (E)-6-hydroxy-2,6-dimethylocta-2,7-dien-l-yl-β-D-gluco-pyranoside and the corresponding 6-O-α-arabinofuranosyl-β-D-glucopyranoside, l-methyl-l-(trans-5′;-methyl-cis-5′-vinyltetrahydrofuran-r-2′-yl)ethyl-6-O-α-arabinofuranosyl-β-D-glucopyranoside, astilbin, quercetin-3-O-β-glucopyranuronoside and roseoside. Additionally, conjugates of (E)-2,6-dimethyl-octa-3,7-diene-2,6-diol, (E)-2,6-dimethyloct-7-ene-2,6-diol, (E)-9-hydroxymegastigma-4,7-dien-3-one, (E)-3-hydroxymegastigma-5,8-dien-7-one, zingerone, 4-(4-hydroxy-3-methoxyphenyl)butan-2-ol, and 3-(4-hydroxy-3-methoxyphenyl) propan-l-ol, 2-(4-hydroxy-3-methoxyphenyl)ethanol, methyl vanillate, cinnamyl alcohol, and 3-phenylpropan-l-ol were found. The work demonstrates that DCCC will facilitate separation and analysis of polar, nonvolatile constituents of grapes, including precursors of volatile flavorants. © 1987, American Chemical Society. All rights reserved.