bluuebunny/crossref_metadata_2025_split huggingface dataset:
The applications of hydrophobic interaction chromatography to the purification of plant proteins
Authors: Pennings E. J. M. , Meijer A. H. , Stevens L. H. , Verpoorte R. 
Published: March 2007

AbstractProtein separation by hydrophobic interaction chromatography (HIC) depends on the differences in surface hydrophobicity of the constituent proteins and is hence complementary to chromatographic techniques based on the charge or the size of the macromolecule. This review summarises some of the recent developments in HIC supports and discusses the parameters that must be considered in designing an efficient chromatographic system. The application of HIC to the purification of enzymes of secondary compound biosynthesis that cannot be obtained in pure form by size‐exclusion and ion‐exchange techniques alone is exemplified by reference to recent studies on tryptophan decarboxylase, strictosidine synthase and geraniol‐10‐hydroxylase.
A bioautographic agar overlay method for the detection of antifungal compounds from higher plants
Authors: Rahalison L. , Hamburger M. , Hostettmann K. , Monod M. , Frenk E. 
Published: March 2007

AbstractA simple bioautographic agar overlay assay using Candida albicans as the indicator organism for the detection and activity‐guided fractionation of antifungal compounds by thin layer chromatography has been developed. Inhibition of fungal growth was assessed by the detection of dehydrogenase activity with thiazolyl blue (methylthiazolyltetrazolium chloride; MTT). A series of clinically used antimycotic agents were tested in order to determine the sensitivity of the assay. The compatibility of the agar overlay technique with chemically modified silica gel (Diol and RP‐18) plates and with various organic solvents was evaluated. The methodology is also applicable to the search for antibacterial compounds, as shown with Bacillus subtilis as a test organism.
Separation of C25 epimers of steroidal sapogenins by reversed phase high performance liquid chromatography at low temperature
Authors: Wu Yue , Wu Peng 
Published: March 2007

AbstractThree pairs of C25 epimers of steroidal sapogenins–‐diosgenin (1) and yamogenin (2), hecogenin (3) and sisalagenin (4), tigogenin (5) and neotigogenin (6)–‐were separated by reversed phase high performance liquid chromatography. It is shown that the resolution of separation of the epimers increases with a decrease in column temperature and that optimal resolution is attained within the temperature range 0–10 °C.
Purification and characterization of calmodulin from cultured cells of catharanthus roseus
Authors: Radvanyi Laszlo G. , Dicosmo Frank 
Published: March 2007

AbstractThe Ca2+‐binding protein calmodulin has been purified to homogeneity from cell suspension cultures of Catharanthus roseus by high performance liquid chromatography and two isoforms have been detected by SDS‐PAGE and non‐denaturing PAGE. The methodologies employed in the isolation, purification, assay and physicochemical characterization of the protein are discussed, and the differences between C. roseus calmodulin and spinach calmodulin are described.
Analytical procedures for cyclic nucleotides and their associated enzymes in plant tissues
Authors: Brown E. G. , Newton R. P. 
Published: March 2007

AbstractA substantial body of published information has accrued indicating the presence in higher plants of all the components needed for functional cyclic nucleotide‐regulated control systems. In order to consolidate this and to stimulate further research, the methodology currently available for the analysis of cyclic nucleotides in plants and for assaying their associated enzymes is critically reviewed. The extraction of cyclic nucleotides, their separation by high performance liquid chromatography and identification using the latest techniques in mass spectrometry is described, and the determination of these compounds by radioimmunoassay and by saturation binding assay is examined. Assays for the cyclase, cyclic nucleotide phosphodiesterases and protein kinases are critically appraised. Other cyclic nucleotide‐binding proteins are considered. The validity and accuracy of the various methods in connection with plant analysis are evaluated.
A simple assay for adenosine 3′,5′‐cyclic monophosphate (cyclic AMP) and its application to the study of cyclic AMP production in the lichen Himantormia lugubris
Authors: Vicente Carlos , Mateos Jose L. 
Published: March 2007

AbstractThis paper describes an accurate, specific and sensitive high performance liquid chromatographic method for the identification and quantification of adenosine 3′,5′‐cyclic monophosphate (cyclic AMP). Recovery of the cyclic nucleotide has been estimated to be about 82.6% after the extraction procedure. By using this method, the cyclic nucleotide has been identified in the lichen Himantormia lugubris. Production of cyclic AMP is achieved in the dark by this lichen species and is inhibited by white light. This inhibition is reversed by adding 3‐(3'‐dichlorophenyl)‐1,1‐dimethylurea or adenosine triphosphate to the incubation medium. The effects of red light and far‐red light on cyclic AMP accumulation by the lichen have been investigated.
The use of combined capillary liquid chromatography/mass spectrometry for the identification of a gibberellin glucosyl conjugate
Authors: Moritz Thomas 
Published: March 2007

AbstractGibberellin A9 (GA9) glucosyl ester was identified in shoots of Sitka spruce [Picea sitchensis (Bong.) Carr.] grafts using capillary reversed phase high performance liquid chromatography combined on‐line with a double focusing mass spectrometer. The column effluent was introduced into the ion source of the mass spectrometer via a frit‐fast atom bombardment liquid chromatography/mass spectrometry interface. Negative ion mass spectra were obtained and compared with the spectrum of an authentic standard. In order to confirm the identity of the aglycone, a daughter ion spectrum from the parent ion m/z 315 was obtained by B/E linked scanning and compared with a daughter ion spectrum of free GA9. Furthermore, the elemental composition of the GA conjugate was determined by high resolution mass spectrometry.
Nitrogen‐phosphorus detector potential in tropane alkaloid gas chromatography
Authors: Martinsen A. , Hiltunen K. , Huhtikangas A. 
Published: March 2007

AbstractA gas chromatographic (GC) nitrogen‐phosphorus detector (NPD) is compared with a flame ionization detector (FID) for the quantitation of some important tropane alkaloids present in plant material. Though slightly cumbersome in routine work, NPD has a distinct sensitivity advantage over FID for these alkaloids. An injector of the programmed temperature vaporizer (PTV) type permitted extension of the range of solvents which may be employed for the preparation of alkaloid samples for GC assays in which detection is to be accomplished by NPD.
Analysis of carotenoids by high performance liquid chromatography and diode‐array detection
Authors: Bramley Peter M. 
Published: March 2007

AbstractThe use of diode‐array detectors with high performance liquid chromatography enables the separation and analysis of carotenoids from biological samples to be achieved in a significantly shorter period than when conventional ultraviolet/visible detectors are used. This relates to the ability of diode‐array detectors to provide full spectral analysis of the compounds during chromatography. The features of diode‐array detectors, including their advantages and drawbacks, are discussed, particularly with respect to the identification and quantitation of carotenoids.
Quantification of polyamine losses during manipulation and assay procedures
Authors: Dinnella C. , Crues J. A. , D'Orazi D. , Encuentra A. , Gavalda E. G. , Serafini‐Fracassini D. 
Published: March 2007

AbstractLosses in polyamine recovery during manipulation and assay procedures have been detected. They are partly due to the binding of polyamines at low concentration (around 5 μM for putrescine and 100 μM for spermine) to the containers and depend on the chemical nature of the latter, on the pH of the solution and on the length of time for which they remain in contact with the container. The recovery of labelled polyamines after dansylation was about 45% of the initial radioactivity. Remarkably high losses occurred when bound polyamines, obtained by in vitro incubation with cell‐free extracts, were estimated after acidic hydrolysis. Standard free polyamines, subjected to acidic hydrolysis conditions, yielded a 50–60% recovery, both measured as radioactivity and fluorescence, compared to standard polyamines not subjected to hydrolysis. If carbohydrates are present, the recovery after hydrolysis can be even lower, depending on the sequence in which the reagents of the dansylation procedure are added. Ion exchange chromatography to remove carbohydrates improved this recovery.
Separation, identification and quantification of monomers from cutin polymers by high performance liquid chromatography and evaporative light scattering detection
Authors: Gérard Hervé C. , Osman Stanley F. , Fett William F. , Moreau Robert A. 
Published: March 2007

AbstractA silicic acid high performance liquid chromatographic method which utilizes an evaporative light scattering detector has been developed for the separation of cutin monomers. This binary gradient system was successfully applied to separate underivatized monomers of several fruit cutins including those from apple cvs. Golden Delicious and Red Delicious (Malus pumila), tomato (Lycopersicon esculentum), grapefruit (Citrus paradisi) green pepper (Capsidum annum) and pumpkin (Cucurbita pepo). All cutin monomers, from the least polar, monohydroxy saturated and unsaturated fatty acids, to the most polar, trihydroxy saturated and unsaturated fatty acids, were separated. Monomer identity was confirmed by gas chromatography‐mass spectromety of collected peaks. The gradient was also able to separate positional isomers of dihydroxy fatty acids, a separation not yet achieved by gas chromatography. The relationship between detector response and the mass of five common cutin monomers was obtained.
Separation and identification of some naturally occurring chalcones by reversed phase high performance liquid chromatography
Authors: Koupai‐Abyazani Mohammed R. , Bohm Bruce A. 
Published: March 2007

AbstractA reversed phase high performance liquid chromatographic method for the separation and identification of some chalcones is reported. The system consists of a Lichrospher 100 RP‐18 Merck column and a combination of isocratic and linear gradient elution with water:acetic acid (99:1) and methanol as solvents. Well‐resolved and symmetrical peaks were obtained for a wide range of these compounds with a variety of substitution patterns. The effect of the number, position, type of substituents and the size of the molecules on the chromatographic behaviour of chalcones have been discussed. Some unpublished ultraviolet data of chalcones are also reported.
A comparative study of different amberlite XAD resins in flavonoid analysis
Authors: Tomás‐Barberán Francisco A. , Blázquez M. Amparo , Garcia‐Viguera Cristina , Ferreres Federico , Tomás‐Lorente Francisco 
Published: March 2007

AbstractA comparative study of the recovery of flavonoids (both aglycones and glycosides) by different Amberlite XAD resins has been achieved. No significant differences in the percentages of recovery were found with the chemical nature and physical characteristics of the different resins. A flavonoid recovery higher than 90% is possible in a number of cases. The possibility of fractionating the adsorbed flavonoids by desorption with methanol: water mixtures has also been studied. The polystyrene resins (XAD‐2, XAD‐4 and XAD‐16) were found to be more useful for fractionation purposes than the polyacrylic resins (XAD‐7, XAD‐8). The results suggest that Amberlite XAD‐2 is the most suitable for the recovery and fractionation of flavonoids from plant extracts and foods rich in sugars and other polar compounds such as honey and fruit jams.
Development of an enzyme immunoassay for the determination of tobacco alkaloids in plant material
Authors: Fliniaux Marc‐André , Manceau Françoise , Jacquin‐Dubreuil Annie 
Published: March 2007

AbstractA competitive enzyme immunoassay (EIA), using anti‐nornicotine antibodies is described. The specificity of these antibodies was checked by a high pressure liquid chromotographic (HPLC) procedure. Following purification, the alkaloid extracts were simultaneously analysed by EIA and HPLC and similar results were obtained. The high sensitivity of EIA and its good specificity toward the major tobacco alkaloids enabled us to perform analysis on crude extracts prepared from very small samples (ca. 1 mg dry weight) of plant material. The method can therefore be applied to the localization of alkaloids in Nicotiana plants and cell suspensions.
High performance liquid chromatographic analysis of chromone alkaloids from Schumanniophyton species
Authors: Houghton Peter J. , Woldemariam Tibebe Z. 
Published: March 2007

AbstractAn optimized high performance liquid chromatographic (HPLC) procedure for the analysis and quantitation of piperidino‐chromone alkaloids has been developed, featuring short retention times, high and adequate resolution. The HPLC system uses a C‐18 reversed phase column eluted with methanol:20 mM potassium dihydrogen phosphate (50:50) with UV detection at λ=254 nm. Comparative studies on the content of chromone alkaloids in the root, stem‐ and root‐bark of Schumanniophyton magnificum and S. problematicum were carried out using this method.
Carbon‐13 nuclear magnetic resonance spectra of some tetracyclic diterpenoids isolated from Elaeoselinum species
Authors: Grande Manuel , Morán Joaquín R. , Macías María Jesús , Mancheño Balbino 
Published: March 2007

AbstractThe 13C nuclear magnetic resonance (NMR) spectral data for nine ent‐kaurenes, 12 ent‐beyeranes and four ent‐atisene derivatives, isolated from Elaeoselinum species, are discussed. The assignments of the 13C signals were based on DEPT sequences, two‐dimensional (2D) δH/δC NMR spectra and comparison with known compounds. The assignments of some known ent‐kaurenes are revised.
Ion‐pair and ion‐suppression high performance liquid chromatographic analysis of alkaloidal constituents of Artabotrys monteiroae
Authors: Kato Atsushi , Moriyasu Masataka , Nishiyama Yumi , Ichimaru Momoyo , Juma Francis D. , Ogeto John O. 
Published: March 2007

AbstractIon‐pair and ion‐suppression mode high performance liquid chromatography was conducted on the alkaloidal constituents of the roots of Artabotrys monteiroae, an important medicinal plant in Kenya having analgesic and anti‐inflammatory action. Use of sodium perchlorate as an ion‐pair reagent led to excellent separation. In the ion‐suppression system containing ammonium acetate, the separation was rather poor, but liquid chromatography‐mass spectrometry was possible, which was not the case in the ion‐pair system. Four aporphines, (‐)‐asimilobine, (+)‐wilsonirine, (+)‐norisoboldine and anonaine, and a benzylisoquinoline, (+)‐reticuline, were identified after isolation by preparative thin layer chromatography.
The structure of velutinol A, an anti‐inflammatory compound with a novel pregnane skeleton
Authors: Yunes Rosendo A. , Pizzolatti Moacir G. , Sant'Ana Antonio E. G. , Hawkes G. E. , Calixto Joao B. 
Published: March 2007

AbstractThe isolation and purification of velutinol A, a potent anti‐inflammatory agent from Mandevilla velutina is reported together with spectroscopic evidence which shows that the structure comprises a novel pregnane skeleton.
Studies of alkaloids in foliage of Erythrina berteroana and E. poeppigiana: Detection of β‐erythroidine in goats milk
Authors: Soto‐Hernandez M. , Jackson A. H. 
Published: March 2007

AbstractThe alkaloids present in the leaves of Erythrina berteroana and E. poeppigiana have been screened by gas chromatography and mass spectrometry. Samples of milk from goats which had been fed with leaves of these plants have also been analysed. Traces of β‐erythroidine were detected in the milk and this raised the question of whether it was suitable for human consumption.
A rapid high performance liquid chromatographic method for the separation of the alkaloid precursor L‐tyrosine and six tetrahydroisoquinoline alkaloids of Papaver somniferum
Authors: Kraml Marlene M. , Dicosmo Frank 
Published: March 2007

AbstractA high performance liquid chromatographic (HPLC) method was developed for the qualitative and quantitative determination of L‐tyrosine and six common tetrahydroisoquinoline alkaloids (papaverine, noscapine, sanguinarine, morphine, codeine and thebaine) of Papaver somniferum. The reversed phase HPLC method yields baseline separation of the alkaloids in 20 min and is achieved using a simple H2O: MeOH linear gradient. Silanol effects commonly associated with the separation of such strongly basic compounds were minimized by the addition of the amine modifier, triethylamine, to the mobile phase.
The determination of triptolide from Tripterygium hypoglaucum and T. wilfordii by high resolution gas chromatography
Authors: Liang Zhang , Zheng‐Xing Zhang , Long‐Sheng Sheng , Deng‐Kui An 
Published: March 2007

AbstractA method has been developed to determine the content of the bioactive diterpenoid triptolide in specimens of Tripterygium hypoglaucum and T. wilfordii obtained from 21 different districts of China. Triptolide was extracted from powdered plant material with chloroform and, following removal of alkaloids, esterified with CH2N2 and silylated with N‐(trimethylsilyl)imidazole. Samples were analysed quantitatively by high resolution gas chromatography with n‐hexatriacontane as internal standard. The minimum level of detection of triptolide was 25 ng and mean recoveries of 96% (relative standard deviation 8.7%) were recorded for extracts containing 25–75 μg/mL of the diterpenoid.
Thin layer chromatography of bilobalide and ginkgolides A, B, C and J on sodium acetate impregnated silica gel
Authors: van Beek Teris A. , Lelyveld Gerrit P. 
Published: March 2007

AbstractA normal phase thin layer chromatographic procedure for the separation and detection of bilobalide and ginkgolides A, B, C and J has been developed. The method is based on the impregnation of commercially available silica gel F254 plates with sodium acetate. Silica gel thus impregnated gives a good separation of all major terpene trilactones in ginkgo leaves (0.06 ⩽ ΔRf 0.17) with the solvent systems ethyl acetate: hexane (9:1) (non‐saturated chamber) or 100% methyl acetate (saturated chamber). The sodium acetate has two functions: it greatly improves the separation of the ginkgolide pairs G‐A/G‐B and G‐J/G‐C, and it enhances the sensitivity of the acetic anhydride spray reagent. Quantities of less than 1 μg of all four ginkgolides and bilobalide can be detected.
Identification of the reaction products of rosmarinic acid synthase from cell cultures of Coleus blumei by ion spray mass spectrometry and tandem mass spectrometry
Authors: Petersen Maike , Metzger Jörg W. 
Published: March 2007

AbstractDifferent substrates were used in reaction assays for rosmarinic acid synthase, an enzyme involved in rosmarinic acid biosynthesis in cell cultures of Coleus blumei. In order to introduce the cinnamoyl moiety of the ester, 4‐coumaroyl‐CoA and caffeoyl‐CoA were applied as substrates; for the hydroxyphenyllactic acid moiety, 4‐hydroxyphenyllactate and 3,4‐dihydroxyphenyllactate were used. Four different reaction products were thus produced and these were analysed by ion spray mass spectrometry and tandem mass spectrometry after purification by semi‐preparative high pressure liquid chromatography. The molecular masses and the fragmentation patterns obtained by tandem mass spectrometry of the reaction products formed by the catalysis of rosmarinic acid synthase were in agreement with the structures of rosmarinic acid (caffeoyl‐3′,4′‐dihydroxyphenyllactate) and rosmarinic acid‐like esters (4‐coumaroyl‐4′‐hydroxyphenyllactate, 4‐coumaroyl‐3′,4′‐dihydroxyphenyllactate, caffeoyl‐4′‐hydroxyphenyllactate) as expected for the substrates used in the enzyme reaction.
Synthesis and mass spectral analysis of coenzyme a thioesters of anthranilic acid and its N‐methyl derivative involved in acridone alkaloid biosynthesis
Authors: Baumert Alfred , Schmidt Jürgen , Gröger Detlef 
Published: March 2007

AbstractCoenzyme A thioesters of anthranilic acid and N‐methylanthranilic acid were synthesized. The corresponding N‐hydroxysuccinimidyl esters proved to be useful as activated intermediates to prepare anthraniloyl‐CoA and N‐methylanthraniloyl‐CoA. These compounds were characterized by positive and negative ion liquid secondary ion mass spectrometry. Acridone synthase from suspension cultures of Ruta graveolens catalyses the condensation of N‐methylanthraniloyl‐CoA and malonyl‐CoA. The reaction product 1,3‐dihydroxy‐N‐methylacridone was directly identified after the extraction of the assay mixture by electron impact mass spectrometry and capillary gas chromatography.
Analysis of constituents of Iris rhizomes. Part I: High performance liquid chromatographic‐particle beam‐mass spectral analysis of iridals from Iris pallida rhizomes
Authors: Bicchi Carlo , Rubiolo Patrizia 
Published: March 2007

AbstractIridals are a class of triterpenoids characteristic of the Iris genera: they have been demonstrated to be the precursors of irones, a group of terpenoids very well known for their smell of violets. This paper reports the results of the analysis of Iris pallida extracts carried out by high performance liquid chromatography coupled through a particle beam interface to a mass spectrometer in different ionization modes. Fourteen iridals and fatty acid iridal esters were characterized in the Iris pallida rhizome extracts under investigation. The direct identification of iridal myristates is reported here for the first time.
Isolation, characterization and analysis of polyhydroxy alkaloids
Authors: Molyneux Russell J. 
Published: March 2007

AbstractThe recent recognition of polyhydroxy alkaloid glycosidase inhibitors as a unique class of alkaloids has generated considerable interest in the isolation of additional members, in addition to the analysis and detection of those currently known. The different properties of this group from those of conventional alkaloid classes requires novel approaches to such problems. The methods most suitable for extraction, isolation, structural elucidation, detection and analysis are critically reviewed. Application of such methods should lead to further expansion of this class of compound, providing significant information regarding structure‐activity relationships.
Quantitative cytochemical localization of cinnamyl alcohol dehydrogenase activity in plant tissues
Authors: Baudracco S. , Grima‐Pettanati J. , Boudet A. M. , Gahan P. B. 
Published: March 2007

AbstractAlthough cinnamyl alcohol dehydrogenase is an important enzyme in the biosynthesis of lignins, its localization at the tissue and cellular levels is not well known. A quantitative cytochemical method has been devised to determine the localization and level of activity of this enzyme in plant tissues. Unexpectedly, the enzyme activity was present not only in the developing xylem elements and phloem fibres, but also in the epidermal and subepidermal layers of both roots and shoots. This pattern of localization implies that several distinct sites of cinnamyl alcohol dehydrogenase exist and that the role of this enzyme could be different according to the cell types in which it is located.
Improved analysis of emetic alkaloids in tissue cultures and regenerates of Cephaelis ipecacuanha by ion pair high performance liquid chromatography
Authors: Yoshimatsu Kayo , Shimomura Koichiro 
Published: March 2007

AbstractAn ion pair high performance liquid chromatographic (HPLC) system for emetic alkaloids was improved using sodium 1‐heptanesulphonate as a counter ion. This HPLC system enabled the simultaneous determination of emetine, cephaeline and protoetnetine in the leaf extract of a regenerated plant of Cephaelis ipecacuanha.