bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparison of radioimmunoassay and capillary gas chromatography in the analysis of l‐hyoscyamine from plant material
Authors: Martinsen Aarne , Naaranlahti Toivo , Turkia Marja Liisa , Lehtola Timo , Oksanen Jari , Ylinen Markku 
Published: March 2007

Abstractl‐Hyoscyamine in the roots of Atropu belladonna L. was assayed by capillary gas chromatography (CCC). When the extraction and analysis were evaluated using a radioimmunoassay (RIA) established for l‐hyoscyamine, the two methods were found to be positively and significantly correlated. Important characteristics of CCC and RIA methods in tropane alkaloid analysis of plant material are discussed. A prominent cross‐reaction for apoatropine, a constituent of A. belladonna roots and leaves, was found in this study. This cross‐reaction has not been investigated in other studies of hyoscyamine RIA.
Simultaneous determination of atropine and scopolamine in plants by mixed‐column high performance liquid chromatography
Authors: Mandal S. , Naqvi A. A. , Thakur R. S. 
Published: March 2007

AbstractThis paper describes a simple and rapid high performance liquid chromatographic method using two different polarity columns in series for the quantitative analysis of the major tropane alkaloids atropine and scopolamine. The problems associated with the simultaneous determination of the two alkaloids in plant extracts have been overcome. The method has been successfully applied to the analysis of three species of Solanaceous plants.
Stereoisomeric flavour compounds. LII: Separation and structure elucidation of the furanoid linalool oxide stereoisomers using chirospecific capillary gas chromatography and nuclear magnetic resonance spectroscopy
Authors: Askari Christiane , Mosandl Armin 
Published: March 2007

AbstractUsing heptakis(2,3,6‐tri‐O‐methyl)‐β‐cyclodextrin as the chiral stationary phase in capillary gas chromatography, the direct stereodifferentiation of the four furanoid linalool oxide stereoisomers has been achieved. The structure elucidation of the two geometrical isomers by 1H NMR spectroscopy (including intramolecular nuclear Overhauser effects of the separated diastereomers) is now reported. The elution order of the optical isomers is ascertained by synthesis and chromatography of the (2R)‐configured diastereomers, starting from (R)‐linalool.
Analysis of artemisinin and related sesquiterpenoids from artemisia annua L. by combined gas chromatography/mass spectrometry
Authors: Woerdenbag Herman J. , Pras Niesko , Bos Rein , Visser Jan F. , Hendriks Henk , Malingré Theo M. 
Published: March 2007

AbstractThe sesquiterpenoid artemisinin (3) and its biosynthetic precursors arteannuic acid (1), arteannuin B (2) and artemisitene (4) can be separated and identified by combined gas chromatography/mass spectrometry both as a mixture of reference standards as well as in extracts of Artemisia annua L. From this study a generally applicable gas chromatographic method has been developed for the analysis of these sesquiterpenoids in A. annua. Analysis of plant parts revealed that the highest sesquiterpenoid concentrations were present in the leaves, buds and small green stems, while the main stem contained only small amounts. Low levels of arteannuic acid and arteannuin B were present in the side‐roots. No sesquiterpenoids could be detected in the main root and none of the plant parts accumulated detectable quantities of artemisitene.
Evidence for self‐association of the anthocyanin petanin in acidified, methanolic solution using two‐dimensional nuclear overhauser enhancement NMR experiments and distance geometry calculations
Authors: Nerdal Willy , Andersen Øyvind M. 
Published: March 2007

AbstractA new mechanism is decribed for self‐association of anthocyanins in solution. Petanin, petunidin 3‐O‐[6‐O‐(4‐O‐E‐p‐coumaroyl‐α‐L‐rhamnopyranosyl)‐β‐D‐glucopyranoside]‐5‐O‐β‐D‐glucopyranoside, was studied in acidified methanolic solution using the nuclear Overhauser enhancement (NOESY) nuclear magnetic resonance technique. Intra‐ and inter‐molecular NOESY cross‐peaks were observed, and the corresponding proton‐proton distance bounds were used in distance geometry calculations to determine the stacking of the petanin aglycones. The orientation of two self‐associated petanin aglycones was found to be head‐to‐tail along both the long and the short aglycone axis. Lack of observed NOESY cross‐peaks between protons of the coumaroyl group and the aglycone indicated absence of intramolecular stacking of the stable petanin molecules. Non‐coplanarity between the planes of the benzopyrylium and the phenyl rings was also indicated.
Comparative spectroscopic characterization of synthesized isomers of di‐O‐methylated ellagic acids
Authors: Sato Tsuguo 
Published: March 2007

AbstractThe determination of the isomeric 3,3′‐, 4,4′‐ and 3,4‐di‐O‐methylellagic acid derivatives by high performance liquid chromatography and ultraviolet, nuclear magnetic resonance and infrared spectroscopy is described.
High performance liquid chromatography of non‐protein amino acids extracted from Acacia seeds
Authors: Shah A. J. , Younie D. A. , Adlard M. W. , Evans C. S. 
Published: March 2007

AbstractA sensitive, reversed phase, high performance liquid chromatographic procedure for the analysis of non‐protein amino acids has been developed. The method is based on precolumn derivatization with 9‐fluoroenylmethyl chloroformate of the non‐protein amino acids characteristic of seeds of Acacia species, namely N‐acetyldjenkolic acid, diaminopropionic acid and diaminobutyric acid and their acetyl, ureido and oxalyl N‐substituted derivatives. The separation of derivatives was achieved by means of a gradient elution programme utilizing two buffers of different pH values and acetonitrile. Following separation, the derivatized amino acids were detected spectrofluorometrically. The levels of non‐protein amino acids in seeds of Acacia species, which were representative of three taxonomically distinct groups, were measured by analysis of ethanol extracts.
A quantitative method for the estimation of parthenolide and other sesquiterpene lactones containing α‐methylenebutyrolactone functions present in feverfew, Tanacetum parthenium
Authors: Dolman David M. , Knight David W. , Salan Umit , Toplis Dane 
Published: March 2007

AbstractA sensitive and quantitative assay of parthenolide and other sesquiterpene lactones containing an α‐methylenebutyrolactone residue which are present in Feverfew, Tanacetum parthenium, has been developed. This is based on Michael additions of alkylthiols containing a large chromophore to the latter function. A particularly suitable derivatizing agent is 9‐thiomethylanthracene. The adducts are analysed accurately and with great sensitivity using high performance liquid chromatograph coupled with ultraviolet detection.
Characterization of acylated steryl glycosides from Euryale ferox by nuclear magnetic resonance spectroscopy
Authors: Haoru Zhao , Shoushun Zhao 
Published: March 2007

AbstractHigh resolution nuclear magnetic resonance spectroscopy has been used to identify the main acylated steryl glycosides isolated from Euryale ferox as 24‐ethylcholest‐5‐en‐3β‐O‐β‐D‐pyranoglucosyl palmitate and 24‐ethylcholesta‐5,22E‐dien‐3β‐O‐β‐D‐pyranoglucosyl palmitate. The application of this technique to the identification of acylated steryl glycosides within complex mixtures is described.
Preparation of radioactively labelled isodityrosine
Authors: Miller Janice G. , Fry Stephen C. 
Published: March 2007

AbstractOxidation of L‐[U‐14C]tyrosine with 2.7 molar equivalents of alkaline hexacyanoferrate(III) yielded at least 12 chromatographically mobile oxidation products and a large amount of immobile material. Use of 0.23 molar equivalents of hexacyanoferrate(III) yielded [14C]dityrosine (∼1.3% of added [14C]tyrosine) and [14C]isodityrosine (∼0.6%). A chromatographic method is described for the isolation of these two products from the mixture. A method is also described for the prepration of [3H]isodityrosine from non‐radioactive isodityrosine by catalytic exchange with 3H2. The [3H]isodityrosine formed was essentially stable in 6M HCI at 110°C, indicating that the tritiation occurred at the benzylic groups.
Benzoylation and high performance liquid chromatographic detection of solasodine
Authors: Drewes F. E. , Van Staden J. , Drewes S. E. 
Published: March 2007

AbstractA rapid technique for the determination of solasodine by high performance liquid chromatography (HPLC) following derivatization of the steroidal alkaloid by benzoyl chloride has been developed. In the presence of a 5 M excess of benzoyl chloride, the reaction proceeds to completion in 6 h at 50°C. The levels of benzoylated solasodine can be determined by HPLC at a wavelength of 254 nm, there being a linear relationship between the amount of solasodine injected and the peak area produced. Microgram quantities of solasodine can be detected in this way. The benzoylated product is very stable.
Capillary gas chromatography‐spectroscopic techniques in natural product analysis
Authors: David F. , Sandra P. 
Published: March 2007

AbstractThe current state of the art in capillary gas chromatography (CGC), CGC‐mass spectroscopy (CGC‐MS), CGC‐Fourier transform infrared spectroscopy (CGC‐FTIR) and CGC‐atomic emission detection (CGC‐AED) is discussed with emphasis on their routine applicability in natural product analysis as experienced in the laboratories of the authors.
Quantitation of pterosins A and B, and ptaquiloside, the main carcinogen of pteridium aquilinum (L. Kuhn), by high pressure liquid chromatography
Authors: Alonso‐Amelot Miguel E. , Pérez‐Mena Margarita , Calcagno Maria Pia , Jaimes‐Espinoza Ramón 
Published: March 2007

AbstractA quantitative method for the assessment of ptaquiloside and pterosins A and B in bracken fern has been developed. The technique involves quantitative extraction of fresh plant tissue, base‐induced decomposition of ptaquiloside to pterosin B, followed by prepurification of products on a silica gel microcolumn and quantitative high pressure liquid chromatography. The method has been used to estimate the contents of these norsequiter‐penes in fronds and rhizomes of Pteridium aquilinum var. caudatum from northern South America.
Analytical in source pyrolytic methylation electron impact mass spectrometry of phenolic acids in biological matrices
Authors: Mulder Marcel M. , Van Der Hage Erik R. E. , Boon Jaap J. 
Published: March 2007

AbstractPhenolic acids in complex biological matrices are easily decarboxylated under pyrolysis electron impact (EI) conditions depending on their binding to other plant cell wall compounds. Pyrolysis gas chromatography/mass spectrometry (Py‐GC/MS) of phenolic acids reveals only the decarboxylated compound but this product may also be derived from the alcoholic lignin monomers. Discrimination between the acidic and alcoholic phenol can be obtained by stabilization of the molecular ion of the two compounds. Samples of p‐coumaric acid, of sporopollenin from Pinus pollen wings, of bamboo milled wood lignin (MWL) and of tobacco leaf nerve MWL were analysed by analytical Py‐EIMS. Mass peaks for the molecular ion of p‐coumaric acid and of the decarboxylated product may be observed. Results are compared with Py‐MS data of samples treated with tetramethylammonium hydroxide (TMAH), a compound used to methylate the phenolic hydroxyl group and the carboxyl group of the phenolic acid in the ion source of the mass spectrometer. Mass spectra of samples treated with this agent show a high content of double methylated p‐coumaric acid (m/z 192). TMAH treatment allows discrimination between phenolic acids and alcohols under Py‐MS and Py‐GC/MS conditions by producing more stable molecular ions.
Acetylated saponins with molluscicidal activity from Sapindus rarak: Unambiguous structure determination by proton nuclear magnetic resonance and quantitative analysis
Authors: Hamburger Matthias , Slacanin Ivan , Hostettmann Kurt , Dyatmiko Wahjo , Sutarjadi  
Published: March 2007

AbstractFour monodesmosidic triglycosides, bearing up to two acetyl moieties on the terminal sugar, have been isolated from the pericarp of fruits of Sapindus rarak DC (Sapindaceae). The positions of the acetyl groups and interglycosidic linkages have been established by proton nuclear magnetic resonance spectroscopy, including double‐quantum filtered phase‐sensitive COSY and homonuclear Overhauser enhancement difference measurements. A method for the qualitative analysis of saponins by reversed phase high pressure liquid chromatography (HPLC) has been developed. The total saponin content was determined by HPLC analysis of hederagenin liberated by acidic hydrolysis of the methanolic extract. The molluscicidal activity (LC100/24h) of the saponins ranges from 6.25 to 12.5 ppm.
Structural and conformation analysis of sesquiterpene lactones by proton nuclear magnetic resonance
Authors: Silva Gloria L. , Gil Roberto R. , Sosa Virginia E. , Suárez Angela R. 
Published: March 2007

AbstractThe stereochemistry as well as the conformation of two germacranolides and two 3,4‐epoxyguaianolides were determined by computational methods employing LAOCOON‐III and DAERM programs. The chair‐chair conformation was shown to be preferred by the germacranolide macrocycle in solution, while the A‐ring of 1,10‐dehydro‐3,4‐epoxyguaianolides was shown to be approximately planar. The ten‐membered ring stereochemistry of germacranolides was deduced from the calculated results.
A simple thin layer chromatographic method to detect the main polyphenols occurring in olive oil vegetation waters
Authors: Capasso Renato , Evidente Antonio , Scognamiglio Francesco 
Published: March 2007

AbstractA thin layer chromatographic (TLC) method has been developed to detect the major polyphenols (the main pollutants) in olive oil vegetation waters. The method involves reversed phase TLC (C18‐TLC) and silica gel high performance TLC (Si‐HPTLC) on the organic extracts of oil vegetation waters (VW), using catechol, 4‐methylcatechol, tyrosol, hydroxytyrosol and oleuropein as standards. Using Si‐HPTLC analysis it is possible to detect only tyrosol and hydroxytyrosol, whilst with C18‐TLC analysis all of the main polyphenols present except oleuropein can be detected. Confirmation of the identities of the polyphenolic compounds was obtained by C18‐TLC and Si‐HPTLC analysis of the acetylated organic extracts of VW together with the more stable acetyl derivatives of the phenols as standards.
Quantitative determination of triacylglycerols in plant tissues
Authors: Sotres Rogelio Rodrigues , Black Michael 
Published: March 2007

AbstractThis paper describes the estimation of triacylglycerol (TAG) in wheat embryos by a method based on the determination of glycerol. Modifications have been made to the method currently in use for serum TAGs to make it suitable for application with plant tissues, particularly the substitution of a chemical hydrolysis of TAG in place of the enzymatic lipolysis. The method is relatively rapid, highly reproducible and gives results which are in close agreement to those obtained by analysis of the fatty acid methyl esters. There is no interference by other glycerol‐containing compounds such as phospholipids or glycerol phosphates. Examples are given of the method applied to wheat embryos accumulating TAG in planta or treated in vitro in different ways.
Quantification of benzaldehyde and its precursors in montmorency cherry (Prunus cerasus L.) kernels
Authors: Chandra Amitabh , Nair Muraleedharan G. 
Published: March 2007

AbstractKernels from Michigan‐grown tart cherry Prunus cerasus L. cv. Montmorency were frozen at −40°C, lyophilized, crushed and extracted sequentially with hexane and methanol. Amygdalin, mandelonitrile and benzaldehyde were present in the kernel extracts and were quantified by high performance liquid chromatography. Amygdalin was found to be the major component, while free mandelonitrile is detected for the first time in the tart cherry pit kernels.
Isolation by asymmetric polymerase chain reaction and partial sequencing of the common bean chloroplast trnL (UAA) gene and pseudogene
Authors: Mubumbila Mfik A. V. , Carelse Orseline , Kempf Jules 
Published: March 2007

AbstractA polymerase chain reaction (PCR) strategy has been developed which utilizes the common bean (Phaseolus vulgaris) chloroplast DNA as a template and primers from (a) the 5′ exon of the broad bean chloroplast trnL (UAA) gene (EMBL ac no. X51471) and (b) the 3′ exon of the common bean chloroplast trnL (UAA) pseudogene (EMBL ac no. X58537). A 600 bp PCR Product was reamplified using the 5′ exon primer and an internal primer from the 5′ end of the intron of the common bean chloroplast trnL (UAA) pseudogene. A 130 bp PCR Product was separated into 130 bp and 106 bp DNA fragments on an 8% non‐denaturing polyacrylamide gel. Both fragments were purified by phenol extraction, reamplified by asymmetric PCR reactions and directly sequenced by the Sanger method. When compared to the broad bean trnL (UAA) gene, the 130 bp PCR product showed sequence homologies of 100% with its 5′ exon and 79% over the first 58 nucleotides of the 5′ end of the intron. The 106 bp PCR product contained deletions in its 5′ exon region. These results indicated that the PCR technique had isolated the trnL (UAA) gene and its pseudogene.
Stereoisomeric flavour compounds. LXIV: The chirospecific analysis of 2‐alkyl‐branched flavour compounds from apple headspace extracts and their sensory evaluation
Authors: Karl Volker , Dietrich Armin , Mosandl Armin 
Published: March 2007

AbstractHeptakis(2,3‐di‐O‐methyl‐6‐O‐tert‐butyldimethylsilyl)‐β‐cyclodextrin (DIME‐β‐CD) is shown to be an efficient stationary phase of high enantioselectivity towards chiral esters. Different 2‐alkyl‐branched esters have been stereoanalysed using DIME‐β‐CD in enantioselective capillary gas chromatography. The olfactory properties of the enantiomeric pairs are also described.
An improved methylation procedure for the analysis of complex polysaccharides including resistant starch and a critique of the factors which lead to undermethylation
Authors: Needs P. W. , Selvendran R. R. 
Published: March 2007

AbstractDeficiencies in the widely used Hakomori method of methylation are described. Evidence is given that this method of linkage analysis often gives levels of undermethylation which hamper the detailed study of complex carbohydrates from plant cell walls. A modified method using sodium hydroxide as base is described which is capable of fully methylating polymers for which the Hakomori method generally fails and which does not promote the carbohydrate oxidation typical of a former procedure using this reagent. An explanation of its efficacy is advanced. Analyses of retrograded, α‐amylase‐resistant starches obtained by the modified method are reported.
The analysis of S‐alk(en)yl‐L‐cysteine sulphoxides (flavour precursors) from species of Allium by high performance liquid chromatography
Authors: Edwards S. J. , Musker D. , Collin H. A. , Britton G. 
Published: March 2007

AbstractA method of extraction, purification and separation has been developed for the determination of the alk(en)yl‐L‐cysteine sulphoxides in species of Allium, Alliinase was inhibited during extraction by the addition of 10 mM hydroxylamine. The sulphoxides were separated from the crude extract by passage through an Amberlite IR 120 anion exchange column (H+ form) eluted with 2 M NH4OH, and further purified by high performance liquid chromatography (HPLC) on two Spherisorb columns S5ODS2 in series. The major sulphoxide component found in garlic was (+)‐S‐allyl‐L‐cysteine sulphoxide (>95%); in onion, trans‐(+)S‐1‐propenyl‐L‐cysteine sulphoxide accounted for 78% of the total sulphoxides extracted, and in chives (+)‐S‐methyl‐L‐cysteine sulphoxide was the major component (65%). The analysis provides a sensitive and routine method for estimating the sulphoxide flavour precursors in the Allium species.
Quantitative analysis of gibberellins by isotope dilution mass spectrometry: A comparison of the use of calibration curves, an isotope dilution fit program and arithmetical correction of isotope ratios
Authors: Croker Stephen J. , Gaskin Paul , Hedden Peter , MacMillan Jake , MacNeil Kenneth A. G. 
Published: March 2007

AbstractThe quantitative analysis of gibberellin A1 (GA1) in apices of 19‐day‐old seedlings of Pisum sativum L. cultivar Alaska is described using isotope dilution mass spectrometry. Three methods are compared for determining the dilution of isotope in the internal standards, [17‐2H2]GA1 and [2β‐2H1]GA1. Similar results were obtained with each method. The use of calibration curves gave the most precise determination with [2H2]GA1 as internal standard irrespective of the amount added. The use of an isotope dilution fit program was more precise using [2H1]GA1 as internal standard. A simpler arithmetical correction procedure gave consistently higher estimates with both internal standards. The relative merits of the methods are discussed and the requirements for reliable quantification by isotope dilution gas chromatography‐mass spectrometry are presented.
Pico‐tag analysis of arogenic acid and related free amino acids from plant and fungal extracts
Authors: Razal Ramon A. , Lewis Norman G. , Towers G. H. Neil 
Published: March 2007

AbstractFree amino acids from various plant tissues and fungal mycelia were extracted with buffered ethanol (75%, v/v) in 0.5% 2‐amino‐2‐methyl‐1‐propanol‐hydrochloride pH 11.0. Following removal of proteins and other high molecular weight components by ultrafiltration, free amino acids in the extracts were dried, derivatized with phenylisothiocyanate and analysed by high performance liquid chromatography using a Waters Pico‐Tag column. Arogenic acid, a non‐aromatic amino acid precursor of phenylalanine and tyrosine, was not detected although both aromatic amino acids were quantitated in all plant and fungal extracts. Nevertheless, arogenic acid in the mycelium of a triply‐blocked mutant ofNeurospora crassawas readily detected. It is proposed that the absence of arogenic acid in plant extracts suggests that this intermediate does not accumulate in the metabolic pool thereby negating a possible regulatory role during aromatic amino acid biosynthesis.
Reverse phase high pressure liquid chromatographic separation of permethylated free and glucosylated gibberellins: A method for the analysis of gibberellin metabolites
Authors: Schneider G. , Schaller B. , Jensen E. 
Published: March 2007

AbstractA new strategy for simultaneous analysis of both free gibberellins (GAs) and gibberellin‐O‐glucosides (GA‐O‐glucosides) in plant extracts is described. The procedure, which avoids liquid‐liquid partitioning comprises the following sequential steps, applied to the aqueous residue of an 80% aqueous methanol extract: (a) ion exchange chromatography; (b) permethylation; (c) silica gel chromatography; (d) preparative reverse phase high pressure liquid chromatography; (e) gas chromatography‐mass spectrometry. The method has been used to analyse the acidic metabolites of [17‐2H2]GA20, applied to normal and dwarf‐1 Zea mays. In normal plants the label was found to be incorporated into GA29, GA1, GA8, GA20‐13‐O‐glucoside, GA29‐2‐O‐glucoside, GA29‐13‐O‐glucoside, and GA8‐2‐O‐glucoside. In dwarf‐1 mutant plants the label was incorporated into GA29, GA20‐13‐O‐glucoside, and GA29‐2‐O‐glucoside.