bluuebunny/crossref_metadata_2025 huggingface dataset:
Experimental and theoretical study of the homogeneous, unimolecular gas‐phase elimination kinetics of 2‐furoic acid
Authors: Ramírez Beatriz C. , Domínguez Rosa M. , Herize Armando , Tosta María , Cordova Tania , Chuchani Gabriel
Published: March 2007

The kinetics of the gas‐phase elimination kinetics of CO2 from furoic acid was determined in a static system over the temperature range 415–455°C and pressure range 20–50 Torr. The products are furan and carbon dioxide. The reaction, which is carried out in vessels seasoned with allyl bromide and in the presence of the free‐radical suppressor toluene and/or propene, is homogeneous, unimolecular, and follows a first‐order rate law. The observed rate coefficient is expressed by the following Arrhenius equation: log k1(s−1) = (13.28 ± 0.16) − (220.5 ± 2.1) kJ mol−1 (2.303 RT)−1. Theoretical studies carried out at the B3LYP/6‐31++G** computational level suggest two possible mechanisms according to the kinetics and thermodynamic parameters calculated compared with experimental values. © 2007 Wiley Periodicals, Inc. Int J Chem Kinet 39: 298–306, 2007
Solvent and substituent effects on the electrochemical oxidation of para‐ and meta‐substituted anilines
Authors: Bhuvaneshwari D. S. , Elango K. P.
Published: March 2007

Electrochemical oxidation of 15 para‐ and meta‐substituted anilines in different mole fractions of water in 2‐methylpropan‐2‐ol has been investigated in the presence of 0.1 M sulfuric acid as a supporting electrolyte. The oxidation potential data of anilines correlate well with the Brown–Okamoto's substituent constants affording a negative reaction constant. The effect of para‐ and meta‐substituents on the oxidation potential confirms to Swain's F and R, affording negative reaction constants. The oxidation potential values also correlate satisfactorily with macroscopic solvent parameter such as relative permittivity, εr. The results of Kamlet–Taft multiple correlation analysis show that specific solute–solvent interactions play a dominant role in governing the reactivity. © 2007 Wiley Periodicals, Inc. Int J Chem Kinet 39: 289–297, 2007
Alternative denervation using laser irradiation in lumbar facet syndrome
Authors: Iwatsuki Koichi , Yoshimine Toshiki , Awazu Kunio
Published: March 2007

Background and Objective

Facet syndrome is persistent low back pain that might be treated with some surgical interventions. The target of surgical techniques is the transverse process bases where the medial nerve branches innervated the facet. However, highly variable success rates have been demonstrated in different series.

Study Design/Materials and Methods

We carried out laser denervation to the dorsal surface of the facet capsule, where it is richly innervated with medial nerve branches.

Results

One year after laser denervation, 17 patients (81%) experienced complete or greater than 70% pain reduction in all 21 patients. Among the six patients who had previously undergone spinal surgery, two (33.3%) experienced successful pain relief. Overall, in four patients (19%), the response to laser denervation at 1‐year follow‐ups was not successful.

Conclusion

The dorsal surface of the facet capsule might be a more preferable target for facet denervation. Lasers Surg. Med. 39:225–229, 2007. © 2007 Wiley‐Liss, Inc.
PRKCG mutation (SCA‐14) causing a Ramsay Hunt phenotype
Authors: Visser Jasper E. , Bloem Bastiaan R. , van de Warrenburg Bart P. C.
Published: March 2007

Progressive myoclonic ataxia, also referred to as Ramsay Hunt syndrome, is characterized by a combination of myoclonus and cerebellar ataxia, infrequently accompanied by tonic–clonic seizures. Its differential diagnosis overlaps with progressive myoclonic epilepsy, a syndrome with myoclonus, tonic–clonic seizures, progressive ataxia and dementia. In patients with progressive myoclonic epilepsy, specific diseases can frequently be recognized, but the diagnostic yield in progressive myoclonic ataxia is much lower. We describe a patient who presented with multifocal myoclonus in his thirties and who later developed cerebellar ataxia and focal dystonia. His father was similarly affected. Genetic studies revealed a mutation in the protein kinase C gamma (PRKCG) gene, known to cause spinocerebellar ataxia type 14 (SCA‐14). This case illustrates that both myoclonus and dystonia are part of the clinical spectrum in SCA‐14 and that myoclonus can even be the presenting symptom. We suggest that SCA‐14 should be considered in the differential diagnosis of progressive myoclonic ataxia. © 2007 Movement Disorder Society
Primary skeletal muscle involvement in chorea‐acanthocytosis
Authors: Saiki Shinji , Sakai Koichiro , Murata Ken‐Ya , Saiki Misuzu , Nakanishi Megumi , Kitagawa Yoko , Kaito Muichi , Gondo Yuichiro , Kumamoto Toshihide , Matsui Makoto , Hattori Nobutaka , Hirose Genjiro
Published: March 2007

Chorea‐acanthocytosis (ChAc) is a hereditary disease characterized by involuntary movements and amyotrophy with elevation of serum creatine kinase. Although skeletal muscle involvement in ChAc has been suggested, the mechanism remains unclear. To investigate chorein abnormalities of the skeletal muscles of ChAc patients with an apparently heterozygous VPS13A mutation compared with those of other hereditary choreic diseases, we performed histological and immunohistochemical studies of the skeletal muscles from 3 ChAc, 1 Huntington's disease (HD), 1 McLeod syndrome (MLS), and 1 normal control (NC) with 2 originally generated anti‐chorein antibodies. Chorein immunoreactivities in HD, MLS, and NC were found linearly along the sarcolemma and appeared as speckles in the sarcoplasma, but those in ChAc were uneven and discontinuous along the sarcolemmas and increased in the sarcoplasma especially in type I fibers. This histological observation suggests chorein abnormalities of skeletal muscles might be associated with primary involvement of skeletal muscles in this disorder. © 2007 Movement Disorder Society
High performance liquid chromatographic analysis of iridoid glycosides from Penstemon rydbergii varieties
Authors: Arslanian Robert L. , Stermitz Frank R.
Published: March 2007

A new reversed phase high‐performance liquid chromatographic method was used to quantify iridoid content in plant extracts. Two varieties of Penstemon rydbergii from different locations in the Western United States were found to contain the iridoid glycosides euphroside, aucubin, geniposidic acid and plantarenaloside together with the phenylpropanoid glycoside verbascoside. While one variety showed a tenfold dominance of plantarenaloside over euphroside, the reverse was true of the other variety. The previously reported new iridoid glycoside pinifolin was shown to be an artefact from plantarenaloside since it could be isolated from a boiled extract, but not from a cold extract.
An improved high performance liquid chromatographic post‐column derivatization procedure for the UV — Vis spectroscopic characterization of phenolic compounds
Authors: Mueller‐Harvey I. , Blackwell P. M. S.
Published: March 2007

An improved method is described for the characterization of phenolic compounds using post‐column shift reagents following their separation by high performance liquid chromatography (HPLC). Modifications include the use of NaOH to adjust the pH of the column effluent, prior to introducing the AICI3 and H3BO3 reagents, and the use of commercially available spin chambers for efficiently mixing the effluent with the reagents, resulting in a negligible loss of resolution. Shifts obtained by the HPLC post‐column derivatization and the conventional procedure are comparable.
Multidimensional gas chromatography/mass spectrometry: A powerful tool for the direct chiral evaluation of aroma compounds in plant tissues I. 5‐alkanolides in fruits
Authors: Bernreuther Alexander , Bank Jürgen , Krammer Gerhard , Schreier Peter
Published: March 2007

On‐line coupled multidimensional gas chromatography (DB‐5/Lipodex D)/mass spectrometry was used for direct chiral evaluation of δ‐hexa‐, δ‐octa‐, δ‐deca‐ and, in part, δ‐dodecalactone in various fruits. Whereas in raspberry the (S)‐enantiomers predominated [enantiomeric excess (ee) values from 45.0 to 100%], the (R)‐enantimomers prevailed in apricot, coconut, greengage, mango, pineapple, plum and yellow plum (ee values from 14.4 to 100%). Variations between (S)‐ and (R)‐enantiomers depending on chain length were found in red and yellow passion fruit, peach and strawberry. δ‐Hexalactone in greengage and pineapple as well as δ‐dodecalactone in coconut were found to occur in these fruits in approximately racemic form [ee values 10.8% (R) and 4.4% (R) as well as 5.2% (R), respectively].
Quantitative characterization of the contents of Papaver somniferum latex vacuoles
Authors: Pham Thid. T. , Roberts Margaret F.
Published: March 2007

Papaver somniferum latex vacuoles were separated into two discrete fractions–‐the 900 Xg and the 1100 Xg vacuoles. The two vacuolar populations were assayed over the three‐week period of capsule maturation. Estimations of the anions sulphate, meconate and chloride, as well as the inorganic cations K+,Na+, Mg2+ and Ca2+, were made, together with measurements of the alkaloids morphine, codeine, thebaine, papaverine and noscapine. A correlation between alkaloids and organic acids has been established which supports the proposed “ion trap” mechanism proposed for alkaloid sequestration in poppy latex vacuoles.
High performance liquid chromatography and nuclear magnetic resonance analysis of longipinene derivatives from Stevia subpubescens var. intermedia
Authors: Joseph‐Nathan Pedro , Cerda‐García‐Rojas Carlos M. , Castrejón Salmantina , Román Luisa U. , Hernández Juan D.
Published: March 2007

The methodology for the separation of complex mixtures of longipin‐2‐ene‐7β, 9α‐diol‐1‐one diesters using high performance liquid chromatography followed by the identification of individual components by pulse Fourier transform 1H nuclear magnetic resonance spectroscopy is described. The identification methodology takes advantage of the spectral comparison between the isolated natural product and a wide series of previously prepared longipinene derivatives, and is applied to the study of the extracts of Stevia subpubescens var. intermedia which contain 11 previously isolated longipinene diesters and the new natural product longipin‐2‐ene‐7β, 9α‐diol‐1‐one 7‐seneciate‐9‐angelate.
Analysis of cytochalasins in cultures of Ascochyta spp. and in infected plants by high performance liquid and thin layer chromatography
Authors: Capasso Renato , Evidente Antonio , Randazzo Giacomino , Vurro Maurizio , Bottalico Antonio
Published: March 2007

High performance liquid chromatography and high performance thin layer chromatography were used in combination to check the occurrence of the bioactive cytochalasins A, B, C, D, E, H and J in cultures of some phytopathogenic species of Ascochyta, isolated from infected plants. Cytochalasins A and B were readily detected and estimated in the culture filtrates of Ascochyta heteromorpha Sch. and Sacc., the causal agent of foliar disease of oleander (Nerium oleander L.). The two compounds were also detected in oleander leaves naturally infected by A. heteromorpha suggesting that these compounds play a role in the disease of the ornamental plant. None of the above mentioned cytochalasins were detected in the culture filtrates of the other fungi tested.
Analysis of alkaloids in Chinese Ephedra species by gas chromatographic methods
Authors: Cui Jian‐Fang , Zhou Tong‐Hui , Zhang Jian‐Sheng , Lou Zhi‐Cen
Published: March 2007

The six Ephedra alkaloids (ephedrine, norephedrine, pseudoephedrine, norpseudoephedrine, methylephedrine and methylpseudoephedrine) in 12 species of Chinese Ephedra collected in 16 districts of China were separated and identified by gas chromatography combined with mass spectrometry following trimethylsilylation of the extract. The alkaloidal concentrations were determined using a gas chromatograph equipped with a nitrogen phosphorus detector. The methods described are sensitive, accurate and simple to perform.
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

l‐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

This 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

Using 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

The 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

A 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

The 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

A 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

A 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

High 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

Oxidation 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

A 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

The 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

A 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

Phenolic 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

Four 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

The 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

A 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

This 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

Kernels 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

A 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

Heptakis(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

Deficiencies 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

A 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

The 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

Free 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

A 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.
Thermospray liquid chromatography‐mass spectrometry in phytochemical analysis
Authors: Wolfender Jean‐Luc , Maillard Marc , Hostettmann Kurt
Published: March 2007

Liquid chromatography‐mass spectrometry (LC‐MS) has become a successful analytical tool and is no longer regarded as a pure research instrument without any routine practical applications. The development of the thermospray interface (TSP) has been of great help in this respect, allowing the direct use of standard HPLC conditions (1 mL/min, aqueous solvents) for the LC‐MS coupling. TSP LC‐MS has been used in phytochemical analysis as a powerful detection technique for on‐line identification and for quantification of plant constituents, even in trace amounts. Applications of this technique to different classes of plant metabolites such as polyphenols, terpenes, sugars, glucosinolates, alkaloids and glycosides are described. The potential of TSP LC‐MS in the analysis of crude plant extracts is discussed.
High performance liquid chromatographic and proton magnetic resonance spectroscopic methods for quality evaluation of Paeonia roots
Authors: Cai Y. , Phillipson J. D. , Harper J. I. , Corne S. J.
Published: March 2007

The root of several Paeonia species is one of the most frequently used plant materials in traditional Chinese medicine, and has been shown to have a variety of pharmacological properties. Owing to the differences in species, cultivation, harvesting and processing, the quality of the roots as commercial medicinal herbs varies to a considerable extent. A quantitative high performance liquid chromatographic method has been developed for the quality evaluation of Paeonia root, and a number of commercial samples have been examined. A quantitative 1H‐nuclear magnetic resonance procedure has also been developed for this purpose, and this may find a wider application in the analysis of other plant materials.
A highly sensitive quantitative determination of glutathione in plant roots by high performance gel filtration chromatography and fluorometric detection after pre‐column derivatization with N‐(7‐dimethylamino‐4‐methyl coumarinyl)‐maleimide
Authors: Obata Hitoshi , Imai Kunio , Inoue Noriyuki , Umebayashi Masanao
Published: March 2007

A convenient method was developed for the highly sensitive, quantitative determination of glutathione (GSH) using high performance gel filtration chromatography and fluorescence detection after N‐(7‐dimethylamino‐4‐methyl coumarinyl)‐maleimide modification of the peptides. The fluorescence detection method is highly sensitive and sub pmol GSH contents were detectable. This method is applicable for determining the GSH content of micro samples from higher plant roots.
Characterization of galactose from carrageenans by natural abundance site‐specific isotope parameters
Authors: Zhang Ben Li , Vallet Claude , Blanchard Frédérique , Martin Gérard J. , Combaut Georges
Published: March 2007

The overall 13C or 2H content of the organic matter of marine algae is an interesting source of information on metabolic and environmental effects experienced by aquatic plants. However, in order to appraise the complexity of the phenomena which influence the isotopic distribution, access to more specific isotopic probes is desirable. Thus, determination of the overall and site‐specific natural deuterium fingerprint of the galactose unit of carrageenans is expected to improve the characterization of these molecular species in terms of origin and history of the precursors. A strategy has been developed in order to render the galactose moiety accessible to the study of site‐specific natural isotope fractionation of hydrogen by nuclear magnetic resonance (SNIF‐NMR). Extraction and derivatization procedures have been elaborated and the possible occurrence of fractionation effects in the course of the physical and chemical transformations has been examined. By combining mass spectrometric determination of the overall isotope ratio of the galactose skeleton and analysis of the cluster signals observed in the 2H‐NMR spectra of appropriate galactose derivatives, several groups of site‐specific isotope contents can be obtained. Significant deviations with respect to a statistical distribution of deuterium in the galactose unit have been determined and the isotopic parameters of galactoses from carrageenans have been shown to differ greatly from those of galactose extracted from milk. Moreover, significant variations are observed among the different sources of carrageenans. This behaviour is consistent with the large range of overall isotope contents measured in cellulose from aquatic plants.
A selective photobiological assay to detect and quantify psoralen in Psoralea plants (Leguminosae)
Authors: Bourgaud F. , Grimal J. Y. , Nguyen C. , Bitton G. , Guckert A.
Published: March 2007

A simple and rapid bioassay involving the gram‐positive bacterium Bacillus brevis was developed to detect and quantify furocoumarins (psoralen and angelicin) in Psoralea plants (Leguminosae). Small paper discs, soaked with furocoumarin standards or the corresponding plant samples, are placed on B. brevis lawns in Petri dishes and irradiated for 24 h with UVA. The diameter of the growth inhibition zone around the discs is very well‐correlated with the quantity of furocoumarin standard in the disc. Because psoralen is more phototoxic than angelicin, its detection limit (5 × 10−8 g/disc) was lower than angelicin (5 × 10−7 g/disc). Consequently, it is possible to dilute a crude plant extract in order to reach a detectable psoralen concentration whilst maintaining the angelicin concentration below its lower detection limit. In this condition, angelicin does not interfer with psoralen detection, and the growth inhibition is entirely due to psoralen. The bioassay was validated using a classical high pressure liquid chromatographic method and the correlation between the two techniques was satisfactory with plant samples. Therefore, the bioassay can be considered as a sensitive, simple, rapid and selective method to quantify psoralen in Psoralea plants.
A method for the determination of conifer foliage protein extracted using sodium dodecyl sulphate and mercaptoethanol
Authors: Ekramoddoullah K. M. , Davidson Joanne J.
Published: March 2007

Sodium dodecyl sulphate and mercaptoethanol are commonly used for extraction and solubilization of proteins, but these substances interfere with previously reported methods for the quantitation of small amounts of protein. In order to overcome this difficulty, a method has been developed for assaying small quantities of protein by (i) spotting the protein solution on a polyvinylidene difluoride membrane, (ii) staining the membrane bound protein with Coomassie Blue, (iii) destaining, and (iv) determining the optical density of the stained membrane by laser‐based scanning. The determination of proteins in conifer foliage by this method is described.
Analysis of crude extracts and fractions of brazilian polypodiaceae by high‐resolution gas chromatography‐mass spectrometry. I. triterpenes
Authors: Patitucci Maria Lucia , Pinto Angelo C. , Cardoso Jari N.
Published: March 2007

Characterization of individual components in plant extracts through classical phytochemical methods is a multi‐step procedure which is both costly and time‐consuming. Also significant amounts of extract are required and detection of minor compounds is frequently not possible. The method described in this work involves direct analysis of crude or prefractioned apolar or medium‐polar extracts by high‐resolution gas chromatography and computerized high resolution gas chromatography‐mass spectrometry, followed by co‐injections of the crude extract with certified standards on capillary columns of different polarities. The effectiveness of the method is illustrated for several species of Polypodiaceae (spores and rhizomes). allowing easy monitoring of compound‐type distributions (e.g. triterpenes) and detection of structures present at trace levels (for example, 22,29,30‐trisnorhopane).
Culture and the behavioural manifestations of traits: an application of the Act Frequency Approach
Authors: Church A. Timothy , Katigbak Marcia S. , Miramontes Lilia G. , del Prado Alicia M. , Cabrera Helena F.
Published: March 2007

The behavioural manifestations of Big Five traits were compared across cultures using the Act Frequency Approach. American (n = 176) and Filipino (n = 195) students completed a Big Five measure and act frequency ratings for behaviours performed during the past month. Acts for specific traits cohered to an equivalent degree across cultures. In both cultures, the structure of act composites resembled the Big Five and the strength of trait‐behaviour relationships was very similar. Many acts were multidimensional and analyses revealed cultural commonalities and differences in the relevance and prevalence of acts for the Big Five traits. The results were more consistent with trait than cultural psychology perspectives, because traits predicted behaviour equally well, on average, in the two cultures. Copyright © 2007 John Wiley & Sons, Ltd.
π‐conjugated polymers having diaza[12]annulene rings and aminopenta‐2,4‐dienylidene groups generated by the ring opening of pyridinium rings
Authors: Yamaguchi Isao , Gobara Yoshiaki , Sato Moriyuki
Published: March 2007

Reactions of N‐(2,4‐dinitrophenyl)pyridinium chloride with 2,5‐dimethyl‐1,4‐phenylenediamine in 1:2, 1:1.5, 1:1, and 2:1 molar ratios caused the ring opening of the pyridinium ring and thereby yielded polymers (P1–P4) consisting of 5‐(2,5‐dimethyl‐1,4‐phenylene)penta‐2,4‐dienylideneammonium chloride (unit A) and N‐2,5‐dimethyl‐1,4‐phenylene diaza[12]annulenium dichloride (unit B). The 1H NMR spectra suggested that the composition ratios of unit A to unit B in P1–P4 were 0.98:0.02, 0.94:0.06, 0.81:0.19, and 0.79:0.21, respectively. P1–P4 showed an absorption maximum (λmax) at a longer wavelength than the monomers because of the expansion of the π‐conjugation system. Films of P3 and P4 showed λmax at a considerably longer wavelength than those in solution, and this was attributable to the ordered structures of the polymers in the solid state. Powder X‐ray diffraction analysis supported the ordered structures of P3 and P4. Pellets molded from P3 and P4 exhibited a metallic luster, whereas those from P1 and P2 did not show such a luster. Cyclic voltammetry measurements indicated that P1–P4 were electrochemically active in films. The thermal stability of the polymers depended on the composition ratios of unit A to unit B. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 1507–1514, 2007
2‐D DIGE and MALDI‐TOF‐MS analysis of the serum proteome in human osteosarcoma
Authors: Jin Song , Shen Jing‐Nan , Guo Qian‐Chen , Zhou Jia‐Guo , Wang Jin , Huang Gang , Zou Chang‐ye , Yin Jun‐qiang , Liu Shao‐Jun , Liu Wei , Li Ming‐Tao , Wang Li‐Na
Published: March 2007

We performed 2‐D DIGE on proteins prepared from serum obtained from patients with osteosarcoma (OS) and controls, to identify differentially expressed proteins that might serve as serum biomarkers for OS prognosis. Proteins found to be differentially expressed were identified by MALDI‐TOF mass spectrometric analysis, coupled with database interrogation. We compared serum samples from four individuals with OS to four age‐ and sex‐matched healthy controls. We identified 24 protein spot‐features that were significantly increased, and 34 that were significantly decreased in serum from patients with OS relative to the controls. The MS analysis revealed 18 unique proteins that were increased, and 25 unique proteins that were decreased in OS serum samples. Western blot and ELISA analysis confirmed increased levels of amyloid‐related serum protein (SAA) in the OS serum samples. The increased expression levels of SAA were decreased after using MTX and cisplatin combination chemotherapy, and were further decreased after operation. Moreover, increased expression levels of sera SAA were seen in the relapsed patients. Our results suggested that the determination of serum SAA in OS patients might be utilized as a marker for relapse and in evaluation of the efficacy of therapy.