bluuebunny/crossref_metadata_2025 huggingface dataset:
MR‐guided ablation of hepatocellular carcinoma aided by gadoxetic acid
Authors: Bathe Oliver F. , Mahallati Houman
Published: March 2007

Local recurrences are problematic following radiofrequency ablation (RFA) of hepatocellular carcinoma. Intraoperative magnetic resonance imaging (iMRI) is a potentially useful tool for the assessment of the extent of the thermal injury produced by RFA. The use of gadoxetic acid disodium, a hepatocyte‐specific contrast agent with prolonged retention, is described as a method of improved assessment of the ablative margins relative to the tumor margins. J. Surg. Oncol. 2007;95:670–673. © 2007 Wiley‐Liss, Inc.
Modified radiofrequency‐assisted liver resection: A new device
Authors: Zacharoulis Dimitris , Tzovaras George , Rountas Christos , Poultsidis Antigoni , Katsogridakis Emmanuel , Sioka Eleni , Hatzitheofilou Constantine
Published: March 2007

Background

Radiofrequency ablation (RF) is emerging as new therapeutic method for the management of hepatic tumors. So far the RF‐assisted hepatectomy has been described using an electrode initially designed for ablation of unresectable tumors. Herein, we describe a new technique for liver resection using a bipolar radiofrequency device.

Method

Ten patients undergo liver resection using a bipolar radiofrequency device. A minimal zone of desiccation around the tumor is created between pairs of opposing electrodes as a result of a minimum amount of energy released. This coagulated plane can be divided with a scalpel.

Results

The liver parenchyma was divided with minimal blood loss. No intensive care unit admission was needed. There was no postoperative biliary leak or any other septic complication.

Conclusion

The technique is safe and feasible, simplifies liver resection and appears to be associated with minimal morbidity and maximum liver parenchyma preservation. J. Surg. Oncol. 2007;96: 254–257. © 2007 Wiley‐Liss, Inc.
What is the best treatment modality for adrenal metastasis from hepatocellular carcinoma?
Authors: Park Joon Seong , Yoon Dong Sup , Kim Kyung Sik , Choi Jin Sub , Lee Woo Jung , Chi Hoon Sang , Kim Byong Ro
Published: March 2007

Purpose

This study aimed to analyze the effect of each therapeutic modality to clarify the treatment strategy for adrenal metastases from hepatocelluar carcinoma (HCC).

Methods

Adrenal metastasis from HCC was observed in 45 patients. Fifteen patients who were determined to have multi‐organ metastasis including the adrenal glands were excluded, and the remaining 30 patients were reviewed.

Results

The location of adrenal metastasis was right side, left side, and both in 17, 9, and 4 patients, respectively. Treatment for adrenal metastasis consisted of adrenalectomy in 5 patients, non‐surgical treatment such as TACE, or chemotherapy and radiotherapy in 19 patients, while 6 patients received no treatment. The median survival duration was 11.05 months in the 30 patients with adrenal metastasis. In the 25 patients with well‐controlled intrahepatic lesions, the median survival time of those patients who received adrenalectomy, non‐surgical treatment, and no treatment was 21.41, 11.05, and 5.64 months, respectively. The difference in cumulative survival according to mode of treatment of adrenal metastasis in the well‐controlled intrahepatic lesion group was statistically significant.

Conclusion

We envisage increased benefit after adrenalectomy in terms of survival in patients with well controlled intrahepatic lesions at the time of adrenal metastasis and good general medical condition. J. Surg. Oncol. 2007;96:32–36. © 2007 Wiley‐Liss, Inc.
Barriers to rehabilitation of colorectal cancer patients
Authors: Rodriguez‐Bigas Miguel A. , Chang George J. , Skibber John M.
Published: March 2007

Background

Colorectal cancer is one of the most common cancers in the United States. Since 1993 there has been a decrease in colorectal cancer mortality. Thus, there are more cancer survivors. In this manuscript potential barriers encountered during the rehabilitation of the colorectal cancer patient will be discussed.

Methods

A literature review of manuscripts dealing with the rehabilitation and quality of life of the colorectal cancer patient was performed with specific emphasis on barriers for rehabilitation.

Results

There is not much literature regarding barriers to the rehabilitation of the colorectal cancer patient. The rehabilitation of the colorectal cancer patient is a complex continuum. In order to maximize the potential for rehabilitation a team approach where the patient, family, friends and health care providers participate actively should be undertaken. The most common barriers are in the domains of knowledge, patient, health care system, and therapy. The impact of these barriers will vary from patient to patient.

Conclusions

There is a paucity of literature regarding barriers to the rehabilitation of the colorectal cancer patient. Prospective databases as well as prospective longitudinal studies need to be established so that the barriers that colorectal cancer patients encounter during their rehabilitation are more clearly identified and understood. J. Surg. Oncol. 95:400–408. © 2007 Wiley‐Liss, Inc.
Barriers to rehabilitation of the neurosurgical spine cancer patient
Authors: Stubblefield Michael D. , Bilsky Mark H.
Published: March 2007

The treatment of metastatic spine tumors has evolved significantly over the past 20 years due largely to improvements in magnetic resonance imaging; decompressive surgical techniques, spinal instrumentation, and high‐dose conformal radiation. These advances have improved our ability to provide meaningful palliation for patients who often have significant medical and cancer‐related issues. Despite technical advances that have improved our ability to maintain neurologic function, stabilize the spine, and prevent local tumor recurrences, significant barriers to rehabilitation remain. This article reviews these primary barriers to rehabilitation of the cancer patient following spine surgery and emphasizes the importance of diagnostic accuracy and a comprehensive team approach to the treatment of pain and other disorders in this population. J. Surg. Oncol. 95:419–426. © 2007 Wiley‐Liss, Inc.
The effects of childhood trauma on daily mood lability and comorbid psychopathology in bulimia nervosa
Authors: Wonderlich Stephen A. , Rosenfeldt Steven , Crosby Ross D. , Mitchell James E. , Engel Scott G. , Smyth Joshua , Miltenberger Raymond
Published: March 2007

A study of bulimic women examined the relationship between histories of childhood trauma and psychiatric disorders, as well as daily measures of mood and behavior. One hundred twenty‐three women with bulimia nervosa were assessed with interviews and completed an Ecological Momentary Assessment (EMA) protocol in which they carried a palmtop computer for 2 weeks. Sexual abuse was associated with a history of mood and anxiety disorders, and emotional abuse with eating disorder psychopathology. In the EMA assessment, sexual abuse was associated with daily purging frequency and self‐destructive behavior. Emotional abuse was associated with average daily mood and mood lability. These findings support the idea that child maltreatment may be associated with various aspects of bulimia‐related psychopathology.
Risk and resilience factors for posttraumatic stress symptomatology in Gulf War I veterans
Authors: Vogt Dawne S. , Tanner Lynlee R.
Published: March 2007

What factors distinguish war‐exposed veterans who experience posttraumatic stress symptomatology (PTSS) from those who do not? This study used structural equation modeling procedures to examine the complex interplay among predeployment, war‐zone, and postdeployment factors as they relate to PTSS in a sample of Gulf War I veterans. A primary goal was to determine to what extent previously documented associations among Vietnam veterans would replicate in this more contemporary veteran cohort. Results supported a multivariate etiological perspective on PTSS, with war‐zone factors accounting for the largest proportion of variance in PTSS. The majority of hypothesized associations held, suggesting that the mechanisms underlying PTSS may be similar across veteran cohorts.
Conduct disorder, war zone stress, and war‐related posttraumatic stress disorder symptoms in American Indian Vietnam veterans
Authors: Dillard Denise , Jacobsen Clemma , Ramsey Scott , Manson Spero
Published: March 2007

This study examined whether conduct disorder (CD) was associated with war zone stress and war‐related post‐traumatic stress disorder (PTSD) symptoms in American Indian (AI) Vietnam veterans. Cross‐sectional lay‐interview data was analyzed for 591 male participants from the American Indian Vietnam Veterans Project. Logistic regression evaluated the association of CD with odds of high war zone stress and linear regression evaluated the association of CD and PTSD symptom severity. Childhood CD was not associated with increased odds of high war zone stress. Conduct disorder was associated with elevated war‐related PTSD symptoms among male AI Vietnam Veterans independent of war zone stress level and other mediators. Future efforts should examine reasons for this association and if the association exists in other AI populations.
Kinetics study of propyl acetate synthesis reaction catalyzed by Amberlyst 15
Authors: Huang Yuan‐Sheng , Sundmacher Kai
Published: March 2007

The reaction kinetics of esterification of acetic acid with n‐propanol was investigated. The reaction was catalyzed by the commercial cation‐exchange resin Amberlyst 15, and the kinetic data were obtained in a batch reactor within the temperature range 338–368 K. The chemical equilibrium constant, Keq, was first determined experimentally; the result shows that Keq is about 20 and slightly temperature dependent. Altogether 14 sets of kinetic data were then measured. The influences of operating parameters such as temperatures, initial molar ratios, and catalyst concentrations were checked. The pseudo‐homogeneous (PH), Rideal–Eley (RE), and Langmuir–Hinshelwood–Hougen–Watson (LHHW) kinetic models were developed to interpret the obtained kinetic data. The parameters of the kinetic models were identified by the software DIVA, and the confidence interval of each parameter was also estimated. Both the chemical equilibrium constant and kinetic models were formulated in terms of the liquid phase activity, which was described by the nonrandom two‐liquid (NRTL) model. The LHHW model gives the best fitting result, followed by the RE model and the PH model, whereas the confidence intervals rank in the reverse order. In addition, an effective solution was proposed to overcome a convergence problem occurring in the LHHW model parameter identification, which has been reported several times in the literature. © 2007 Wiley Periodicals, Inc. Int J Chem Kinet 39: 245–253, 2007
Rate constants for aqueous‐phase reactions of SO4− with C2F5C(O)O− and C3F7C(O)O− at 298 K
Authors: Kutsuna Shuzo , Hori Hisao
Published: March 2007

Perfluorocarboxylic acids and their anions (PFCAs), such as perfluorooctanate (C7F15C(O)O−), have been generally recognized to be global pollutants and are believed to persist in the environment. Kinetic data for reactions of sulfate anion radicals (SO4−) with PFCAs are needed to evaluate the residence times of PFCAs in the environment, but no kinetic data have been reported, except for the rate constant for the reaction of SO4− with trifluoroacetate (CF3C(O)O−) (k1). In this study, using the fact that PFCAs react with SO4− to form shorter chain PFCAs, we determined rates relative to k1 of the reactions of photolytically generated SO4− with two short‐chain PFCAs, pentafluoropropionate (C2F5C(O)O−; k2) and heptafluorobutyrate (C3F7C(O)O−; k3), along with conversion ratios for conversion of C2F5C(O)O− into CF3C(O)O− (α) and conversion of C3F7C(O)O− into C2F5C(O)O− (β) and CF3C(O)O− (γ) at 298 K. Values of k1, k2, or k3 might change over the course of reaction with increasing ionic strength. Nevertheless, if the values of k1/k2, k2/k3, α, β, and γ remain almost constant during the reaction, a simple equation involving relative rates, such as k1/k2, can be used to relate the concentrations of C3F7C(O)O−, C2F5C(O)O−, and CF3C(O)O−. We compared the relative rates, such as k1/k2, and the conversion ratios determined from various experimental runs with different initial conditions to check whether relative rates and conversion ratios remained almost constant during each experimental run. The values of k1/k2, k2/k3, α, β, and γ seemed to remain almost constant, which facilitated determination of k2/k1 = 0.89 ± 0.07, k3/k1 = 0.84 ± 0.08, α = 0.88 ± 0.05, β = 0.75 ± 0.05, and γ = 0.17 ± 0.02. © 2007 Wiley Periodicals, Inc. Int J Chem Kinet 39: 276–288, 2007
Assessment and demarcation of trail degradation in a nature reserve, using GIS: case of Bukit Timah Nature Reserve
Authors: Chatterjea K.
Published: March 2007

With a significant rise in popularity of nature areas, particularly in urban settings like Singapore, Nature Reserves are being increasingly opened for public recreational use. In the Bukit Timah Nature Reserve (BTNR), the only remnant primary rain forest reserve in Singapore, trail networks are being expanded to meet this growing public demand. The physical condition of the present trail networks was assessed by monitoring the changes in surface compaction, soil moisture, infiltration rates, soil organic matter content, root density, litter cover and rill development. These parameters were compared with similar data obtained from undisturbed forested slopes to analyse the degree of changes brought about by trail usage. Significant changes occurred in all measured parameters, indicating observable degradation of the trails, particularly on vulnerable slopes. These changes are due to the heavy and increased use of the forest by visitors. Penetration resistance and shear strength of the top surface layers of the trails are important indicators of trail degradation status and these have been plotted, using GIS, to demarcate trails under different levels of stress. This field monitoring provides a relevant local assessment of trail conditions. It has potential for use in decision‐making in future planning and forest management under similar site conditions. Copyright © 2007 John Wiley & Sons, Ltd.
Correlation of photodynamic activity and fluorescence signaling for free and pegylated mTHPC in mesothelioma xenografts
Authors: Tran Nam , Krueger Thorsten , Pan Youmin , Yan Hua , Cheng Cai , Altermatt Hans‐Jörg , Ballini Jean‐Pierre , Borle François , Ris Hans‐Beat , Andrejevic‐Blant Snezana
Published: March 2007

Background/Objectives

Correlation of photodynamic activity (PDT) and fluorescence signaling for free and pegylated meta‐tetrahydroxyphenylchlorin (mTHPC) in nude mice with mesothelioma xenografts.

Study Design/Materials and Methods

Twelve animals received light delivery (20 J/cm2, 150 mW/cm2, spot size 1.2 cm) on the tumor and the hind leg 3 days after sensitization with 0.15 mg/kg free mTHPC (n = 6) or equimolar‐dosed pegylated mTHPC (n = 6). Groups of three animals each were sensitized with 0.15 and 0.5 mg/kg free mTHPC or equimolar dosed pegylated mTHPC followed after 3 days by fluorescence microscopy measurements.

Results

Pegylated mTHPC resulted in a similar extent of PDT‐related tumor necrosis but in lower skin phototoxicity than free mTHPC. Both mTHPC formulations were heterogeneously distributed in the tumor and were mainly localized in perivascular areas. Pegylated mTHPC revealed a higher tumor to skin fluorescence intensity ratio than free mTHPC (P<0.001).

Conclusions

Fluorescence signaling measurement has the potential to predict the photodynamic activity for both mTHPC formulations in mesothelioma xenografts. Lasers Surg. Med. 39:237–244, 2007. © 2007 Wiley‐Liss, Inc.
PET evidence of central GABAergic changes in stiff‐person syndrome
Authors: Perani Daniela , Garibotto Valentina , Panzacchi Andrea , Moresco Rosa Maria , Ortelli Paola , Corbo Massimo , Fazio Ferruccio , Folli Franco
Published: March 2007

We measured expression of central nervous system GABA‐A receptors with 11C‐flumazenil (11C‐FMZ) and PET in two subjects with stiff person syndrome (SPS). We found reduced 11C‐FMZ binding potential (BP) in motor‐premotor cortex, and increased 11C‐FMZ BP in the cerebellar nuclei. This is the first in vivo PET evidence of central GABA‐A receptors dysfunction in SPS, possibly concurring to the motor symptoms. © 2007 Movement Disorder Society
UbiXML: programmable management of ubiquitous computing resources
Authors: Alexopoulos Dimitris , Soldatos John , Kormentzas George , Skianis Charalabos
Published: March 2007

XML technologies provide proven benefits for the configuration management of complex heterogeneous multi‐vendor networks. These benefits have been recently manifested in numerous research, industrial and standardization efforts, including the XMLNET architecture. In this paper we present UbiXML, a system for programmable management of ubiquitous computing resources. UbiXML extends the benefits of XML technologies in the broader class of ubiquitous computing environments, which are inherently complex distributed heterogeneous and multi‐vendor. In UbiXML management applications are structured as XML documents that incorporate programming constructs. Thus, UbiXML allows administrators to build sophisticated management applications with little or no programming effort. While UbiXML builds on several XMLNET concepts, it significantly augments XMLNET to handle management of sensors, perceptual components and actuating devices. Moreover, UbiXML is extensible towards additional ubiquitous computing elements. UbiXML has been exploited in implementing realistic management applications for a smart space. Copyright © 2007 John Wiley & Sons, Ltd.
A branch & cut algorithm for the windy general routing problem and special cases
Authors: Corberán Angel , Plana Isaac , Sanchis José M.
Published: March 2007

In this paper, we present an exact algorithm for the Windy General Routing Problem. This problem generalizes many important Arc Routing Problems and also has some interesting real‐life applications. The Branch & Cut method presented here is based on a cutting‐plane algorithm that identifies violated inequalities of several classes of facet‐inducing inequalities for the corresponding polyhedron. The whole procedure has been tested over different sets of instances and is capable of solving to optimality large‐size instances of several routing problems defined on undirected, mixed, and windy graphs. © 2007 Wiley Periodicals, Inc. NETWORKS, Vol. 49(4), 245–257 2007
A Power–Arnoldi algorithm for computing PageRank
Authors: Wu Gang , Wei Yimin
Published: March 2007

The PageRank algorithm plays an important role in modern search engine technology. It involves using the classical power method to compute the principle eigenvector of the Google matrix representing the web link graph. However, when the largest eigenvalue is not well separated from the second one, the power method may perform poorly. This happens when the damping factor is sufficiently close to 1. Therefore, it is worth developing new techniques that are more sophisticated than the power method. The approach presented here, called Power–Arnoldi, is based on a periodic combination of the power method with the thick restarted Arnoldi algorithm. The justification for this new approach is presented. Numerical tests illustrate the efficiency and convergence behaviour of the new algorithm. Copyright © 2007 John Wiley & Sons, Ltd.
Alkaloids of zanthoxylum budrunga wall.: NMR assignments of dihydrochelerythrine, (±)‐evodiamine and zanthobungeanine
Authors: Joshi Balawant S. , Moore Kristi M. , Pelletier S. William , Puar Mohindar S.
Published: March 2007

The root bark of Zanthoxylum budrunga has been found to contain dihydrochelerythrine, N‐norchelerythrine, (±)‐evodiamine, zanthobungeanine and lupeol. NMR spectral studies (1H, 13C, 1H homonuclear COSY, HETCOR, DIFNOE and selective INEPT) carried out on these alkaloids have enabled the accurate chemical shift assignments for dihydrochelerythrine, (±)‐evodiamine and zanthobungeanine to be established.
A new method for alkaloid extraction from Chelidonium majus L.
Authors: Bugatti C. , Colombo M. L. , Tomé F.
Published: March 2007

The increasing interest in Chelidonium majus L. and its various metabolites (i.e., the isoquinoline alkaloids, sanguinarine, chelerythrine, chelidonine and berberine) has given rise to a need for a rapid and reproducible method for the standardization and evaluation of fresh C. majus extracts. Both quaternary and tertiary alkaloids can be isolated from vegetable material by means of ion pair extraction and the recovery of these compounds was found to be consistently greater than 90%.
High performance liquid chromatographic determination of alkaloids from Vinca minor L.
Authors: Proksa B. , Grossmann E.
Published: March 2007

Fourteen alkaloids from Vinca minor L. were separated and their concentration determined by high performance liquid chromatography using Separon SGX C18 with a mobile phase of methanol:water (0.02 mol/L NH4Cl, pH 8.2 adjusted with Et3N). The major alkaloids of the leaves were vincamine (0.13%), 1,2‐dehydroaspidospermidine (0.06%) and vincaminoreine (0.028%). The dominant alkaloid of the root was 1,2‐dehydroaspidospermidine (0.28%). The bisindole alkaloid vincarubine was found only in the leaves (0.007%).
Laboratory selection of Artemisia annua L. for high artemisinin yielding types
Authors: Pras Niesko , Visser Jan F. , Batterman Sieb , Woerdenbag Herman J. , Malingré Theo M. , Lugt Charles B.
Published: March 2007

Artemisia annua L. (Asteraceae) contains artemisinin, a sesquiterpene lactone with promising antimalarial properties. At present the artemisinin content in plants grown in the open in the Netherlands is too low for industrial purposes. We describe a new method for laboratory selection to identify high yielding individual plants for the purpose of seed production and subsequent efficient cropping. During the procedure thin layer chromatography and high performance liquid chromatography were used as methods of analysis for artemisinin. Selected 11‐week‐old plantlets were transferred from the laboratory into the open in the summer of 1989. We have observed that plants which are high yielding in the laboratory continue to be so in the field. The A. annua crop which had been sown‐out directly had on average a 3–4‐fold lower artemisinin content.
Synthesis of uridinediphospho‐[U‐14C]‐D‐galacturonic acid by enzyme particulate fractions and purification via high performance liquid chromatography
Authors: Mitcham Elizabeth J. , Gross Kenneth C. , Wasserman Bruce P.
Published: March 2007

Uridinediphospho‐[U‐14C]‐D‐galacturonic acid (UDP‐[U‐14C]‐galacturonic acid) can be produced using UDP‐D‐glucuronic acid‐4′‐epimerase in radish root or mung bean hypocotyl enzyme particulate fractions. Epimerase activity was stable for several months at –70°C. Mung bean extracts had the highest activity per ng of protein. Enzymatic modification of UDP‐[U‐14C]‐galacturonic acid and formation of 14C‐breakdown products was reduced by short incubation times (<5 min). Using high performance liquid chromatography on an aminopropyl column, UDP‐[U‐14C]‐galacturonic acid can be separated and collected without contamination by other products for use as a radiolabelled substrate for assay of galacturonan synthase with a yield of 14%.
An homogeneous radioimmunoassay for abscisic acid using a scintillation proximity assay technique
Authors: Whitford P. N. , Croker S. J.
Published: March 2007

An homogeneous radioimmunoassay (RIA) for the plant growth regulator abscisic acid (ABA) has been developed by modifying an established heterogeneous assay. The introduction of a scintillation proximity reagent has enabled the production of a one‐step RIA in which radioactivity associated with antibody‐bound ABA can be counted in the presence of the unbound radiolabelled ABA and without the addition of a liquid scintillation cocktail. The assay has been validated by comparing the results with those obtained by combined gas chromatography/mass spectrometry and the precision of each method determined. The homogeneous RIA has a working range of 0.165–13.2 ng ABA and has been used to determine ABA concentration in extracts of leaves of tomato, Lycopersicon esculentum Mill. cv. Ailsa Craig (wild type) and three wilty mutants, notabilis, flacca and sitiens.
The isolation of eleutherococcus senticosus constituents by centrifugal partition chromatography and their quantitative determination by high performance liquid chromatography
Authors: Slacanin Ivan , Marston Andrew , Hostettmann Kurt , Guédon Didier , Abbe Philippe
Published: March 2007

An investigation of Eleutherococcus senticosus roots, using centrifugal partition chromatography as a key intermediate separation step, has led to the straightforward isolation of eight constituents. Four of these, sinapaldehyde glucoside, coniferaldehyde glucoside, coniferin and 1,5‐di‐O‐caffeoylquinic acid, have been described for the first time in this plant. The quantitative analysis of different E. senticosus samples has been performed by high performance liquid chromatography using eleutherosides B and E as external standards.
Flow cytometric analysis of nuclear DNA content in higher plants
Authors: Doležel J.
Published: March 2007

Methods of flow cytometric analysis of nuclear DNA content were originally developed for human cells. They are based on the use of DNA‐specific fluorochromes and on the analysis of the relative fluorescence intensity of stained nuclei. During the last decade this methodology has been adapted to the analysis of plant cells. This article reviews the current status of this rapidly developing field. Special attention is given to preparative techniques, methods of instrument calibration and standardization, and interpretation of data. Multiparameter methods which supplement DNA content analysis are also reviewed.
Chiral compounds of essential oils. VIII: Stereodifferentiation of linalool using multidimensional gas chromatography
Authors: Schubert V. , Mosandl A.
Published: March 2007

This paper reports on the chiral evaluation of linalool as an additional criterion of authenticity of lavender oils, using enantioselective multidimensional gas chromatography with a column combination of Superox and heptakis(2,3,6‐tri‐O‐ethyl)‐β‐cyclodextrin in OV‐1701‐vi. This method is extended to some other valuable spice oils‐investigations on the enantiomeric distribution of their linalool content are discussed in terms of quality control of essential oil.
Chirospecific analysis of 2‐alkyl‐branched alcohols, acids, and esters: Chirality evaluation of 2‐methylbutanoates from apples and pineapples
Authors: Rettinger Klaus , Karl Volker , Schmarr Hans‐Georg , Dettmar Frank , Hener Uwe , Mosandl Armin
Published: March 2007

Using perethylated β‐cyclodextrin as a chiral stationary phase the alcohols 2‐methyl‐1‐butanol (1), ‐pentanol (2), ‐hexanol (3) and 2‐ethyl‐1‐hexanol (4), the free carboxylic acids 2‐methyl‐butanoic (5), ‐pentanoic (6), ‐hexanoic (7) and 2‐ethylhexanoic (8) as well as the esters methyl and ethyl 2‐methylbutanote (9, 10) are resolved into their mirror images without derivatization. Chiral capillary gas chromatography was used to determine the enantiomeric distribution of the 2‐methylbutanoates 9 and 10 in pineapples and 15 apple varieties, using extractive and dynamic headspace methods, respectively.
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

Protein 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

A 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

Three 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

The 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

A 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

This 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

Gibberellin 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

A 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

The 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

Losses 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

A 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

A 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

A 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

A 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

An 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

The 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

Ion‐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

The 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

The 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

A 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

A 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

A 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

Different 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

Coenzyme 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.