Production of an egg yolk antibody against Parietaria judaica 2 allergen

Specific antibodies are essential tools for studying proteins as well as for diagnostic research in biomedicine. The egg yolk of immunized chicken is an inexpensive source of high-quality polyclonal antibodies. The 12-kDa Parietaria judaica 2 allergen was expressed as a fusion protein and was used to immunize Leghorn chickens. In this paper, we show, using 2-dimensional gel electrophoresis and immunoblotting, that chicken antibodies raised against a recombinant allergen can be used to recognize similar proteins from a pollen raw extract. Allergen identity was confirmed by nanoLC-nanospray-tandem mass spectrometry analysis. Our data demonstrate for the first time that a synergistic combination of molecular biology, 2-dimensional PAGE, and use of nonmammalian antibodies represents a powerful tool for reliable identification of allergens.

Impedance Spectroscopy of Water Solutions: The Role of Ions at the Liquid−Electrode Interface

We discuss the influence of the ions dissolved in a liquid on the impedance spectroscopy of a cell. Our analysis is performed in the small-voltage regime, where the actual bulk density of ions is only slightly perturbed by the external electric field. In this framework, we show that the presence of the ions can be taken into account by a surface density of charge. The agreement between the theoretical prediction, on the basis of the assumption that the ionic mobility is frequency independent, and the experimental data for the real and imaginary parts of the impedance is fairly good for frequencies larger than 100 Hz. In the low-frequency range, the agreement of the theory with the experiment is rather poor. In this region, the experimental data can be successfully fitted by introducing the impedance of the metal-electrolyte interface, which is accurately represented by Zi = w(i omega)(-nu), where w and nu are two constants, with 0 < nu < 1. From the analysis of the experimental data, we determine w and nu. The theoretical predictions of our model are in good agreement with the experimental data in the investigated frequency range.

Covalent binding of 15-deoxy-delta12,14-prostaglandin J2 to PPARgamma

Since 15-deoxy-delta(12,14)-prostaglandin J(2) (15dPGJ(2)) has been identified as an endogenous ligand of PPARgamma thus inducing adipogenesis, it has been reported to play active parts in numerous cellular regulatory mechanisms. As 15dPGJ(2) has been shown to covalently bind several peptides and proteins, we investigated whether it also covalently binds PPARgamma. We first observed that after incubation of 15dPGJ(2) with recombinant PPARgamma, the quantity of free 15dPGJ(2) measured was always lower than the initial amount. We then measured the ability of the labeled agonist rosiglitazone to displace the complex PPARgamma(2)/15dPGJ(2) obtained after pre-incubation. We observed that the binding of rosiglitazone was dependent on the initial concentration of 15dPGJ(2). Finally using MALDI-TOF mass spectrometry analysis, after trypsinolysis of an incubate of the PPARgamma(2) ligand binding domain (GST-LBD) with 15dPGJ2, we found a fragment (m/z = 1314.699) corresponding to the addition of 15dPGJ(2) (m/z = 316.203) to the GST-LBD peptide (m/z = 998.481). All these observations demonstrate the existence of a covalent binding of 15dPGJ(2) to PPARgamma, which opens up new perspectives to study the molecular basis for selective activities of PPARs.

Anomalous intensity dependence of optical reorientation in azo-dye-doped nematic liquid crystals

The intensity dependence of optical nonlinearity in a nematic liquid crystal doped with an azo-dye is investigated. The reorientational part of the nonlinearity changes from self-defocusing to self-focusing character while the intensity passes through the saturation value of trans-cis photoisomerization. This observation, in accordance with previous models, indicates that the optical torque generated by the trans-isomers is of opposite sign than the torque generated by the cis-isomers. At very low intensities a further reorientational nonlinearity was found, which is attributed to light-induced orientational redistribution of adsorbed molecules at the surface.

Analysis of aromatic sulfur compounds in gas oils using GC with sulfur chemiluminescence detection and high-resolution MS

The analysis of alkylbenzothiophenes (alkyl-BT) and alkyl-dibenzothiophenes (alkyl-DBT) in light cycle oil (LCO) and straight run (SR) gas oils is described. A detailed identification and quantitative analysis of alkyl-BT and alkyl-DBT present in LCO gas oils was carried out using GC-SCD. For the SR gas oils, the simultaneous presence of thiophenic and nonthiophenic compounds does not allow for a selective analysis of thiophenic compounds by GC-SCD. A new method using gas chromatography coupled with high-resolution mass spectrometry (GC-HRMS) is proposed to selectively detect and quantify the alkyl-BT and alkyl-DBT in SR gas oils. The development of the method and comparison of results between GC-SCD and GC-HRMS are presented.

Environmental quality and sustainability in the province of Reggio Emilia (Italy): using multi-criteria analysis to assess and compare municipal performance

Sustainability has become an increasingly significant issue, although practical implementation remains difficult. In Italy, promoting sustainability is particularly problematic at the provincial and municipal level, where the lack of resources and expertise, and the effects of uncoordinated policies make it difficult to achieve minimum requirements to make sustainable policies operational. One essential requirement is knowledge of baseline environmental conditions in each municipality. In the province of Reggio Emilia (Northern Italy) Legambiente, an environmental association, launched an initiative called 'Ecopaese' aimed at gathering data on environmental conditions and stimulating local administrations to implement sustainable policies. To this end, the state of the environment in the 45 municipalities within the province has been monitored using 25 indicators. Their values have been used to rank the municipalities by multiple criteria analysis (MCA). The results of this comparative approach provide information about the level of sustainability attained in the province as a whole as well as in the single municipalities. It is hoped that it will provide the basis for direct action plans at the provincial level by identifying areas for remedial action, as recommended by Agenda 21, the declaration adopted by many countries attending the Rio Summit in 1992.

Formation of cryptophanes from their precursors as viewed by liquid secondary ion mass spectrometry

The formation of cryptophane-A (C1) and the deuterated cryptophanes C2-C6 from their respective precursors P1-P6 in a mass spectrometer ion-source was evidenced by liquid secondary ion mass spectrometry (LSIMS). Mass-analyzed ion kinetic energy experiments performed on the precursor molecular ions suggested that cryptophane formation occurred mainly in the liquid-matrix before desorption rather than in the gas phase. In addition, we observed that the presence of cations, such as lithium or sodium ions, inhibited the formation of the cryptophane molecular ions. In the light of these results we used the LSIMS technique to investigate the formation of the new cryptophanes C7-C13. All the data collected support the idea that a direct comparison can be made between these experimental findings and chemistry in solution.

Bloch wave approach to the optics of crystals

The Bloch wave method is used to find the effective permittivity tensor epsilon of periodic liquid crystals and artificial structures whose period p is short with respect to the light wavelength lambda and whose optical properties are defined by a permittivity field epsilon(r). The main role of the multiple scattering within the periodic medium is evidenced, and very general expressions of epsilon, based on expansions in ascending powers of the ratio p/lambda and of the light wave vector k, are found. Such expansions allow to discuss the general properties of epsilon, to clarify the role of the spatial dispersions, i.e., to separate the part of epsilon explicitly depending on k from its k-independent part, and to find some interesting properties of crystals that are (i) periodic in only one direction, or (ii) locally isotropic. Finally, the limits of validity of the macroscopic model are discussed. Within these limits only a few terms of the power expansions are required, and their expressions are explicitly given. The obtained results are also useful to better understand the macroscopic optical properties of solid crystals.

Structural determination of zinc dithiophosphates in lubricating oils by gas chromatography-mass spectrometry with electron impact and electron-capture negative ion chemical ionization

Pentafluorobenzyl ester derivatives were used to identify zinc dialkyldithiophosphates and diaryldithiophosphates antiwear engine oil additives by GC-electron impact ionization (EI) MS and GC-electron-capture negative ion chemical ionization (ECNCI) MS analysis. GC-EI-MS of the dialkyldithiophosphate-pentafluorobenzyl derivatives afforded characteristic fragment ions corresponding to the cleavage of one and two alkyl radicals. In most cases, information was only obtained on one alkyl chain. Additional and complete information was obtained with retention time indices using synthetic derivatives and with GC-ECNCI-MS analysis. ECNCI afforded characteristic dithiophosphate anions which allowed the determination of the total number of carbon atoms in the alkyl radicals. The diastereoisomer mixtures of 2-hydroxy-sec.-alkyl radicals were completely separated on GC analysis.

Detection of exogenous intake of natural corticosteroids by gas chromatography/combustion/isotope ratio mass spectrometry: application to misuse in sport

A detailed procedure for the analysis of exogenous hydrocortisone and cortisone in urine by gas chromatography/combustion/isotope ratio mass spectrometry (GC/C/IRMS) is proposed. As urinary levels of hydrocortisone are rather low for GC/C/IRMS analysis, the focus is on the main corticosteroid metabolites, tetrahydrocortisone (THE) and tetrahydrocortisol (THF). Following different solid phase extraction purifications, THE and THF are oxidized to 5beta-androstanetrione before analysis by GC/C/IRMS. Significant differences in delta(13)C per thousand values of synthetic natural corticosteroids and endogenous human corticosteroids have been observed. Therefore, a positive criterion, to detect exogenous administration of synthetic corticosteroids in anti-doping control, is proposed.

Two new alpha chain variants: Hb Boghé [alpha58(E7)His-->Gln, alpha2], a variant on the distal histidine, and Hb CHarolles [alpha103(G10)His-Tyr, alpha1]

The present paper reports two new alpha-globin chain variants: Hb Boghé [alpha58(E7)His-->Gln, alpha2] and Hb Charolles [alpha103(G10)His-->Tyr, alpha1]. Hb Boghé was found in a 12-month-old girl who was treated for malignant histiocytosis at 9 months of age and received a bone marrow transplant from her sister. Hb Boghé was undetectable by isoelectrofocusing and high performance liquid chromatography of hemoglobins. It was only revealed by polyacrylamide gel electrophoresis of globin chains in the presence of urea-Triton X-100 and accounted for 10% of the total hemoglobin. Hb Charolles was detected in a 46-year-old patient who presented with microcytosis and hypochromia. It was easily detected by isoelectrofocusing and high performance liquid chromatography. Hb Charolles accounted for 11% of the total hemoglobin. Characterization of the two hemoglobin variants was achieved by DNA and restriction enzyme analyses. Oxygen equilibrium curves measured on whole blood with Hb Boghé were normal. DNA sequencing revealed the association of Hb Charolles with a common mutation of the alpha2 polyadenylation site: AATAAA-->AATAAG.

Screening urine for exogenous testosterone by isotope ratio mass spectrometric analysis of one pregnanediol and two androstanediols

We propose a new screening method for testosterone (T) doping in sport. The current method for detecting T administration is based on finding a T to epitestosterone ratio (T/E) in urine that exceeds six. The difficulties with T/E are that T administration does not always result in a T/E>6 and that a rare individual will have T/E>6 in the absence of T administration. Our previous studies reveal that carbon isotope ratio helps to determine the origin of the urinary T because the values for T and its metabolites decrease after the administration of exogenous T. In this study, we present a rapid and efficient screening sample preparation method based on three successive liquid-solid extractions, deconjugation with E. coli beta-glucuronidase after the first extraction, acetylation after the second extraction, and a final extraction of the acetates. The 13C/12C of two T metabolites (5beta-androstane-3alpha,17beta-diol and 5alpha-androstane-3alpha,17beta-diol) and one pregnanediol as endogenous reference (5beta-pregnane-3alpha,20alpha-diol) was measured by gas chromatography-combustion-isotope ratio mass spectrometry (GC-C-IRMS) on 10 ml of urine collected from 10 healthy men before and after T administration. Following T administration, the 13 C/12C of 5beta-androstane-3alpha,17beta-diol diacetate and 5alpha-androstane-3alpha,17beta-diol diacetate declined significantly from -26.2 per thousand to -30.8 per thousand and from -25.2 per thousand to -29.9 per thousand, respectively and the 13C/12C of 5beta-pregnane-3alpha,20alpha-diol diacetate was unchanged. In addition, the ratio of androstanediols to pregnanediol increased in the post-T urines.

Saponins from the stem bark of Filicium decipiens

Four new saponins have been isolated from the stem bark of Filicium decipiens and identified as 3-O-{beta-D-glucopyranosyl(1-->2)-beta- D-glucopyranosyl}-28-O-{[alpha-L-arabinopyranosyl(1-->2)-beta- D-xylopyranosyl (1-->6)]. [4-O-angeloyloxy-alpha-L-arabinopyranosyl(1-->2)-alpha-L- rhamnopyranosyl(1-->2)]}-beta-D-glucopyranosyl gypsogenic acid, 3-O-{beta-D-glucopyranosyl(1-->2)-beta-D- glucopyranosyl}-28-O-{[alpha-L-arabinopyranosyl(1-->2)- beta-D-xylopyranosyl(1-->6)] [4-O-angeloyloxy-alpha-L- arabinopyranosyl(1-->2)-alpha-L-rhamnopyranosyl(1-->2)]}-beta-D- glucopyranosyl medicagenic acid, 3-O-{beta-D-glucopyranosyl(1-->2)-beta-D- glucopyranosyl}-28-O-{[alpha-L-arabinopyranosyl(1-->2)] [beta-D-xylopyranosyl(1-->4)]alpha-L-rhamnopyranosyl(1-->2)-4-O-[3'- hydroxy-2'-methyl-butyroyloxy)-3-hydroxy-2-methyl-butyroyloxy++ +]-beta-D- fucopyranosyl} medicagenic acid and 3-O-beta-D-glucopyranosyl-28-O- {[alpha-L-arabinopyranosyl(1-->2)] [beta-D-xylopyranosyl(1-->4)] alpha-L-rhamnopyranosyl(1-->2)-4- O-[(3'-hydroxy-2'-methyl-butyroyloxy)-3-hydroxy-2-methyl-butyro yloxy]-beta- D-fucopyranosyl} zanhic acid. These structures were elucidated by analysis of 2D-NMR spectra and of electrospray ionization mass spectra.

Oxidative decarboxylation of benzoic acid by peroxyl radicals

A chemical model based on the thermal decomposition of AAPH (2,2'-azobis(2-amidinopropane) dihydrochloride is used for the production of peroxyl radicals. Peroxyl radicals induces the decarboxylation of [7-13C]benzoic acid and the production of 13CO2, which is measured by gas chromatography-isotope ratio mass spectrometry (GC-IRMS). The decarboxylation depends on temperature, AAPH, and benzoic acid concentrations. The decarboxylation also depends on the presence of oxygen. Electron spin resonance studies are performed to confirm the presence of peroxyl radicals under oxygen and of carbon-centered radicals in the absence of oxygen. Decarboxylation rates are measured in the presence of various antioxidants: ascorbate, dimethylsulfoxide, mannitol, and uric acid. It turns out that the decarboxylation is inhibited by each of these antioxidants. The ratio of decarboxylation rates, with and without the antioxidant, varies linearly with the antioxidant concentration. HPLC and GC-MS analyses of reaction products between benzoic acid and AAPH-derived radicals do not detect the presence of radical substitution products on the aromatic ring or the products derived from benzoic acid. There is no doubt that GC-IRMS is a powerful technique to investigate the effects of peroxyl radicals on benzoic acid. In addition, it is possible to follow the degradation of 13C-labeled chemical targets exposed to peroxyl radicals through the production of 13CO2.

Flavonoid content of Asphodelus ramosus (Liliaceae)

In the course of a preliminary chemosystematic study of Asphodelus species, six flavonoids were first isolated and identified from A. ramosus subsp. ramosus var. ramosus. Only flavone structures were found. Two of them are rare C-glycoside structures and were observed only in the samples from one of the two geographic areas. So, flavonoids might be used as markers in the study of the Asphodelus genus organization. Key words: Asphodelus ramosus, Liliaceae, flavonoids, C-glycosylflavones, chemosystematics.

Detection of exogenous hydrocortisone in horse urine by gas chromatography-combustion-carbon isotope ratio mass spectrometry

A gas chromatography-combustion-isotope ratio mass spectrometry method for confirmation of hydrocortisone abuse in horseracing and equine sports is proposed. Urinary hydrocortisone was converted to a bismethylenedioxy derivative which presents good gas chromatographic properties and brings an extra carbon contribution of only two carbon atoms. Synthetic hydrocortisone has a different 13C abundance from that of natural urinary horse hydrocortisone and the difference is significant, therefore exogenous and endogenous hydrocortisone can be distinguished.

[Study of plasma acylcarnitines using tandem mass spectrometry. Application to the diagnosis of metabolism hereditary diseases]

BACKGROUND

L-carnitine is known to transport long chain fatty acids through the mitochondrial membrane but also to export accumulated acyl-CoA's as acylcarnitine esters. Acylcarnitine identification in body fluids allows the diagnosis of mitochondrial inborn errors especially fatty oxidation defects. Tandem mass spectrometry represents a new method for isolation and identification of acylcarnitines in plasma or in blood spotted onto filter paper (Guthrie cards).

MATERIAL AND METHODS

In order to validate our method, we studied 30 plasmas from children affected with 15 different inborn errors of metabolism and five amniotic fluids from fetuses affected with several organic acidurias. Fourty-six samples from children at risk for mitochondrial fatty oxidation disorders have been analyzed. We developed a method of tandem mass spectrometry with liquid secondary ion mass spectrometry using deuterated acylcarnitines as internal standards.

RESULTS

This method is very sensitive (detection limit = 2 microM). In all affected patients specific acylcarnitine signals corresponding to the metabolic block were constantly found. This confirms the diagnosis and validates the method. Among the 46 at risk children, four defects of long chain fatty acid oxidation were identified.

CONCLUSION

This new method is of great interest especially for the long chain fatty acid oxidation defects. These defects are very difficult to diagnose with classical methods as urinary organic acid profiling. A small amount of plasma (100 microL) or blood spotted onto paper is required. The acylcarnitine profile allows a rapid diagnosis if a dedicated apparatus is available.

Isolation and characterization of inositol sphingophospholipids from Phytophthora parasitica Dastur

Several inositol sphingophospholipids (ISPL) were isolated from mycelia of Phytophthora parasitica Dastur, a phytopathogenic fungus of carnation. The ISPL structures were determined by fast atom bombardment. All ISPL consisted of ceramides linked to inositol phosphate. We investigated the effect of growth conditions on the ISPL produced in four different media that are commonly used for fungal cultures. We showed that P. parasitica Dastur synthesized four major classes of compounds with molecular weights of M(r) = 751, 807, 835, and 849 containing the 16:1 base and the 16:0 or 20:0 or 22:0 or 22h:1 N-acyl group. The relative abundance of the different ISPL is dependent on growth conditions.

Detection of testosterone misuse: comparison of two chromatographic sample preparation methods for gas chromatographic-combustion/isotope ratio mass spectrometric analysis

Two chromatographic methods, reversed-phase liquid chromatography (LC) and immunoaffinity chromatography (IAC), were compared in the preparation of purified testosterone extracts suitable for gas chromatography-combustion/isotope ratio mass spectrometry (GC-C-IRMS) analysis. We have shown previously that GC-C-IRMS is a promising means of detection of testosterone misuse in sport. The two clean-up procedures afford sufficient recovery and adequate purity of testosterone. LC presents several advantages over IAC: access to other urinary steroids, longer column life, no need for special equipment and no antibody preparation. For IAC, the antibodies to testosterone must be selected with care for high affinity and low cross-reactivity. Nevertheless, IAC is of some interest in our experiments, the recovery is slightly better for low concentrations of urinary testosterone and IAC does not induce isotopic discrimination even in overloading experiments. This is the first report on sample preparation by IAC prior to GC-C-IRMS and carbon isotope ratio values for urinary epitestosterone. The carbon isotope ratio test can identify users' urines missed by the testosterone to epitestosterone ratio (T/E > 6) test.

Urinary testosterone (T) to epitestosterone (E) ratios by GC/MS. I. Initial comparison of uncorrected T/E in six international laboratories

Six laboratories in six countries collaborated to investigate the analytical method for estimating the testosterone to epitestosterone ratio (T/E) in urine by gas chromatography/mass spectrometry in the context of detecting the application of T as a doping agent in sport. The protocol specified many but not all details of reagents and instrument conditions. The design included the distribution and analysis of four urines with different T/E values, three replicates per value, and one standard. The ranges of mean T/E values for the four urines estimated by peak area (PA) were 0.32-0.42, 0.72-0.94, 0.91-1.14 and 3.19-5.48. The analyses of variance for these data and for the peak height (PH) data were significant for the laboratory factor (p < 0.0001). In addition there was a significant interaction between the urine factor and the laboratory factor which indicates the complexity of the analysis. T/E calculated using PA was not significantly different from that using PH. For within-laboratory precision all values for PH and PA were < 8.3%, and for between-laboratory precision all values were < 11.7% except for one (20.1%). The data represent a baseline for future experiments designed to elucidate the sources of within-and between-laboratory variance, and to harmonize estimates of T/E.

Improved method of detection of testosterone abuse by gas chromatography/combustion/isotope ratio mass spectrometry analysis of urinary steroids

The current approach to detection of doping with testosterone is based on measuring the testosterone to epitestosterone ratio (T/E) in urine by gas chromatography/mass spectrometry. The median T/E for healthy males who have not used T is about 1.0. In a single urine, a T/E lower than six leads to a negative report even though it does not exclude T administration. A value greater than six indicates possible T administration or a naturally elevated ratio. It has been shown previously that the carbon isotope ratio of urinary T changes after T administration. In this study a potential confirmation method for T abuse was optimized. Gas chromatography/combustion/carbon isotope ratio mass spectrometry (GC/C/IRMS) was used to analyze two T precursors (cholesterol and 5-androsten-3 beta, 17 beta-diol) and two T metabolites (5 alpha- and 5 beta-androstane-3 alpha, 17 beta-diol) in addition to T itself in each of 25 blind urines collected from eight healthy men before, during or after T administration. The carbon isotope ratios of T and the metabolites were lower after T administration. The relationships among the variables were studied using multivariate analysis and beginning with principal components analysis; cluster analysis revealed that the data are composed of two clusters, and classified the samples obtained after T administration in one cluster and the remainder in the other; discriminant analysis correctly identified T users. The measurement of carbon isotope ratios of urinary androgens is comparable to the T/E > 6 test and continues to show promise for resolving cases where doping with T is suspected.

Saponins from three species of Mimusops

Six saponins were isolated from the seed kernel of Mimusops elengi, M. hexandra and M. manilkara. Their structures were determined using a combination of 1H NMR, 13C NMR and mass spectroscopy. Three of them are new compounds: 3-O-(beta-D-glucuronopyranosyl) 28-O-(alpha-L-rhamnopyranosyl (1-->3) beta-D-xylopyranosyl(1-->4) [alpha-L-rhamnopyranosyl(1-->3)] alpha-L-rhamnopyranosyl(1-->2) alpha-L-arabinopyranosyl) protobassic acid, 3-O-(beta-D-glucuronopyranosly) 28-O-(alpha-L-rhamnopyranosyl(1-->3) beta-D-xylopyranosyl(1-->4) alpha-L-rhamnopyranosyl(1-->2) alpha-L-arabinopyranosyl) 16-alpha-hydroxyprotobassic acid and 3-O-(beta-D-glucopyranosyl(1-->3) beta-D-glucopyranosyl) 28-O-(alpha-L-rhamnopyranosyl(1-->3) beta-D-xylopyranosyl(1-->4) alpha-L-rhamnopyranosyl(1-->2) alpha-L-arabinopyranosyl) protobassic acid.

Occurrence and biological effects of cholesteryl sulfate on blood platelets

Although the exact function of cholesteryl sulfate (CS) is unknown, it is present in low concentration in lipoproteins, in red blood cells and spermatozoa. In the present study, we investigated whether CS is present in blood platelets and its possible biological involvement in platelet function. Extensively washed platelets were prepared from rat and human blood. After lipid extraction and thin layer chromatography (TLC) on silica gel, a compound with the same mobility as authentic CS was isolated and identified by two different methods: (1) without hydrolysis, negative ion fast atom bombardment combined with tandem mass spectrometry (MS/MS); (2) after acidic hydrolysis, identification of cholesterol (Chol) by TLC and gas chromatography-MS. CS concentrations measured using beta-sitosteryl sulfate as internal standard in normal rat or human platelets were in the range of 164-512 pmol/10(9) platelets. This represented less than 1% of cell Chol. Biological effects of CS on platelet function were studied in vitro. CS incubated with rat platelets either as methanol solution or as albumin-bound complex potentiated the ADP- or thrombin-induced aggregation and serotonin secretion. The results of platelet sterol analysis indicated that CS was incorporated into platelet membrane and did not significantly change the platelet cholesterol composition. The potentiating effect of CS on platelet-induced aggregation and secretion was not obtained with cholesterol, cholesteryl acetate or estrone. In contrast, an inhibitory effect of estrone sulfate was observed. These results indicate that both the sulfate group and the cholesterol moiety are involved in the pro-aggregant property of CS. In addition, platelet mediators seem to be implicated in the mechanism since the thrombin-induced production of thromboxane B2, the stable end-product of arachidonic acid metabolism, was also enhanced in the presence of CS. These results suggest a new role for CS which may be involved in the modulation of platelet function.

Purification from human plasma of a tetrapeptide that potentiates insulin-like growth factor-I activity in chick embryo cartilage

Human plasma has been shown to contain a low molecular weight factor that potentiates human IGF-I stimulation of glycosaminoglycan synthesis in chick embryo cartilage. The peptide was purified and characterized by Edman degradation and electrospray mass spectrometry. The primary structure determined was: Trp-Gly-His-Glu. A homologous synthetic peptide similarly promoted matrix biosynthesis in cartilage exposed to IGF-I.

Formation of 8-nitroguanine by the reaction of guanine with peroxynitrite in vitro

Nitric oxide and superoxide anion, both formed in inflamed tissues, react rapidly to form the peroxynitrite anion (ONOO-), a strong oxidant which can initiate reactions characteristic of hydroxyl radical (HO.), nitronium ion (NO2+) and nitrogen dioxide radical (NO2.). Peroxynitrite, therefore, may cause DNA or tissue damage, contributing to the multistage carcinogenesis process. We have studied reactions of various bases, nucleosides or deoxynucleosides with peroxynitrite in vitro. Guanine reacted rapidly with peroxynitrite under physiological conditions and formed several substances, two of which were yellow, a characteristic of nitro and nitroso compounds. On the basis of chromatographic and spectral evidence we identified the major compound (which accounts for approximately 80% of all compounds formed) as 8-nitroguanine. Its formation was maximal at approximately pH 8 and increased dose-dependently with peroxynitrite concentration, but was not dependent on guanine concentration. The presence of ferric ions, which has been shown to catalyse nitration of tyrosine, did not affect nitration of guanine. 8-Nitroguanine could act as a specific marker for DNA damage induced by peroxynitrite in inflamed tissues.

Sequencing of hydrophobic peptides as lithiated adducts using liquid secondary-ion mass spectrometry without tandem mass spectrometry

Lithium cationized hydrophobic peptides in the molecular weight range 1900-2650 Da have been studied by liquid secondary-ion mass spectrometry. The mass spectra exhibit characteristic lithiated sequence ions. N-terminal [a(n)+Li-H]+ and [dn+Li-H]+ ions together with limited C-terminal [ypro+Li+H]+ ions lead to an easy sequencing of the peptides studied, without the need for tandem mass spectrometry.

Gas chromatography/combustion/isotope-ratio mass spectrometry analysis of urinary steroids to detect misuse of testosterone in sport

We propose a new confirmatory method for testosterone doping in sport. The present method in use, based on measuring the testosterone/epitestosterone (T/E) ratio in urine, may miss suspicious cases, or lead to reporting cases in which the high ratio is natural. Synthetic testosterone has a 13C abundance different from that of endogenous human testosterone. The connection of a gas chromatograph to an isotope-ratio mass spectrometer via a combustion interface allows the measurement of the corresponding characteristic value (delta /1000) for testosterone, its precursors, and its metabolites. To detect exogenous administration of testosterone, 30-40 mL of urine is sufficient.

Approach to the analysis of diuretics and masking agents by high-performance liquid chromatography-mass spectrometry in doping control

The application of thermospray and plasmaspray high-performance liquid chromatography-mass spectrometry to the analysis of diuretics and probenecid has been investigated. The latter method gave better ionization efficiency than the former, and its response was optimized by altering the solvent composition: best results were obtained with water-methanol-acetonitrile-trifluoroacetic acid. Using different proportions of these solvents, three isocratic systems were developed to separate the compounds under study. The principal characteristic of plasmaspray positive-ion mass spectra was a protonated molecular ion and very little fragmentation was evident. In the negative ionization mode, the plasmaspray method gave mass spectra showing more fragmentation, which resulted in additional structural information. The ability of trifluoroacetic acid to form negative cluster ions precluded its use as a mobile phase component. The minimum detectable amounts determined by the analysis in the positive-ion mode was compound-dependent, but generally ca. 10-150 ng. In many cases the compounds could be detected in urine extracts.

[Structure of chrysantellin B, a new saponin isolated from Chrysanthellum procumbens Rich (author's transl)]

A new saponin, chrysantellin B, has been found in a tropical plant Chrysanthellum procumbens Rich as a minor companion of chrysantellin A which was previously studied. The structure of chrysantellin B was determined by mass spectrometry, proton and 13C nuclear-magnetic resonance. The aglycone part is a triterpene: 3 beta, 16 alpha, 23-trihydroxy-olean-12-en-28-oic acid or caulophyllogenin. Carbohydrate components are D-glucose, D-oxylose and L-rhamnose in a molar ratio 1:2:2. The structure of chrysantellin B was established as 3-O-beta-D-glucopyranosyl[L-rhamnopyranosyl-(alpha 1 leads to 3)-D-xylopyranosyl-(beta 1 leads to 4)-L-rhamnopyranosyl-(alpha 1 leads to 2)-D-xylopyranosyl-(beta 1 leads to 28)]caulophyllogenin.

Structure of a new saponin: chrysantellin A from Chrysanthellum procumbens Rich

A new saponin has been isolated from a tropical plant Chrysantellum procumbens Rich. which is thought to be useful in the therapy of digestive troubles. The structure of this saponin was determined by chemical methods, nuclear magnetic resonance and mass spectrometry. The aglycone moiety is a triterpene, echinocystic acid; D-glucose, D-xylose and L-rhamnose are carbohydrate components. The structure of saponin was established as 3-O-beta-D-glucopyranosyl [L-rhamnopyranosyl-(alpha 1 leads to 3)-D-xylopyranosyl-)beta 1 leads to 4)-L-rhamnopyranosyl-(alpha 1 leads to 2)-D-xylopyranosyl]-(alpha 1 leads to 28)-echinocystyl. The name, chrysantellin A, is proposed for this new saponin.