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Plant injuries activate signal transduction cascades mediated by the plant hormones, which lead to enhanced expression of defence related genes and/or to changes in the emission of volatile organic compounds that can act as semiochemicals. In this research we demostrated that infection with the biotrophic pathogen Golovinomyces cichoracearum (DC.) V.P. Heluta (ex Erysiphe cichoracearum DC.), the causal agent of powdery mildew, led in the susceptible host Nicotiana tabacum L. cv Havana 425 to an increased emission of volatile compounds including Methyl-jasmonate (MeJA), (E)-2-hexenal and (E)-β-ocimene. Furthermore we investigated the role of these volatiles in the plant-pathogen interaction. Exogenous application of MeJA induced in tobacco an increase in the transcripts level of the defence related genes lipoxygenase, allene oxide cyclase and defensin and a decrease in the severity of the infection. Qualitative and quantitative differences in volatile compounds emission were showed also in MeJA-treated plants, where the emission of (E)-β-ocimene was significantly increased instead (E)-2-hexenal was not detected. Application of (E)-2-hexenal reduced the severity of powdery mildew while application of (E)-β-ocimene did not. Since (E)-2-hexenal did not activate in tobacco the accumulation of the above reported genes transcripts and the plant cell death, the reduction of the infection severity could be attributable to its inhibitory activity on the fungal germ tube growth. Our data highlight the contributions of natural substances that can act, directly or indirectly, against phytopathogens. In the global context of sustainability, food safety and environmental protection, such semiochemicals represent an alternative and promising approach to integrated pest management., (Copyright © 2011 Elsevier Masson SAS. All rights reserved.)

Diltiazem (DTZ) is an optically active calcium channel blocker having a benzodiazepine structure. The drug used in therapy is (+)-cis-diltiazem with configuration (2S,3S). To describe the analytical profile of DTZ different stationary phases (RP-18, RP-8, monolithic support) were tested. The best separation of DTZ from A, B, E and F was obtained using as stationary phase a RP-8 or a monolithic RP-18. The characterization of impurities was carried out using two analytical systems, HPLC and HPLC/MS.

The lipophilicity of some cardiovascular drugs was determined by capillary electrophoresis (CE). Mexiletine, amlodipine and indapamide, the drugs considered, were in contact with liposomial vescicles for 2, 4 or 6 h. After the contact time the drugs, penetrated into liposomial vesicles, were determined by CE using phosphate buffer (pH 6.3 or 7.4) or borate buffer (pH 9). The lipophilicity of three drugs was determined considering the drug percentage penetrated into liposomial vesicles. The found lipohilicity order was amlodipine > mexiletine > indapamide.

Pethidine, predominantly a mu-receptor agonist, is a phenyl-piperidinic synthetic drug. It is used in the management of moderate to several pain. A possible hydrolytic degradation of an ester group can generate a very toxic compound, the N-methyl-4-phenyl-1,2,3,6 tetrahydropyridine (MPTP) which contaminates the drug. Because of the toxicity of MPTP a suitable method for its determination must be selective and sensitive. Afterwards we propose simple methods to determine pethidine and MPTP by capillary electrophoresis (CE), MECK and RP-high performance liquid chromatography (HPLC) looking at the limit of detection obtained using these three techniques. CE was carried out using as running buffer ammonium acetate (pH 8.3). MECK was performed with a borate buffer (pH 8.3) containing sodium dodecylsulphate and trimethyl-beta-cyclodextrins. RP-HPLC was carried out on a RP18 stationary phase, using as mobile phase a mixture of phosphate buffer (pH 7) containing acetonitrile and 1% of diethylamine.

Capillary Electrophoresis (CE) and Capillary Electrochromatography (CEC) have been used to determine losartan and hydrochlorothiazide. The CE separation was carried out in an uncoated capillary filled with a 100 mM sodium borate pH 9 solution containing trimethyl-beta-cyclodextrins. CEC was performed using a capillary packed with a RP-18 stationary phase. The mobile phase was a mixture of 50 mM ammonium acetate pH 7, water, acetonitrile (1/1.5/7.5). By CE and CEC suitable methods to determine simultaneously losartan and hydrochlorothiazide in working standard mixture or pharmaceutical form were obtained. The proposed methods are very simple and both gave accurate and precise results.

A method for the simultaneous determination of losartan potassium and hydrochlorothiazide in tablets is described. The procedure, based on the use of reversed-phase high-performance liquid chromatography, is linear in the concentration range 3.0-7.0 microg ml(-1) for losartan and 0.5-2.0 microg ml(-1) for hydrochlorothiazide, is simple and rapid and allows accurate and precise results. The limit of detection was 0.08 microg ml(-1) for losartan and 0.05 microg ml(-1) for hydrochlorothiazide.

Background and Objectives: Desmoplastic small round cell tumor (DSRCT) is an increasingly recognized entity with a historically poor prognosis. This article describes the present clinical management of these patients., Methods: We retrospectively reviewed our experience with 40 histologically proven cases of desmoplastic small round cell tumor diagnosed between 7/1/72 and 10/1/99. Thirty-five of these patients are the subjects of a previous report. Demographic data, mode of presentation, completeness of resection, and overall survival were assessed., Results: The overall survival from DSRCT remains very poor and in our series was 29% at three years from diagnosis. There is a significant correlation between use of intense alkylator therapy (P6 protocol), and gross total resection with improved overall survival. It is often technically feasible to remove large peritoneal masses using a tangential dissection technique. Extensive hepatic parenchymal or hilar involvement or extensive infiltration of the diaphragm in the region of the septum transversum and hepatic veins usually makes gross total resection impossible with a corresponding worsened prognosis., Conclusion: We recommend induction chemotherapy (P6) followed by aggressive surgical debulking and external beam radiotherapy for the treatment of DSRCT. Further progress will require new forms of treatment.

The supposed 5-LO inhibitory activity of two N-omega-ethoxycarbonyl-4-quinolones was tested determining leukotriene B4 (LTB4) in RBL-1 cell cultures, pretreated with the two compounds of interest. LTB4, obtained by solid-phase extraction (SPE) from cell cultures supernatants, was determined by micellar electrokinetic chromatography (MEKC). The analysis was performed using an uncoated capillary, filled with borate buffer at pH 8.3, containing 12.5 mM SDS as micelles generator. Therefore, following the decreasing of LTB4 it was possible to verify the 5-LO inhibitory activity of two quinolone derivatives. To asses the suitability of the use of LTB4 as marker of the activity of the new compounds, the analysis was repeated using quercetin, a well known 5-LO inhibitor.

Silybine (SBN), isosilybine (ISBN), silycristine (SCN), silydianine (SDN), and taxifoline (TXF) are the main active flavanoids, generally found in the dried fruits of silybum marianum. The concentrations of these compounds, excepted TXF, are all together usually expressed as silymarine content. In this paper the determination of the silymarine titre was made by high performance liquid chromatography (HPLC), and high performance capillary electrophoresis (HPCE). Two reversed stationary phases, RP-18 and RP-8, were observed comparing the resolutions of all considered flavanoids with each stationary phases. The HPCE was carried out considering the possible improvement in the resolution of SBN, CN, SDN and TXF using, 8-cyclodextrines or organic modifier. The qualitative and quantitative data obtained by HPLC and HPCE were compared.

Human alpha1-acid glycoprotein (alpha1-AGP) has been used as a chiral stationary phase (CSP) for the enantioseparation of midodrine and deglymidodrine racemates in the same HPLC run. The imobilized AGP resulted as the best chiral selector for the enantioresolution of two compounds. Due to the modification of alpha1-AGP characters as a result of changing the composition of the mobile phase, an attempt study of the watery mobile phase (ionic strength and pH of the buffer, nature and concentration of the organic modifier) allowed for an increase in the enantioselectivity of the chromatographic system and an optimization of the resolution base-line of both enantiomeric pairs.

A high-performance capillary zone electrophoretic (HPCE) assay has been developed for the determination of ursodeoxycholic acid (UDCA) and its usual impurities. Considering the low molecular absorptivity of UDCA and its related compounds indirect UV detection was used. The electrophoretic capillary was filled with a background electrolyte (BGE) containing an UV absorbing ion: benzoic acid (BA) or 5,5-diethylbarbituric acid (DBA). To enhance the selectivity of the assay diimethyl-beta-cyclodextrines (D-beta-CDs) or trimethyl-beta-cyclodextrines (T-beta-CDs) have been added to the running buffer together with methylcellulose or urea. All considered impurities were well resolved with two buffers studied, with the exception of methylursodehoxycholate, a neutral compound.

A modified Hummel-Dreyer method was used to study the binding of drugs with serum proteins by high performance capillary electrophoresis. The study was carried out to check the possible interaction between serum proteins and a highly selective beta 2-blocker, ICI 118551 (ICI). To prove the suitability of the method the protein binding of frusemide and ceftriaxone, drugs previously investigated, was also studied. The analyses were carried out by injecting a solution of s alpha(1)-acidic glycoprotein (alpha(1)-AGP) or human serum albumin in 70 mM NaH2PO4/Na2HPO4(pH 7.4) buffer into an uncoated fused silica capillary filled with the same buffer. In the capillary, maintained at a working temperature of 35 degrees C, a known amount of the ICI, frusemide or ceftriaxone was added. The method allows the bound drug to be determined directly.

Aqueous alcoholic mallow flower extracts were analyzed both by HPTLC-densitometry in the reflectance mode at 530 nm and by reversed-phase HPLC with gradient elution. For the mallow flower anthocyanins the best chromatographic resolution was obtained by HPLC, which revealed only two main compounds, confirmed by FAB-MS: malvidin 3,5-O-diglucoside (malvin) and malvidin 3-O-(6"-O-malonylglucoside)-5-O-glucoside. The HPTLC densitometric method on cellulose plates provides accuracy, reproducibility and selectivity for the quantitative analysis of the anthocyanins and this method was shown to be much more sensitive than the HPLC-DAD system, at 530 nm. Both methods give comparable quantitative results for total anthocyanins when applied to mallow flowers from two different sources: Italy and Albania.

A simple capillary electrophoretic method was developed for the analysis of a new generation of serotonergic anxiolytics and their related substances: zalospirone, gepirone, ipsapirone and buspirone. All compounds run in a Tris/phosphate buffer at pH 3 as cations and the experimental conditions allowed good resolution of four drugs and their principal impurities. The analyses were made using two different kinds of capillary. The suitability of CZE and HPLC methods for the analysis of these non-benzodiazepinic anxiolytic agents and their impurities was compared.

A simple, rapid and reproducible high-performance thin-layer chromatographic (HPTLC) method using UV or fluorescence scanning densitometry has been developed for the assay and purity control of methoxymorpholinodoxorubicin hydrochloride (FCE 23762). With a mobile phase of chloroform-methanol-acetic acid (93:6:1, v/v/v) and a silica gel plate, all potential impurities were separated from the main component and from each other. Detection limits at a signal-to-noise ratio of 2:1 were a few nanograms for UV detection and < 1 ng for fluorescence emission. The RSD values for the examined compounds were all < 3%.

Capillary electrophoresis has been used to analyse ticlopidine and its main impurities in bulk material. The minimum detectable amount of impurities was determined and the electrophoretic conditions used were discussed. The proposed method is also suitable to analyse the drug in plasma.

A simple isocratic procedure was developed for the analysis of new serotonergic anxiolytics and the related compounds in bulk materials, pharmaceutical formulations and in biological samples. The system may be applied for the assay of other serotonergic anxiolytics of related structure such as buspirone. The liquid chromatographic assay utilizes a reversed-phase C18 column, a mobile phase consisting of a mixture (55:45, v/v) of (A) buffer potassium dihydrogen phosphate (0.05 M) containing sodium lauryl sulphate (0.005 M) and (B) acetonitrile. A fluorescence detection is used with lambda ex 237 nm; lambda cm 374 nm. The accuracy, precision and sensitivity of the proposed method are established. Standard curves are linear with respect to concentration in the range 0.05-7.5 micrograms ml-1. The method also allows the separation and identification of related compounds at concentrations below 0.01%.

A variety of racemic flavanoids with anti-rhinovirus activity have been resolved for the first time by HPLC, using a chiral stationary phase. Baseline separation was easily obtained for racemic 4',6-dichloroisoflavan (V). The absolute configurations of two enantiomers (Va and Vb) were established by comparing their circular dichroism curves with those of other known isoflavans. Both the isomers were tested against human rhinovirus serotype 1B infection in vitro; the S form was approximately four times more effective than the R form.

A room temperature photochemical spectrofluorimetric (RTPF) method has been developed for the assay of phenylbutazone (PB), and its major degradation products. Fluorescence spectral properties of PB, its degradation products, and their photoproducts are reported, as well as the optimal irradiation times (ranging from 4 to 45 min), which correspond to maximum fluorescence signals of photoproducts. Linear log-log calibration plots were obtained over a 50- to 1000-fold range of concentration, and limits of detection ranged between 1 ng/ml and 1.2 micrograms/ml. This has been shown to be a convenient technique, in terms of simplicity, short measurement times, sensitivity, and precision.