1,720,962 research outputs found
MACROCYCLIC POLYESTERS. I. A NOVEL CLASS OF 1,3-BUTANDIOL DERIVATIVES AS POTENTIAL ANTIMICROBIAL AGENTS
No full textThis paper reports the synthesis of a novel class of macrocyclic tetraesters containing 1,3-butandiol sub-units by reacting the stannolan derivative of the diol with diacyl chloride. The structure of the possible isomers was assigned by spectroscopic data and comparison with samples otherwise prepared. Preliminary screening revealed that these compounds have low antimicrobial activity, although it is higher than that of the starting diol
Determination of bezafibrate concentration by high performance liquid-chromatography in serum of rats treated with lead nitrate
No full textIn the present study, the bezafibrate levels were measured in serum of rats treated with lead nitrate using a high performance liquid chromatography (HPLC) method. The results have shown that the peak corresponding to bezafibrate in the chromatogram is reduced in serum of rats treated with bezafibrate plus lead, indicating that lead treatment accelerates the metabolism of bezafibrate in rats. (C) 1998 Elsevier Science S.A. All rights reserved
HDL subfractions as altered in cancer patients
No full textPrevious studies from the authors' laboratories have shown that cancer patients are characterized by lower levels of high-density lipoprotein cholesterol (HDL-C) compared with those of normal subjects. HDLs are a complex class of lipoproteins which can be divided mainly into two categories, HDL(2) and HDL(3), that have not only different lipid and protein composition but also different functions. Therefore, for a better understanding of the metabolism of HDL during tumour growth, the different subfractions of HDL (HDL(2) and HDL(3)) were analysed in the serum of neoplastic patients using a rapid and simple high-performance liquid chromatography (HPLC) method for the analysis. The results obtained showed that serum from neoplastic patients exhibits a peculiar pattern in the distribution of HDL subfractions, consisting of a sharp decrease in HDL(3) and a consequent increase of the normal HDL(2)/HDL(3) ratio. It is suggested that evaluation of the HDL subfractions may be of clinical relevance for cancer status and that due to its simplicity, short analytical time and small sample volume required, the HPLC technique used in this study can be easily applied to routine analysis in cancer patients
New cycloalkylpyrazoles as potential cyclooxygenase inhibitors
No full textIn this study some cycloalkyl-3-(N-substituted carbamoyl)-1-phenylpyrazoles have been synthesized in order to screen their capability to inhibit human cyclooxygenase. The synthetic pathway is based on the well known property of nitrilimines to undergo 1,3-dipolar cycloaddition reactions. The structures of all the synthesized compounds have been elucidated by means of both analytical and spectroscopic methods. (C) 1998 Elsevier Science S.A. All rights reserved
Synthesis of cis- and trans-2-aryl-methyl-cycloalkylamines: potential dopaminergic agents
No full textThis paper reports the synthesis and the study of a few new diastereomeric arylmethylcycloalkylamines, tested as potential dopamine receptor active agents. New procedures for the stereospecific synthesis of the arylmethylcycloalkylamines were successfully experimented. All the considered compounds did not show any appreciable dopamine receptor activity
AN INVESTIGATION INTO THE ELECTRON-IONIZATION-INDUCED MASS-SPECTROMETRIC BEHAVIOR OF SOME TRANS-SUBSTITUTED AND CIS-SUBSTITUTED CYCLOALKYLAMINES OF PHARMACEUTICAL INTEREST
No full textThe electron-ionization-induced mass spectrometric behaviour of eight cyclopentylamine and cyclohexylamine derivatives, recently synthesized, has been investigated by means of accurate mass measurements and metastable ion studies. These approaches allowed an easy structural characterization of the title compounds. In particular, mass-analyzed ion kinetic energy spectroscopy proved effective for the differentiation of cis- vs trans-isomers
MACROCYCLIC POLYESTERS.II. THE PREPARATION OF DIESTER DIAMIDE MACROCYCLES CONTAINING THE 2-AMINOBUTANOL SUB-UNITS AS POTENTIAL ANTIMICROBIAL AGENTS
No full textThis paper reports the synthesis of a novel class of diester diamide macrocycles containing 2-aminobutanol sub-units, by reacting diacyl dichloride with the aminoalcohol or its oxazastannolane derivatives. The structure of the possible isomers was assigned by spectroscopic and analytical data and, when possible by comparison with samples prepared otherwise. The ms spectra of these compounds have been studied and the fragmentation patterns and structures of the main ions are described
Comparative biopharmaceutical properties of commercial lorazepam tablets
No full textThe biopharmaceutical properties of eight lorazepam tablet formulations, marketed in Italy, were studied and compared. A few significant differences in behaviour were found even among similar formulations. In vitro dissolution patterns vazied on varying pH, technological properties, excipients employed and active ingredient concentrations
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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