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Many Compounds (many + compound)
Selected AbstractsEffect of cigarette smoke extract on the polymorphonuclear leukocytes chemiluminescence: influence of a filter containing glutathioneLUMINESCENCE: THE JOURNAL OF BIOLOGICAL AND CHEMICAL LUMINESCENCE, Issue 2 2005B. Zappacosta Abstract Cigarette smoking is known to be a risk factor for several chronic and neoplastic diseases. Many compounds formed by cigarette burning, ranging from particulate materials to water solutes and gaseous extracts, are considered to be noxious agents, and many biochemical and molecular mechanisms have been proposed for the toxic effects of cigarette smoke. The oral cavity and the upper respiratory tract represent the first contact areas for smoke compounds; even a single cigarette can produce marked effects on some components of the oral cavity, either chemical compounds, such as glutathione and enzymes, or cellular elements, such as polymorphonuclear leukocytes. Several studies suggest a protective role of glutathione against the noxious effects of tobacco smoke; the sulphydril groups of glutathione, in fact, could react with some smoke products, such as unsaturated aldehydes, leading to the formation of harmless intermediate compounds and simultaneously preventing the inactivation of metabolically essential molecules, such as some enzymes. In this paper we analyse the effect of a filter containing glutathione on the respiratory burst of polymorphonuclear leukocytes exposed to aqueous extract of cigarette smoke, measuring their chemiluminescence activity. The results of this paper indicate that the GSH--containing filter has a likely protective effect against the inhibition of cigarette smoke extract on polymorphonuclear leukocyte activity. Copyright © 2005 John Wiley & Sons, Ltd. [source] Natural products that have been used commercially as crop protection agentsPEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 6 2007Leonard G Copping Abstract Many compounds derived from living organisms have found a use in crop protection. These compounds have formed the basis of chemical synthesis programmes to derive new chemical products; they have been used to identify new biochemical modes of action that can be exploited by industry-led discovery programmes; some have been used as starting materials for semi-synthetic derivatives; and many have been used or continue to be used directly as crop protection agents. This review examines only those compounds derived from living organisms that are currently used as pesticides. Plant growth regulators and semiochemicals have been excluded from the review, as have living organisms that exert their effects by the production of biologically active secondary metabolites. Copyright © 2007 Society of Chemical Industry [source] Characterisation of varnishes used in violins by pyrolysis-gas chromatography/mass spectrometryRAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 23 2008Giuseppe Chiavari The correct characterisation and a detailed knowledge of the materials originally used in violin varnishes, like natural resins, is crucial for the conservation in museums and for a suitable restoration technique. The study presented here reports on the potential of pyrolysis (Py) coupled with gas chromatography (GC) and mass spectrometry (MS) for the identification of chemical markers of each resin; this tecnique is very sensitive and selective, it needs a small quantity of sample and does not require chemical treatments. To improve the chromatographic behaviour of polar compounds the derivatising agent tetramethylammonium hydroxide (TMAH) in combination with pyrolysis has been used, in the so-called TMAH thermochemolysis or thermally assisted hydrolysis and methylation (THM), or more simply pyrolysis-methylation. The natural resins studied were colophony, sandarac, manila copal, elemi, amber and benzoin, mainly composed of terpenic compounds, with the exception of the latter, composed of aromatic compounds. Many compounds were identified; in particular, methyl esters of resinous acids that, individually or in a group, can be used as chemical markers. However, through this technique it was not possible to distinguish between the sandarac and manila copal resins because their chromatographic behaviour is very similar. Finally, the procedure applied has been employed in the characterisation of original varnish samples. Copyright © 2008 John Wiley & Sons, Ltd. [source] Cover Picture: Biotechnology Journal 5/2006BIOTECHNOLOGY JOURNAL, Issue 5 2006Article first published online: 11 MAY 200 Cover illustration: Chirality is omnipresent in nature: Many compounds contain an asymmetric center and thus can occur in two non-superimposable mirror-image forms (enantiomers). The two enantiomers of a chiral compound often have dramatically different effects, as exemplified by the thalidomid catastrophe. Therefore, only one enantiomer is needed for the production of active substances in the pharmaceutical or agricultural industry. It is an important aspect in white biotechnology, to take advantage of highly specific catalysts of (micro-) biological origin for the synthesis of enantiopure compounds. Biocatalysis indeed is a highly efficient process and an example of environmentally friendly, ,green' chemistry, requiring relatively low energy inputs, mild solvents and generating minimal byproducts. Image © Wacker. [source] Pharmaceuticals and Other Organic Waste Water Contaminants Within a Leachate Plume Downgradient of a Municipal LandfillGROUND WATER MONITORING & REMEDIATION, Issue 2 2004Kimberlee K. Barnes Ground water samples collected from the Norman Landfill research site in central Oklahoma were analyzed as part of the U.S. Geological Survey (USGS) Toxic Substances Hydrology Program's national reconnaissance of pharmaceuticals and other organic waste water contaminants (OWCs) in ground water. Five sites, four of which are located downgradient of the landfill, were sampled in 2000 and analyzed for 76 OWCs using four research methods developed by the USGS. OWCs were detected in water samples from all of the sites sampled, with 22 of the 76 OWCs being detected at least once. Cholesterol (a plant and animal steroid), was detected at all five sites and was the only compound detected in a well upgradient of the landfill. N,N-diethyltoluamide (DEBT used in insect repellent) and tri(2-chloroethyl) phosphate (fire-retardant) were detected in water samples from all four sites located within the landfill-derived leachate plume. The sites closest to the landfill had more detections and greater concentrations of each of the detected compounds than sites located farther away. Detection of multiple OWCs occurred in the four sites located within the leachate plume, with a minimum of four and a maximum of 17 OWCs detected. Because the landfill was established in the 1920s and closed in 1985, many compounds detected in the leachate plume were likely disposed of decades ago. These results indicate the potential for long-term persistence and transport of some OWCs in ground water. [source] Halitosis among racially diverse populations: an updateINTERNATIONAL JOURNAL OF DENTAL HYGIENE, Issue 1 2008S Rayman Abstract:, The aim of this paper is to highlight the cultural perceptions of halitosis to dental professionals. Halitosis (oral malodour or bad breath) is caused mainly by tongue coating and periodontal disease. Bacterial metabolism of amino acids leads to metabolites including many compounds, such as indole, skatole and volatile sulphur compounds (VSC), hydrogen sulphide, methyl mercaptan and dimethyl sulphide. They are claimed to be the main aetiological agents for halitosis. Gastrointestinal diseases are also generally believed to cause halitosis. In general, physicians and dentists are poorly informed about the causes and treatments for halitosis. The paper reviews the prevalence and distribution of halitosis, oral malodour, its aetiology, concepts of general and oral health and diseases and their perception among racially diverse population. Eating, smoking and drinking habits and understanding of halitosis as a social norm among different people has been highlighted. The treatment options have also been presented very briefly. A brief discussion about general importance within existing healthcare services has been highlighted. Oral malodour may rank only behind dental caries and periodontal disease as the cause of patient's visits to the dentist. It is a public social health problem. The perception of halitosis is different in culturally diverse populations. So the dental professionals should be aware of the cultural perceptions of halitosis among racially and culturally diverse populations. There is a need to integrate the cultural awareness and knowledge about halitosis among the dental professional for better understanding of halitosis to treat patients with the social dilemma of halitosis to improve the quality of life and well-being of individuals with the problem. It is concluded that dental professionals (especially dental hygienists) should be prepared to practice in a culturally diverse environment in a sensitive and appropriate manner, to deliver optimal oral health and hygiene care. [source] The extraordinary ligand binding properties of human serum albuminIUBMB LIFE, Issue 12 2005Mauro Fasano Abstract Human serum albumin (HSA), the most prominent protein in plasma, binds different classes of ligands at multiple sites. HSA provides a depot for many compounds, affects pharmacokinetics of many drugs, holds some ligands in a strained orientation providing their metabolic modification, renders potential toxins harmless transporting them to disposal sites, accounts for most of the antioxidant capacity of human serum, and acts as a NO-carrier. The globular domain structural organization of monomeric HSA is at the root of its allosteric properties which are reminiscent of those of multimeric proteins. Here, structural, functional, biotechnological, and biomedical aspects of ligand binding to HSA are summarized. [source] Enhancement of antibiotic and secondary metabolite detection from filamentous fungi by growth on nutritional arraysJOURNAL OF APPLIED MICROBIOLOGY, Issue 6 2008G.F. Bills Abstract Aims:, We asked to what extent does the application of the OSMAC (one strain, many compounds) approach lead to enhanced detection of antibiotics and secondary metabolites in fungi? Protocols for bacterial microfermentations were adapted to grow fungi in nutritional arrays. Methods and Results:, Protocols for microfermentations of non-sporulating fungi were validated using known antifungal-producing fungi. Detection of antifungal activity was often medium dependent. The effects of medium arrays and numbers of strains on detection of antifungal signals were modelled by interpolation of rarefaction curves derived from matrices of positive and negative extracts. Increasing the number of fermentation media for any given strain increased the probability of detection of growth inhibition of Candida albicans. Increasing biodiversity increased detection of antifungal phenotypes, however, nutritional arrays could partly compensate for lost antibiotic phenotypes when biodiversity was limiting. Conclusions:, Growth and extraction in microtiter plates can enable a discovery strategy emphasizing low-cost medium arrays that can better exploit the metabolic potential of strains. Significance and Impact of the Study:, Increasing fermentation parameters raise the probability of detecting bioactive metabolites from strains. The protocols can be used to pre-select strains and their growth conditions for scale up that will most likely yield antibiotics and secondary metabolites. [source] On the performance of some aromaticity indices: A critical assessment using a test setJOURNAL OF COMPUTATIONAL CHEMISTRY, Issue 10 2008Ferran Feixas Abstract Aromaticity is a central chemical concept widely used in modern chemistry for the interpretation of molecular structure, stability, reactivity, and magnetic properties of many compounds. As such, its reliable prediction is an important task of computational chemistry. In recent years, many methods to quantify aromaticity based on different physicochemical properties of molecules have been proposed. However, the nonobservable nature of aromaticity makes difficult to assess the performance of the numerous existing indices. In the present work, we introduce a series of fifteen aromaticity tests that can be used to analyze the advantages and drawbacks of a group of aromaticity descriptors. On the basis of the results obtained for a set of ten indicators of aromaticity, we conclude that indices based on the study of electron delocalization in aromatic species are the most accurate among those examined in this work. © 2008 Wiley Periodicals, Inc. J Comput Chem, 2008 [source] Cutaneous allergic reactions to tattoo inkJOURNAL OF COSMETIC DERMATOLOGY, Issue 4 2009Ravneet Ruby Kaur BSN Summary Tattoo artists use many compounds to create tattoo pigment and several allergic reactions can occur as a result of these additives. The compositions of many inks have been identified; however, as new mixtures are created it becomes difficult to identify the specific ingredients in a particular ink. Allergic reactions to a particular pigment can manifest in several ways including allergic contact dermatitis and photoallergic dermatitis. Subsequently, tattoo ink or pigment allergy reactions can be classified as acute inflammatory reactions, allergic hypersensitivities, and granulomatous, lichenoid, and pseudolymphomatous types of reactions. This paper will review the clinical manifestations and the most common compounds associated with cutaneous reactions to tattoo ink. [source] An efficient synthesis of [13C6]-3,5-dichloroanilineJOURNAL OF LABELLED COMPOUNDS AND RADIOPHARMACEUTICALS, Issue 7 2008Bachir Latli Abstract 3,5-Dichloroaniline is commonly found in many compounds with pharmacological and other biological activities. [13C6]-Aniline or its hydrochloride salt was converted in three steps to [13C6]-3,5-dichloroaniline, which can be incorporated in compounds of interest and used as internal standards in drug metabolism and pharmacokinetics (DMPK) studies. Copyright © 2008 John Wiley & Sons, Ltd. [source] Measurement of dissociation constants (pKa values) of organic compounds by multiplexed capillary electrophoresis using aqueous and cosolvent buffers,JOURNAL OF PHARMACEUTICAL SCIENCES, Issue 7 2008Marina Shalaeva Abstract Evaluation of a multiplexed capillary electrophoresis (CE) method for pKa measurements of organic compounds, including low solubility compounds, is presented. The method is validated on a set of 105 diverse compounds, mostly drugs, and results are compared to literature values obtained from multiple references. Two versions of the instrument in two different labs were used to collect data over a period of 3 years and inter-laboratory and inter-instrument variations are discussed. Twenty-four point aqueous and mixed cosolvent buffer systems were employed to improve the accuracy of pKa measurements. It has been demonstrated that the method allows direct pKa measurements in aqueous buffers for many compounds of low solubility, often unattainable by other methods. The pKa measurements of compounds with extremely low solubility using multiplexed CE with methanol/water cosolvent buffers are presented. © 2008 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 97:2581,2606, 2008 [source] Gas-phase formation of protonated benzene during collision-induced dissociation of certain protonated mono-substituted aromatic molecules produced in electrospray ionizationRAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 11 2010Min Li Protonated benzene, C6H, has been studied extensively to understand the structure and energy of a protonated organic molecule in the gas phase. The formation of C6H is either through direct protonation of benzene, i.e., chemical ionization, or through fragmentation of certain radical cations produced from electron ionization or photon ionization. We report a novel observation of C6H as a product ion formed in the collision-induced dissociation (CID) of protonated benzamide and related molecules produced via electrospray ionization (ESI). The formation of C6H from these even-electron precursor ions during the CID process, which has not been previously reported, is proposed to occur from the protonated molecules via a proton migration in a five-membered ring intermediate followed by the cleavage of the mono-substituent CC bond and concurrent formation of an ion-molecule complex. This unique mechanism has been scrutinized by examining some deuterated molecules and a series of structurally related model compounds. This finding provides a convenient mean to generate C6H, a reactive intermediate of considerable interest, for further physical or chemical investigation. Further studies indicate that the occurrence of C6H in liquid chromatography/electrospray ionization tandem mass spectrometry (LC/ESI-MS/MS) appears to be a rather common phenomenon for many compounds that contain ,benzoyl-type' moieties. Hence, the observation of the C6H ion in LC/ESI-MS/MS can be used as an informative fragmentation pathway which should facilitate the identification of a great number of compounds containing the ,benzoyl-type' and similar structural features. These compounds are frequently present in food and pharmaceutical products as leachable impurities that require strict control and rapid elucidation of their identities. Copyright © 2010 John Wiley & Sons, Ltd. [source] How to Achieve Confidence in Drug Discovery and Development: Managing Risk (from a Reductionist to a Holistic Approach)CHEMMEDCHEM, Issue 6 2009Annette Bakker Dr. Abstract Confidence in mechanism: Creating a more holistic understanding of disease pathophysiology and an early confidence in the mechanism under investigation could help facilitate the selection of not only the most appropriate targets but also the best mechanisms for disease intervention and how to select and optimise the best compounds. Drug target and candidate selection are two of the key decision points within the drug discovery process for which all companies use certain selection criteria to make decisions on which targets to accept into their discovery pipelines and which compounds will pass into development. These steps not only help define the overall productivity of every company but they are also decisions taken without full predictive knowledge of the risks that lie ahead or how best to manage them. In particular, the process of selecting new targets does not normally involve full evaluation of the risk(s) in the mechanism under investigation (the modulation of the target), which may result in an inability to fully connect in,vitro and animal model results to the disease (clinical) setting. The resulting poor progression statistics of many compounds in the clinic is at least partially the result of a lack of understanding of disease pathophysiology. Notably, the lack of efficacy is still a major reason for failure in the clinic.1 Creating a more holistic understanding of disease pathophysiology and an early confidence in the mechanism under investigation could help facilitate the selection of not only the most appropriate targets but also the best mechanisms for disease intervention and how to select and optimise the best compounds. [source] | ||||||||||||||||