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Several Products (several + products)
Selected AbstractsPhysical, chemical and environmental properties of selected chemical alternatives for the pre-plant use of methyl bromide as soil fumigantPEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 2 2006Luis O Ruzo Abstract Production and use of methyl bromide, a soil fumigant, are being restricted because of this chemical's deleterious effects on stratospheric ozone concentrations. Several products, some of which are currently used as soil fumigants, are being considered as possible replacements for methyl bromide, alone and in various combinations. Among these, 1,3-dichloropropene, methyl isothiocyanate generators such as metam-sodium, and chloropicrin are currently registered, while others such as methyl iodide and sodium azide are at different stages of the registration process. This review examines physicochemical properties, environmental fate, and metabolism of the various potential methyl bromide replacement products. Copyright © 2005 Society of Chemical Industry [source] Analyses of alkaloids in different products by NACE-MSELECTROPHORESIS, Issue 22 2007Chen-Wen Chiu Abstract A simple method for the separation and characterization of five nicotine-related alkaloids by NACE employing UV and MS detections is described here for the first time. Several factors, including NACE parameters (compositions of running solution) and MS parameters (such as nature and flow rate of sheath liquid, pressure of nebulization gas, and flow rate of dry gas), were optimized in order to obtain both an adequate CE separation and high MS signals for the alkaloid compounds used in this study. A reliable CE separation of five alkaloids was achieved in 50,mM ammonium formate that was dissolved in an ACN/methanol mixture (50:50, v/v) of pH*,4.0 (apparent pH 4.0). The optimal electrospray MS measurement was carried out in the positive ionization mode using a coaxial sheath liquid composed of isopropyl alcohol and water in the ratio of 80:20 v/v at a flow rate of 180,,L/h. In addition, the proposed NACE method was also applied in the analyses of alkaloids in several products including chewing gums, beverages, and tobaccos. This NACE-MS method was found to provide a better detection ability and separation resolution for the analysis of nicotine alkaloids when compared to other aqueous CE-MS reports. [source] Asymmetric Homoaldol Reactions with Cyclohex-2-enyl N,N -Diisopropylcarbamate: Kinetic Resolution, Elucidation of the Stereochemical Course and Applications in the Synthesis of Hexahydroisobenzofuran-4-(1H)-onesEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 20 2007Jochen Becker Abstract Enantio-enriched cyclohex-2-enyl N,N -diisopropylcarbamate (5) is stereospecifically deprotonated by sec -butyllithium/(,)-sparteine (9) to form the configurationally stable lithium complex 7·9. A kinetic resolution of rac - 5 by n -butyllithium/(,)-sparteine (9) yielded (R)- 5 with up to 99,% ee. Electrophilic substitution with tin electrophiles proceeds in a anti -SE, fashion as shown by chemical correlations. The synthesized allylstannanes 10 undergo a highly stereospecific TiCl4 -mediated homoaldol reaction with various aldehydes, yielding syn -configured homoaldol products 12. These were transferred into all - cis -configured hexahydroisobenzofuran-4(1H)-ones 22 by BF3·OEt2 -mediated reactions with aldehydes. The configurations of several products were determined by X-ray structure analysis. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007) [source] Heterologous expression of a Rauvolfia cDNA encoding strictosidine glucosidase, a biosynthetic key to over 2000 monoterpenoid indole alkaloidsFEBS JOURNAL, Issue 8 2002Irina Gerasimenko Strictosidine glucosidase (SG) is an enzyme that catalyses the second step in the biosynthesis of various classes of monoterpenoid indole alkaloids. Based on the comparison of cDNA sequences of SG from Catharanthus roseus and raucaffricine glucosidase (RG) from Rauvolfia serpentina, primers for RT-PCR were designed and the cDNA encoding SG was cloned from R. serpentina cell suspension cultures. The active enzyme was expressed in Escherichia coli and purified to homogeneity. Analysis of its deduced amino-acid sequence assigned the SG from R. serpentina to family 1 of glycosyl hydrolases. In contrast to the SG from C. roseus, the enzyme from R. serpentina is predicted to lack an uncleavable N-terminal signal sequence, which is believed to direct proteins to the endoplasmic reticulum. The temperature and pH optimum, enzyme kinetic parameters and substrate specificity of the heterologously expressed SG were studied and compared to those of the C. roseus enzyme, revealing some differences between the two glucosidases. In vitro deglucosylation of strictosidine by R. serpentina SG proceeds by the same mechanism as has been shown for the C. roseus enzyme preparation. The reaction gives rise to the end product cathenamine and involves 4,21-dehydrocorynantheine aldehyde as an intermediate. The enzymatic hydrolysis of dolichantoside (N,-methylstrictosidine) leads to several products. One of them was identified as a new compound, 3-isocorreantine A. From the data it can be concluded that the divergence of the biosynthetic pathways leading to different classes of indole alkaloids formed in R. serpentina and C. roseus cell suspension cultures occurs at a later stage than strictosidine deglucosylation. [source] Asymmetric Lithiation of Boron Trifluoride-Activated Aminoferrocenes: An Experimental and Computational InvestigationADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 11-12 2010Costa Metallinos Abstract Tertiary aminoferrocenes complexed to boron trifluoride (BF3) are shown to undergo asymmetric lithiation with alkyllithiums in the presence of bulky chiral 1,2-diaminocyclohexane ligands. This reaction represents the first BF3 -activated asymmetric lithiation of a prochiral aromatic amine and the first such transformation to be mediated by a chiral diamine other than (,)-sparteine. The process provides rapid access to a broad range of enantiomerically enriched 2-substituted-1-aminoferrocenes, including derivatives with uncommon substitution patterns that are of interest in catalysis. The enantioselectivity of the process is high enough (87:13 to 91:9 er) to allow for isolation of single enantiomers of several products after simple recrystallization as either the free aminoferrocenes or their ammonium fluoroborate salts. Both antipodes of the planar chiral 2-substituted-1-aminoferrocene products are accessible, as confirmed by single crystal X-ray diffraction analysis of two compounds with opposite relative stereochemistry. Single-point calculation of thirty-two different transition states of the reaction at the M06-2X/6-311+g(2d,2p) level produced a computational model that correctly predicted both the sense and extent of chiral induction. Three factors appeared to play important roles in determining enantioinduction during lithiation of BF3 -complexed tertiary aminoferrocenes: (i) the maintenance of a highly organized eight-membered ring transition state; (ii) the existence of a strong Li,,,F contact which placed the chiral diamine ligand in close proximity to the ferrocene substrate; (iii) the orientation of the sterically demanding N -alkyl groups of the chiral diamine additives, either away or towards, the aminoferrocene and the alkyllithium. The model may serve as a predictive tool for the rational design of new ligands for this and related asymmetric lithiations. [source] Synthesis of polycyclic polyfunctionalized carbocycles by a cobalt(I)-initiated tandem diels,alder reaction sequence,ISRAEL JOURNAL OF CHEMISTRY, Issue 4 2001Gerhard Hilt The cobalt(I)-catalyzed neutral Diels,Alder reaction of acyclic 1,3-dienes with conjugated enynes can be used to generate secondary dihydroaromatic 1,4,8-trienes containing a 1,3-diene substructure, in good yields under mild reaction conditions. These 1,3-dienes can be converted, with reactive dienophiles in a tandem normal Diels,Alder reaction, into polycyclic compounds. In a similar tandem Diels,Alder sequence, the cobalt-catalyzed neutral homo Diels,Alder reaction of 2,5-norbornadiene can be used to generate polycyclic cycloaddition adducts. A sequential triple Diels,Alder reaction sequence can be realized when norbornadiene is reacted with the excess of the conjugated enynes under cobalt(I) catalysis. In a homo Diels,Alder, neutral Diels,Alder, normal Diels,Alder reaction sequence, the intermediately formed adducts are reacted with activated dienophiles to yield polycyclic compounds in a short sequence. The structures of several products were established by X-ray analysis. This showed that predominantly endo-products are formed in the tandem reaction sequences, while the exo-product becomes predominant in the triple Diels,Alder reaction sequence. [source] Localization of nucleophosmin in nuclear matrix and changes in its expression during the differentiation of human neuroblastoma induced by retinoic acid,JOURNAL OF CELLULAR BIOCHEMISTRY, Issue 1 2010Song-Lin Shi Abstract In this article, we selectively extracted the nuclear matrix and intermediate filament system of human neuroblastoma SK-N-SH cells pre- and post-treated with retinoic acid (RA). The distribution of nucleophosmin (NPM) in the nuclear matrix and its colocalization with several products of related genes were investigated. Results from two-dimensional gel electrophoresis and MALDI-TOF showed that NPM was a component of the nuclear matrix and its expression in SK-N-SH cells post-treated with RA was down-regulated. Immunofluorescent microscopy observations further showed that NPM was localized in the nuclear matrix of SK-N-SH cells, and its expression level and distribution were altered after treatment with RA. The colocalization of NPM with c-myc, c-fos, p53, and Rb in SK-N-SH cells was observed under a laser scanning confocal microscope, but the colocalization region was changed by RA. Our results prove that NPM is a nuclear matrix protein, which is localized in nuclear matrix fibers. The colocalization of NPM with its related genes and oncogenes affect the differentiation of SK-N-SH cells. The expression of NPM and its distribution in the process of cell differentiation deserve more intensive investigation. J. Cell. Biochem. 111: 67,74, 2010. © 2010 Wiley-Liss, Inc. [source] PRESERVATION OF "UMBU" (SPONDIAS TUBEROSA ARRUDA CÂMARA) PULP IN THE GREEN STAGE OF MATURATION BY COMBINED METHODSJOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 3 2007ELIDA CONCEIÇÃO JORGE ABSTRACT "Umbu" (Spondias tuberosa Arruda Câmara) is a typical fruit from northeastern Brazil of considerable economic importance to this region, because several products are derived from it and commercialized, especially the pulp, which can be used as a raw material for preserves and juices. The objective of this research was to study the preservation of umbu in the green stage of maturation by combined methods, including heat treatment and the addition of preservatives and sucrose. The pulps were blanched, pasteurized and mixed with the preservatives and sucrose according to a complete factorial design with three variables (ratio pulp/sucrose, potassium sorbate and sodium metabisulfite), two levels and two repetitions. The products were filled into high-density polyethylene packages and exposed to a temperature of 40C for 120 days. Physicochemical, color and chemical (SO2) analyses showed that the concentrations of sodium metabisulfite and potassium sorbate used did not significantly alter product quality. The addition of sucrose significantly decreased the water activity and led to intense browning. The microbiological evaluations showed good product stability for 120 days. The overall results indicated that the heat treatment applied was effective if high levels of hygiene were maintained during the preparatory stages and the packaging materials were well sanitized. The combined preservation methods appear to be an economic way to preserve these high-acid pulps. [source] Identification and characterization of microsatellites in eggplantPLANT BREEDING, Issue 3 2003T. Nunome Abstract The potential of microsatellite markers for use in genetic studies in eggplant, Solanum melongena, has been evaluated. A genomic library of eggplant was screened for GA and GT repeat motifs to isolate microsatellite clones. The frequency of each repeat motif in the eggplant genome was found to be every 3200 kb for GA repeats and every 820 kb for GT repeats. Sixty-one per cent of GT repeats were found to directly flank AT repeats. A total of 37 polymerase chain reaction (PCR) primer pairs were designed, 23 of which amplified a single product or several products. The level of microsatellite polymorphism was evaluated by using S. melongena lines and related Solanum species. Two to six alleles per primer pair were displayed in the S. melongena lines and two to 13 alleles were displayed in the Solanum relatives. Seven microsatellites showed polymorphism between parental lines of the mapping population and segregated in a codominant Mendelian manner. These microsatellite loci were distributed throughout the linkage map. [source] Thermal Decomposition of Energetic Materials 84: Pyrolysis of 5-Substituted 1,3,5-TrinitrohexahydropyrimidinesPROPELLANTS, EXPLOSIVES, PYROTECHNICS, Issue 2 2003Brian Abstract Results of slow and fast pyrolysis were compared for 1,3,5-trinitrohexahydropyrimidine compounds in which the 5-position was substituted by H, CH3, NO2, CH2ONO2, and CH2N3. IR and Raman spectroscopy were used to identify and quantify all of the gaseous products. The decomposition process appears to be initiated by reactions at the 5-position of the ring. The gases produced are rather similar for all of the compounds, however the different functional groups impart their own signature on the concentrations of several products. [source] What about Design Newness?THE JOURNAL OF PRODUCT INNOVATION MANAGEMENT, Issue 6 2009Investigating the Relevance of a Neglected Dimension of Product Innovativeness In several industries, new products are very similar in functional features but compete on their unique design. Firms like Alessi, Apple, Bang & Olufsen, Dyson, or Kartell all follow a design-driven innovation approach and use their products' visual appearance as the main mean for differentiation. In spite of this, design newness is never discussed among the dimensions of product innovativeness. Instead, conceptualizations of product innovativeness mostly focus on a product's technical newness or the changes it implies for the innovating firm or for the market it enters. This paper seeks to build an argument for why design newness should be considered as a dimension of product innovativeness. In addition to providing conceptual rationale, empirical evidence is offered on the influence of design newness on sales performance across a product's life cycle. To be able to put the findings into perspective, the performance effects of design newness are compared with those of technical newness. As several products exemplify that design newness and technical newness can go hand in hand, not only direct performance effects but also interaction effects between both newness dimensions are investigated. The arguments are tested on a sample of 157 new cars launched between 1978 and 2006 in Germany. The automobile industry is selected because of the strategic role of both technical and design aspects in product innovation. Putting a focus on this industry also has the advantage that historical information on car specifics and objective sales data over time are accessible. The results emphasize that both design and technical newness are important drivers of car sales. However, the effects differ widely across the product life cycle. While design newness has a positive impact right after the introduction and persists in strength over time, technical newness drives sales with a lagged effect and decreases toward the end of the life cycle. The test of a combined influence of design newness and technical newness on sales performance produces no significant results. These results open interesting avenues for future research on product innovativeness in general and design newness in particular. For management practice, the findings emphasize the importance of overall product innovativeness, clarify the different performance effects of design and technical newness across the product life cycle, and show the value of creating a unique visual product appearance to positively trigger product diffusion. [source] | ||||||||||||||||||||||