Low Reactivity (low + reactivity)

Distribution by Scientific Domains


Selected Abstracts


Diversity of rice glutelin polypeptides in wild species assessed by the higher-temperature sodium dodecyl sulfate-polyacrylamide gel electrophoresis and subunit-specific antibodies

ELECTROPHORESIS, Issue 6 2008
Nadar Khan
Abstract In efforts to find genetic resources with high nutritional value of rice seed, we assessed the diversity of the major storage protein glutelin in 13 wild and 2 cultivated rice species by a unique SDS-PAGE method and subunit-specific antibodies. Maximum separation of microheterogeneous glutelin ,-polypeptides, which is a prerequisite for the diversity evaluation, could be attained by SDS-PAGE performed at higher temperature (45°C) than the generally employed temperatures (4,25°C). Seven antipeptide antibodies were raised against subunit-specific epitope sequences designed at five sites from four variable regions spanning the glutelin ,-polypeptides. High specificity of each antibody was confirmed using rice glutelin mutants, and demonstrated considerable variation in amino acid sequence and accumulation level of glutelin subunit in wild species, in combination with the higher-temperature SDS-PAGE. The degree of the variation was, however, changed according to the site of variable regions and the type of subunit. Some wild species accumulated nutritious GluB subunits more than cultivated rice. The wild species Oryza longiglumis and O. brachyantha had glutelin with low reactivity against most antibodies examined in this study, reflecting the significant divergence. Such wild species may hopefully serve as important genetic resources for nutritional improvement of cultivated rice. [source]


Discontented people: reactivity and locus of control as determinants of subjective well-being

EUROPEAN JOURNAL OF PERSONALITY, Issue 1 2001
Tatiana Klonowicz
This study examines the effects of reactivity temperament and locus of control variables on subjective well-being (SWB). SWB is operationalized as positive affect, the absence of somatic concerns, and heightened life satisfaction. The study hypotheses were that (1) reactivity and locus of control influenced SWB and that (2) affect either mediated or moderated the influence of these traits on SWB. As expected, high reactivity and external locus of control were associated with lower SWB, whereas low reactivity and internal locus of control were associated with higher SWB. However, the data indicate that reactivity and locus of control influenced different components of SWB and that locus of control predicted SWB more consistently than reactivity. Somatic health is influenced by reactivity, locus of control and negative affect, but not positive affect. Current life satisfaction is influenced by locus of control,but not reactivity,and by both positive and negative affect. Hope is related to reactivity but not to either locus of control or affect. The data corroborate the expectation that affect serves as a mediator in the trait,SWB relations, whereas the view that affect moderates the effect of stable dispositions on SWB finds scant support. Copyright © 2001 John Wiley & Sons, Ltd. [source]


Generation and reactivity of 3-carbethoxy-5-phenyl- 5H,7H -thiazolo[3,4- c]oxazol-4-ium-1-olate

JOURNAL OF HETEROCYCLIC CHEMISTRY, Issue 4 2004
Teresa M. V. D. Pinho e Melo
3-Carbethoxy-5-phenyl-5H,7H -thiazolo[3,4- c]oxazol-4-ium-1-olate was generated from (2R,4R)- N -ethoxyoxalyl-2-phenylthiazolidine-4-carboxylic acid and its reactivity studied. This münchnone showed low reactivity as dipole although from the reaction with dimethyl acetylenedicarboxylate the corresponding (3R)-3-phenyl-17H,3H -pyrrolo[1,2- c]thiazole-5,6,7-tricarboxylate could be isolated. The thermolysis of (2R,4R)- N -ethoxyoxalyl-2-phenylthiazolidine-4-carboxylic acid in refluxing acetic anhydride led to the synthesis of N -(1-ethoxycarbonyl-2-phenylvinyl)-2-phenyl-4-thioxo-1,3-thiazolidine. The structure of methyl (2R,4R)- N -ethoxyoxalyl-2-phenylthiazoliddine-4-carboxylate was determined by X-ray crystallography. [source]


Gas-phase ion chemistry in the ternary SiH4,C3H6,PH3 system

JOURNAL OF MASS SPECTROMETRY (INCORP BIOLOGICAL MASS SPECTROMETRY), Issue 2 2002
Stefania Calderan
Abstract Propene,phosphine and the silane,propene,phosphine gaseous mixtures were studied by ion trap mass spectrometry. For the binary mixture the variation of ion abundances under different partial pressures and the mechanisms of ion,molecule reactions are reported. Moreover, the rate constants of the main processes were measured and compared with the collisional rate constants to determine the reaction efficiencies. In the ternary silane,propene,phosphine mixture the mechanisms of formation of ion clusters were elucidated, but the complexity of the system and the low abundances of the ions usually isolated by successive steps prevented the determination of rate constants. The hydrogenated ternary ions are mainly formed by reactions of ions with propene, whereas a minor contribution comes from reactions of ions with phosphine. The ions show very low reactivity with silane. The formation processes of these species are discussed in relation to their possible role as precursors of amorphous silicon carbides doped with phosphorus obtained by deposition from properly activated silane,propene,phosphine mixtures. Copyright © 2001 John Wiley & Sons, Ltd. [source]


Synthesis of (2E)-2-methyl-3-(4-{[4-(quinolin-2-ylmethoxy)phenyl]sulfanyl}phenyl)prop-2-enoic acid (VUFB 20609) and 2-methyl-3-(4-{[4-(quinolin-2-ylmethoxy)phenyl]sulfanyl}phenyl)propanoic acid (VUFB 20584) as potential antileukotrienic agents

JOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 6 2004
J. Jampílek
The Synthesis of (2E)-2-methyl-3-(4-{[4-(quinolin-2-ylmethoxy)phenyl]sulfanyl}phenyl) prop-2-enoic acid (VUFB 20609) and racemic 2-methyl-3-(4-{[4-(quinolin-2-ylmethoxy) phenyl]sulfanyl}phenyl)propanoic acid (VUFB 20584) as new potential antileukotrienic drugs are described. Due to a low reactivity of the 4-substituted aryl bromides (coupling of the 4-substituted aryl bromides do not provide an activating functional group with 4-methoxybenzene-1-thiol), special conditions, in particular specific heterogeneous copper catalysts, were used. Catalytic hydrogenation of the conjugated double bond on Pd/C in the presence of the sulfanyl group is discussed. In-vitro cytotoxicity testing was performed using a microplate colorimetric acid phosphatase assay. Antiplatelet activity was evaluated using an in-vitro test in human platelet-rich plasma. Some substances inhibited arachidonic acid-induced platelet aggregation. [source]


Vinyl-, Propargyl-, and Allenylsilicon Reagents in Asymmetric Synthesis: A Relatively Untapped Resource of Environmentally Benign Reagents

CHEMISTRY - A EUROPEAN JOURNAL, Issue 22 2009
Marcus
Abstract Green carbanion surrogates: Organotrialkylsilanes occupy a niche in the array of ,green' carbon nucleophiles open to chemists that few other reagents can fill. Despite being known for over 30 years, it is only recently that their true worth in stereoselective carbonyl addition and related processes has started to emerge, primarily due to their low reactivity. It is our hope that this minireview will make the true worth of these reagents more widely known, setting the stage for expanded usage of these versatile yet benign reagents in organic synthesis. An up-to-date in-depth review of the current virtues and limitations in the realm of carbonyl addition reactions with allenyl-, propargyl-, and vinylsilicon reagents, encompassing numerous practical as well as pedagogical principles is presented. Comparisons of chemo-, regio-, and stereoselectivity and reactivity are drawn. Synthetic applications and challenges associated with each class of organosilane are discussed threading together the prospects of these green carbanion surrogates. [source]