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1.
Zusammenfassung Ersatz vonp-Toluolsulfosäure durch Oxal- oder, bevorzugt, Adipinsäure in Salmis Methode für die Synthese von 5-3-Äthylendioxysteroiden führt zu 4-3-Äthylendioxysteroiden.

Paper XXIV; paper XXIII seeS. Bernstein andR. Littell, J. org. Chem.26, 3610 (1961).  相似文献   

2.
Summary In synthesizing 6-(4-pyridyl)-3-mercapto-1,2,4-tria-zin-5-one from the oxime of 4-pyridyl-glyoxylic acid, isonicotinaldehyde-thiosemicarbazone is obtained through decarboxilation as a by-product, which is mainly responsible for the tuberculostatic properties.  相似文献   

3.
Zusammenfassung An Glukorons?ure gebundenes 1-(3′-Methoxy-4′-hydroxy-phenyl)-6, 7-dimethoxy-chinolin ist als Metabolit des Papaverins beim Menschen und bei S?ugetieren erkannt und isoliert worden. Ein in den Lebermikrosomen enthaltenes Ferment, dassauerstoff-und TPNH-abh?ngig ist, bewirkt die Methoxylspaltung, und ein weiteres Ferment übertr?gt die Glukurons?ure aus ihrer Verbindung mit Uridinphosphat auf die entstandene phenolische Verbindung.   相似文献   

4.
Summary The essentiality of (-6) and (-3) fatty acids in mammals is well known. Nevertheless, some important points remain unclear concerning their implication in physiology. After a short discussion about the definition of essential fatty acids deficiency, this brief overview deals with some of these points, pointing out some of the unresolved questions. Different subjects are approached concerning the (-6) and (-3) fatty acids metabolism: desaturases, eicosanoids, production, as well as some of their metabolic effects on cell membranes, intestinal function, glucose and lipid metabolism, haemorheology.  相似文献   

5.
D-6-Methyl-8-[-isopropylaminoethyl] ergoline-I [VÚFB-10726], beginning from the dose of 0.05 mg/kg p.o., suppresses lactation through the inhibition of prolactin secretion in nursing rats.  相似文献   

6.
The laminin-binding integrin α6β4 plays key roles in both normal epithelial and endothelial cells and during tumor cell progression, metastasis, and angiogenesis. Previous cysteine mutagenesis studies have suggested that palmitoylation of α6β4 protein supports a few integrin-dependent functions and molecular associations. Here we took another approach and obtained strikingly different results. We used overexpression and RNAi knockdown in multiple cell types to identify protein acyl transferase DHHC3 as the enzyme responsible for integrin β4 and α6 palmitoylation. Ablation of DHHC3 markedly diminished integrin-dependent cellular cable formation on Matrigel, integrin signaling through Src, and β4 phosphorylation on key diagnostic amino acids (S1356 and 1424). However, unexpectedly, and in sharp contrast to prior α6β4 mutagenesis results, knockdown of DHHC3 accelerated the degradation of α6β4, likely due to an increase in endosomal exposure to cathepsin D. When proteolytic degradation was inhibited (by Pepstatin A), rescued α6β4 accumulated intracellularly, but was unable to reach the cell surface. DHHC3 ablation effects were strongly selective for α6β4. Cell-surface levels of ~10 other proteins (including α3β1) were not diminished, and the appearance of hundreds of other palmitoylated proteins was not altered. Results obtained here demonstrate a new substrate for the DHHC3 enzyme and provide novel opportunities for modulating α6β4 expression, distribution, and function.  相似文献   

7.
Summary During the conversion of cholesterol into 3 -hydroxymethyl-A-nor-5-cholestane by the spongeAxinella verrucosa, the carbon-3 of this latter originate from carbon-4 of cholesterol. Cholestanol moreover does not seem an intermediate in this conversion.  相似文献   

8.
采用标准0.5μmGaAsPHEMT工艺设计了工作频段在2.4—6GHz可应用于无线局域网(WLAN)和超宽带(UWB)接收机的超宽带低噪声放大器。从宽带电路的选择、高频电路设计的器件选择和电路结构的选择等方面讨论了如何进行超宽带低噪声放大器的设计。结果表明,通过合适的电路结构和器件参数选择,可以采用0.5μmGaAsPHEMT工艺制备满足超宽带系统要求的低噪声放大器。在UWB3.1~5.15GHz低频带内,该LNA增益20.8~21.6dB,噪声系数低于0.9~1.1dB,输入输出驻波比均小于一10dB。在2.4~3GHz频带(涵盖802.11b/g的使用范围)内,该LNA增益20.8~21.5dB,噪声系数低于2dB,输入输出驻波比均小于-10dB。在频带5.2—6GHz,该LNA的噪声系数增大到1.332dB。增益则从21.4dB下降到19.7dB。电路的工作电压为3.3V。  相似文献   

9.
There is considerable evidence suggesting that the switch from to and chain production after birth is due, in part, to silencing of the genes by stage-specific factors which bind to their promoters and to the competition from the adult ( and ) genes for a common enhancer element located in the locus control region. As a consequence one can expect that the increased Hb F production in adults with hereditary persistence of fetal hemoglobin or -thalassemia is directed mainly by -globin genes in cis to the deletion(s) responsible for these conditions. Here we review data on heterozygotes with -, -, or -thalassemia, who also had anAT mutation, in cis or in trans, which was used as a marker of gene expression. The results show that a deletion affecting adult genes favors the expression of genes in cis, while the deletion of a single gene does not affect the expression of the gene in cis but leads to a faster switch postnatally.  相似文献   

10.
Résumé L'ingestion du cancérogène 3-méthyl-4-diméthylaminoazobenzène pendant 40 jours inhibe fortement l'induction de la tryptophane pyrrolase du foie des rats causée par leL-tryptophane ou bien l'hydrocortisone. Les auteurs montrent que cet effet est dû à la perte du cofacteur de la tryptophane pyrrolase des mitochondries et des microsomes des animaux soumis au régime alimentaire cancérogène.  相似文献   

11.
Summary -(4-chlorophenyl)-GABA, a GABA mimetic compound, acts as an inhibitor of GABA metabolism in both synaptosomal and extrasynaptosomal compartments. It has no significant action on GABA or Glu uptake by synaptosomes.  相似文献   

12.
Summary N-(5-Phosphopyridoxyl)-4-aminobutyric acid, a stable adduct of pyridoxal phosphate and 4-aminobutyric acid, has been shown to be a potent inhibitor of rat brain 4-aminobutyric acid aminotransferase (GABA-T) with a Ki of 1.4 M.Acknowledgments. This work was supported in part by the United Parkinson Foundation, l'Association Canadienne l'Ataxie de Friedreich, and the Medical Research Council of Canada.  相似文献   

13.
Summary The C-terminal amino acid sequences of human and of porcine antithrombin III have been determined as Gly-Arg-Val-Ala-Asn-Pro-Cys-Val-Lys and Gly-Arg-Val-Ala-Asn-Pro-Cys, respectively. These sequences are highly homologous with the C-terminal sequence of human -1-proteinase inhibitor.  相似文献   

14.
15.
Summary 2--Glucosyl-4-hydroxy-7-methoxy-1,4-benzoxazin-3-one (DIMBOA-Glc), the main hydroxamic acid from maize and wheat, and its aglucone, decreased survival ofSchizaphis graminum reared on artificial diets. Both compounds were toxic for aphids and acted as feeding deterrents, at concentrations as low as 1 mM. The natural concentrations of glucosides of hydroxamic acids in wheat leaves reach up to 6 mmoles/kg fresh weight, thus falling within the range in which DIMBOA-Glc causes delecterious effects to diet-fed aphids.To whom correspondence should be addressed. THis work was supported by grants from International Foundation for Science (484), Universidad de Chile (N-1654) and the Agency for International Development.  相似文献   

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19.
Toll-like receptors (TLRs) act as sensors of microbial components and elicit innate immune responses. All TLR signaling pathways activate the nuclear factor-kappaB (NF-κB), which controls the expression of inflammatory cytokine genes. Transforming growth factor-β-activated kinase 1 (TAK1) is a serine/threonine protein kinase that is critically involved in the activation of NF-κB by tumor necrosis factor (TNFα), interleukin-1β (IL-1β) and TLR ligands. In this study, we identified a novel protein, WD40 domain repeat protein 34 (WDR34) as a TAK1-interacting protein in yeast two-hybrid screens. WDR34 interacted with TAK1, TAK1-binding protein 2 (TAB2), TAK1-binding protein 3 (TAB3) and tumor necrosis factor receptor-associated factor 6 (TRAF6) in overexpression and under physiological conditions. Overexpression of WDR34 inhibited IL-1β-, polyI:C- and lipopolysaccharide (LPS)-induced but not TNFα-induced NF-κB activation, whereas knockdown of WDR34 by a RNA-interference construct potentiated NF-κB activation by these ligands. Our findings suggest that WDR34 is a TAK1-associated inhibitor of the IL-1R/TLR3/TLR4-induced NF-κB activation pathway. D. Gao and R. Wang contributed equally to this work.  相似文献   

20.
Summary Leydig cell nuclear area and 5-3-hydroxysteroid dehydrogenase activity were increased in the testis ofBufo melanostictus 2 days after a single short-term cold exposure. Both parameters returned to normal values 4 days later.  相似文献   

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