Search results for "SoMe"
showing 10 items of 5114 documents
Crystallization and preliminary X-ray studies of mouse centrin1.
2005
The expression, purification, crystallization and preliminary X-ray diffraction studies of mouse centrin1 are reported. Centrins belong to a family of Ca{sup 2+}-binding EF-hand proteins that play a fundamental role in centrosome duplication and the function of cilia. To shed light on the structure–function relationship of these proteins, mouse centrin1 has been crystallized. The mouse centrin1 has been expressed in Escherichia coli as a GST-centrin fusion protein containing a thrombin protease cleavage site between the fusion partners. Two constructs with different linking-sequence lengths were expressed and purified. Thrombin cleavage yielded functional centrin1 and N-terminally extended …
11H‑Pyrido[3′,2′:4,5]pyrrolo[3,2‑c]cinnoline and Pyrido[3′,2′:4,5]pyrrolo[1,2‑c][1,2,3]benzotriazine: Two New Ring Systems with Antitumor Activity
2014
Derivatives of new ring systems 11H-pyrido[3',2':4,5]pyrrolo[3,2-c]cinnoline and pyrido[3',2':4,5]pyrrolo[1,2-c][1,2,3]benzotriazine have been prepared from the key intermediates 2-(1H-pyrrolo[2,3-b]pyridin-2-yl)anilines in excellent yields (94-99%) and screened by the National Cancer Institute (Bethesda, MD) on about 60 human tumor cell lines derived from nine cancer cell types. The tested compounds exhibited antiproliferative activity against all the human cell lines, showing comparable MG_MID (mean graph midpoint) values in the range of 0.74-1.15 μM. A particular efficacy was observed against the leukemia subpanel (GI50 = 0.73-0.0090 μM). Flow cytometric analysis of the cell cycle demons…
Regioselective substitution of 6,7-dichloroquinoline-5,8-dione: synthesis and X-ray crystal structure of 4a,10,11-triazabenzo[3,2-a]fluorene-5,6-dion…
2003
6,7-Dichloroquinoline-5,8-dione (1) was reacted with a number of 2-aminopyridine derivatives. Of the several possible products of this reaction, 4a,10,11-triazabenzo[3,2-a]fluorene-5,6-dione (6), produced by condensation and rearrangement, was obtained as the major product, and its structure was subsequently unambigously determined by X-ray crystallographic study. Ortho-quinones were produced via nucleophilic substitution at position C7, which was unexpected, considering that para-quinones were produced via C6 substitution in the reaction between compound 1 and ethyl acetoacetate in our previous work. Such unexpected nucleophilic substitution at C7 provides an effective, yet simple route, t…
The introduction of fluorine atoms or trifluoromethyl groups in short cationic peptides enhances their antimicrobial activity
2006
The effect of introducing fluorine atoms or trifluoromethyl groups in either the peptidic chain or the C-terminal end of cationic pentapeptides is reported. Three series of amide and ester peptides were synthesised and their antimicrobial properties evaluated. An enhanced activity was found in those derivatives whose structure contained fluorine, suggesting an increase in their hydrophobicity.
Synthesis and pharmacology of 6-substituted benztropines: discovery of novel dopamine uptake inhibitors possessing low binding affinity to the dopami…
2005
A series of 6alpha- and 6beta-substituted benztropines were synthesized. A marked enantioselectivity was observed for the 6beta-methoxylated benztropines, the (1R)-isomers being more potent than the corresponding (1S) compounds. The racemic 6alpha-methoxy-3-(4',4' '-difluorodiphenylmethoxy)tropane (5 g) was the most potent compound. It has been found that modifications at the 6-position of benztropine might reduce the DAT binding affinity, maintaining otherwise a significant dopamine uptake inhibitory activity. A reinvestigation of the absolute configuration of 6beta-methoxytropinone proved the 6R configuration for the (+)-enantiomer.
Mass spectra of methoxychlorobenzenes (chloroanisoles)
1988
Electron impact mass of all 19 ring-substituted chloroanisoles have been investigated. The fragmentation pathways were elucidated with the aid of the 1st field-free region metastable ions. The greatest disparity between the spectra of the positional isomers is shown with the [M−CH 3 ] + and [M−CH 2 O] +• ions, i.e., the ortho and para isomers preferentially lose • CH 3 , whereas the meta isomers generally show both loss of • CH 3 and elimination of formaldehyde, the latter process being more dominant with the meta-monochloro and di- and trichloro isomers having two meta-chlorine atoms. Characteristic for all isomers is also the abundant M +• and [M−CH 3 −CO] + ions, the other fragmentation …
Determination of the electron-detachment energies of 2'-deoxyguanosine 5'-monophosphate anion: influence of the conformation.
2009
The vertical electron-detachment energies (VDEs) of the singly charged 2'-deoxyguanosine 5'-monophosphate anion (dGMP - ) are determined by using the multiconfigurational second-order perturbation CASPT2 method at the MP2 ground-state equilibrium geometry of relevant conformers. The origin of the unique low-energy band in the gas phase photoelectron spectrum of dGMP - , with maximum at around 5.05 eV, is unambiguously assigned to electron detachment from the highest occupied molecular orbital of π-character belonging to guanine fragment of a syn conformation. The presence of a short H-bond linking the 2-amino and phosphate groups, the guanine moiety acting as proton donor, is precisely resp…
Stereoselective metabolism of dibenz(a,h)anthracene to trans-dihydrodiols and their activation to bacterial mutagens.
1990
Dibenz(a,h)anthracene (DBA), a carcinogenic, polycyclic aromatic hydrocarbon ubiquitous in the environment, is metabolized by the hepatic microsomal fraction of immature Sprague-Dawley rats pretreated with Aroclor 1254 to 27 ethyl acetate-extractable metabolites. More than half of these metabolites (51%) consisted of trans-1,2-; -3,4-; and -5,6-dihydrodiols including their identified secondary metabolites. The three trans-dihydrodiols (4.9, 15.8, and 0.6% of total metabolic conversion) were highly enriched in their R,R enantiomers (85, 71, and 98%) as determined by high performance liquid chromatography on suitable chiral stationary phases. This is explained on the basis of the stereoselect…
Folding Patterns in a Family of Oligoamide Foldamers
2015
A series of small, unsymmetrical pyridine-2,6-dicarboxylamide oligoamide foldamers with varying lengths and substituents at the end groups were synthetized to study their conformational properties and folding patterns. The @-type folding pattern resembled the oxyanion-hole motifs of enzymes, but several alternative folding patterns could also be characterized. Computational studies revealed several alternative conformers of nearly equal stability. These folding patterns differed from each other in their intramolecular hydrogen-bonding patterns and aryl-aryl interactions. In the solid state, the foldamers adopted either the globular @-type fold or the more extended S-type conformers, which w…
Structure and properties of hydroxyl radical modified nucleic acid components II. 8-Oxo-adenine and 8-oxo-2′-deoxy-adenosine
1997
Abstract The tautomerism of the 8-oxo-adenine (8-oxo-A) and 8-oxo-2′-deoxy-adenosine (8-oxo-dA) was analysed on the basis of semiempirical, SCF ab initio and DFT density functional quantum chemistry calculations. The results of full gradient geometry optimisation of all possible 8-oxo-A and 8-oxo-dA structures lead to the conclusion that the most stable form is 8-keto-6-amino-tautomer. The second stable tautomer corresponds to 8-hydroxy-isomer. Such an order was unchanged after solvating process. In all studied solvents: water, methanol, acetone, cyclohexane the keto-tautomer proceeds the enol one. The preferred N-glycoside torsion angle corresponds to syn rotamer of 8-oxo-dA in all studied…