Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:Q86TM3 (cage)
 29,987 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Synthesis of the first fully characterized, water-soluble boronated phthalocyanine is reported. Reaction of 4-nitrophthalonitrile with dimethyl malonate in the presence of base yielded dimethyl (3,4-dicyanophenyl)malonate which was converted into dimethyl (3,4-dicyanophenyl)propargylmalonate by sequential treatment with potassium hydroxide and propargyl bromide. Formation of the o-carborane cage was accomplished by reaction of the alkyne with decaborane in acetonitrile at reflux. High-temperature solid state condensation of the resulting o-carboranylphthalonitrile with cobalt(II) chloride followed by ester deprotection and cation exchange provided the water-soluble closo-carbonylphthalocyanine product. The product contains 40 boron atoms (27% boron by weight) and may be useful as a tumor-seeking boron delivery agent for boron neutron capture therapy of cancer.
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PMID:Synthesis and Characterization of a Boronated Metallophthalocyanine for Boron Neutron Capture Therapy. 1166 77

Thousands of soldiers who served in the Gulf War have symptoms that have been collectively termed Gulf War Illness (GWI). It has been suggested that a combination of operational stress and pyridostigmine, a drug given as a pretreatment to protect soldiers against the effects of exposure to nerve agents, might have had unexpected adverse health effects causing these symptoms. Our laboratory has previously modeled operational stress in rats using a paradigm of around-the-clock intermittent signalled footshock. In the present studies, this model was used to investigate the potential synergistic effects of chronic stress and pyridostigmine on physiology and behavior. Seventy-two rats were trained to perform an alternation lever pressing task to earn their entire daily food intake. The rats were then implanted with osmotic minipumps containing vehicle, pyridostigmine (25 mg/ml pyridostigmine bromide) or physostigmine (20 mg/ml eserine hemisulfate). The pumps delivered 1 microl/h, which resulted in a cumulative dosing of approximately 1.5 mg/kg/day of pyridostigmine or 1.2 mg/kg/day of physostigmine, equimolar doses of the two drugs. The rats were then returned to their home cages where performance continued to be measured 24 h/day. After 4 days, 24 of the 72 rats were trained to escape signalled footshock (avoidance-escape group) and 24 other rats (yoked-stressed group) were each paired to a rat in the avoidance-escape group. The remaining 24 rats were not subjected to footshock (unstressed group). Shock trials were intermittently presented in the home cage 24 h/day for 3 days, while alternation performance continued to be measured. Since only 12 test cages were available, each condition was repeated to achieve a final n of six rats per group. Pyridostigmine and physostigmine each decreased blood acetylcholinesterase levels by approximately 50%. Physostigmine also decreased brain cortical acetylcholinesterase levels by approximately 50%, while pyridostigmine had no effect on cortical acetylcholinesterase activity. Alternation performance was impaired on the first day of stress and then recovered. Neither pyridostigmine nor physostigmine affected performance in the absence of stress or increased the effects of stress alone. Corticosterone was significantly increased in the yoked stress group compared to unstressed controls. These data suggest that pyridostigmine does not exacerbate the effects of stress on performance or levels of stress hormones. Furthermore, these data do not suggest that stress enables pyridostigmine to cross the blood brain barrier.
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PMID:The combined effects of pyridostigmine and chronic stress on brain cortical and blood acetylcholinesterase, corticosterone, prolactin and alternation performance in rats. 1170 Nov 90

Four macrotricyclic cage hosts which feature four positive binding sites oriented toward the center of the intramolecular cavity are presented as promising candidates for anion receptors and they have been expected to play a important role in the selective encapsulation of the halide ion Cl- or Br . The complementarity between a macrotricyclic quaternary ammonium ion and Cl- was achieved by fine-tuning of the four ammonium nitrogen atoms and the endocyclic methylene groups. The cage hosts [R4N4(C5H10)4(C6H12)2]4+ (abbreviated as [556]) showed perfect encapsulation of all chloride ions in acetonitrile at 0 < r= ([Cl-]o/[[556]]o) < or = 1 within the sensitivity of the 1H NMR spectra in combination with a rather slow chemical exchange of the Cl- ion in an encapsulation/decapsulation equilibrium with [556]. Further, the selective encapsulation of all the chloride ions into [556] cage occurs unambiguously at r = 1 in the presence of equimolar amounts of Br-. The structural complementarity of the newly designed [556] host prevails over the Hofmeister-series restraints determined by differences in Gibbs free energy of halide anion solvation.
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PMID:Selective encapsulation of chloride ions within novel cage host complexes in the presence of equimolar amounts of chloride and bromide ions. 1177 82

A variety of S-alkylated products was prepared by alkylation of methyl thioethers [MeSB(12)H(11)](2-) (5), [1-(MeS)-2(7,12)-(Me(2)S)B(12)H(10)](-) (6-8), and [1,2(7,12)-(MeS)(2)B(12)H(10)](2-) (9-11) with alkyl halides and tosylates in acetonitrile. Since these methyl thioethers can be prepared easily in B-10-enriched form on a large scale and due to their chemical versatility, they are potentially very attractive boron entities for the design and synthesis of therapeutics for boron neutron capture therapy of cancer. It was found that alkylation of 6-8 can be complicated by an equilibrium which establishes between, on the one hand, one of the former species and, on the other hand, 1,2(7,12)-(Me(2)S)(2)B(12)H(10) (2-4) and [1,2(7,12)-(MeS)(2)B(12)H(10)](2-) (9-11). A boronated phosphonate 1-(MeS(CH(2))(4)P(O)(OEt)(2))-7-(Me(2)S)B(12)H(10) (14g) and a gem-bisphosphonate 1-(MeS(CH(2))(3)CH[P(O)(OEt)(2)](2))-7-(Me(2)S)B(12)H(10) (14h) were prepared from thioether 7 and the corresponding iodide and tosylate, respectively, and subsequently converted to their sodium salts. The propargyl sulfonium salts obtained by alkylation of thioethers 7, 8, 10, and 11 with propargyl bromide have been further converted to two- and three-cage oligomers containing both ortho-carborane and dodecaborane moieties. Methyl thioethers derived from closo-[B(12)H(12)](2-) are excellent participants in Michael addition reactions in the presence of a strong acid. The sulfonium salts with tertiary alkyl and vinyl substituents have been prepared by this method. Methyl thioethers 5-11 react with hydroxylamine-O-sulfonate yielding the corresponding aminosulfonium salts, albeit in lower yields as compared to those in the alkylation reactions. Several derivatives of methyl thioethers 5-11 have been characterized by single-crystal X-ray diffraction.
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PMID:S-alkylation and S-amination of methyl thioethers--derivatives of closo-[B(12)H(12)](2-). synthesis of a boronated phosphonate, gem-bisphosphonates, and dodecaborane-ortho-carborane oligomers. 1189 Aug 12

Caged reagents are photoactivatable molecules with applications in biological research. While a great deal of work has been carried out on small caged molecules, less has been done on caged macromolecules, such as proteins. Caged proteins would be especially useful in signal transduction research. Since most proteins involved in cell signaling are regulated by phosphorylation, a means to cage phosphorylated proteins would be generally applicable. Here we show that the catalytic subunit of protein kinase A can be activated by thiophosphorylation at Thr-197. The modified protein can then be caged with 4-hydroxyphenacyl bromide to yield a derivative with a specific catalytic activity that is reduced by approximately 17-fold. Upon photolysis at near UV wavelengths, an approximately 15-fold increase in activity is observed, representing an approximately 85-90% yield of uncaged product with a quantum yield phi(P) = 0.21. Because protein kinases belong to a superfamily with structurally related catalytic domains, the protein chemistry demonstrated here should be applicable to a wide range of signaling proteins.
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PMID:Catalytic subunit of protein kinase A caged at the activating phosphothreonine. 1210 99

Suitable probe molecules containing the benzophenone chromophore and one dissociable bond [perester 1 or C-X (4, 5)] or two such bonds (2, 3) have been synthesized and studied to examine intramolecular triplet energy dispersion. Triplet energies and phosphorescence quantum yields as well as quantum efficiencies of bond scissions have been studied, and the flow of triplet energy in such molecules is discussed. Upon irradiation at 350 nm in either benzene or methanol, the target peresters undergo dissociation of both cleavable groups, producing a pair of radicals. The presence of a benzylic chloride function has little influence on the efficiency of perester dissociation. However, the presence of a benzylic bromide function was found to decrease the quantum yield of decomposition of the perester function of 3. This can be explained by taking into account the effect of the heavy atom and the rate of cage geminate radical pair recombination. The nature of the heavy atom perturbation, however, was found to be different in 5 as compared with 3.
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PMID:Triplet energy distribution in photoinitiators containing two dissociable groups. 1218 51

The use of 1,3,5-triaminocyclohexane (tach) as a capping ligand in generating metal-cyanide cage clusters with accessible cavities is demonstrated. The precursor complexes [(tach)M(CN)(3)] (M = Cr, Fe, Co) are synthesized by methods similar to those employed in preparing the analogous 1,4,7-triazacyclononane (tacn) complexes. Along with [(tach)Fe(CN)(3)](1)(-), the latter two species are found to adopt low-spin electron configurations. Assembly reactions between [(tach)M(CN)(3)] (M = Fe, Co) and [M'(H(2)O)(6)](2+) (M' = Ni, Co) in aqueous solution afford the clusters [(tach)(4)(H(2)O)(12)Ni(4)Co(4)(CN)(12)](8+), [(tach)(4)(H(2)O)(12)Co(8)(CN)(12)](8+), and [(tach)(4)(H(2)O)(12)Ni(4)Fe(4)(CN)(12)](8+), each possessing a cubic arrangement of eight metal ions linked through edge-spanning cyanide bridges. This geometry is stabilized by hydrogen-bonding interactions between tach and water ligands through an intervening solvate water molecule or bromide counteranion. The magnetic behavior of the Ni(4)Fe(4) cluster indicates weak ferromagnetic coupling (J = 5.5 cm(-)(1)) between the Ni(II) and Fe(III) centers, leading to an S = 6 ground state. Solutions containing [(tach)Fe(CN)(3)] and a large excess of [Ni(H(2)O)(6)](2+) instead yield a trigonal pyramidal [(tach)(H(2)O)(15)Ni(3)Fe(CN)(3)](6+) cluster, in which even weaker ferromagnetic coupling (J = 1.2 cm(-)(1)) gives rise to an S = (7)/(2) ground state. Paralleling reactions previously performed with [(Me(3)tacn)Cr(CN)(3)], [(tach)Cr(CN)(3)] reacts with [Ni(H(2)O)(6)](2+) in aqueous solution to produce [(tach)(8)Cr(8)Ni(6)(CN)(24)](12+), featuring a structure based on a cube of Cr(III) ions with each face centered by a square planar [Ni(CN)(4)](2)(-) unit. The metal-cyanide cage differs somewhat from that of the analogous Me(3)tacn-ligated cluster, however, in that it is distorted via compression along a body diagonal of the cube. Additionally, the compact tach capping ligands do not hinder access to the sizable interior cavity of the molecule, permitting host-guest chemistry. Mass spectrometry experiments indicate a 1:1 association of the intact cluster with tetrahydrofuran (THF) in aqueous solution, and a crystal structure shows the THF molecule to be suspended in the middle of the cluster cavity. Addition of THF to an aqueous solution containing [(tach)Co(CN)(3)] and [Cu(H(2)O)(6)](2+) templates the formation of a closely related cluster, [(tach)(8)(H(2)O)(6)Cu(6)Co(8)(CN)(24) superset THF](12+), in which paramagnetic Cu(II) ions with square pyramidal coordination are situated on the face-centering sites. Reactions intended to produce the cubic [(tach)(4)(H(2)O)(12)Co(8)(CN)(12)](8+) cluster frequently led to an isomeric two-dimensional framework, [(tach)(H(2)O)(3)Co(2)(CN)(3)](2+), exhibiting mer rather than fac stereochemistry at the [Co(H(2)O)(3)](2+) subunits. Attempts to assemble larger edge-bridged cubic clusters by reacting [(tach)Cr(CN)(3)] with [Ni(cyclam)](2+) (cyclam = 1,4,8,11-tetraazacyclotetradecane) complexes instead generated extended one- or two-dimensional solids. The magnetic properties of one of these solids, two-dimensional [(tach)(2)(cyclam)(3)Ni(3)Cr(2)(CN)(6)]I(2), suggest metamagnetic behavior, with ferromagnetic intralayer coupling and weak antiferromagnetic interactions between layers.
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PMID:High-nuclearity metal-cyanide clusters: synthesis, magnetic properties, and inclusion behavior of open-cage species incorporating [(tach)M(CN)3] (M = Cr, Fe, Co) complexes. 1261 5

A tosylated azacryptand readily protonates at the bridgehead amines, becoming a potential ditopic anion receptor. The in-in conformation of the amines facilitates encapsulation of two bromide guests and represents the first structural evidence that a proton cage cryptate can bind two anions internally.
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PMID:A ditopic azacryptate proton cage. 1465 62

In the presence of chloride or bromide in the appropriate mixture of solvents, 6 equiv of nickel(II) and 8 equiv of Hatu [Hatu=H2NC(=NH)NHC(=S)NH2] assemble to yield the metallacages [Ni6(atu)8X][ClO4]3 (atu=deprotonated form of Hatu; X=Cl, 5; Br, 6) where four "units" of the square-planar complex Ni(atu)2 are coordinated to two further nickel centers, forming an octahedral cage around an encapsulated chloride or bromide anion. Synthesis of the cages is highly dependent on the nature of the anions and the solvents used. In methanol, the cage only forms if chloride is present; in a mixture of acetone/methanol, the cage forms in the presence of either chloride or bromide. An interesting feature of the templation process is that there is a dramatic color change associated with assembly of the building blocks in the presence of the appropriate anion to yield the cages. This color change has been used as the basis for the colorimetric detection of chloride anions in methanol. The reaction of 4 equiv of nickel(II), 8 equiv of Hatu, and 2 equiv of platinum(II) has also been carried out, yielding the mixed-metal cage [Pt2Ni4(atu)8Cl][ClO4]3 (7a); the X-ray crystal structure of this compound is reported herein.
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PMID:Anion-templated synthesis of metallacages as a means for the colorimetric detection of chlorides. 1555 24

Multiwalled carbon nanotubes (MWCNTs) were used as the active elements for the first time for affinity-based elimination of ionic dyes. MWCNTs were encapsulated in cross-linked alginate (ALG) microvesicles using Ba2+ as the bridging ion. The Ba2+-alginate matrix constitutes a cage which holds the physically trapped MWCNTs. The cage carries negative charges on its surface. The cage restricts the access of anions of large molecular weight, such as humic acids, because of electrostatic repulsion. The cage also restricts the access of colloids of large size, because of size exclusion. Ionic dyes partition into the cage and then are captured by MWCNTs probably on the basis of van der Waals interactions occurring between the hexagonally arrayed carbon atoms in the graphite sheet of MWCNTs and the aromatic backbones of the dyes. As a result of these interactions the target species, namely, the ionic dyes, are eliminated efficiently by the MWCNTs of Ba2+-ALG/MWCNT composite adsorbents. The adsorptive capacities for elimination of acridine orange, ethidium bromide, eosin bluish, and orange G (the model species used for this study) were found as high as 0.44, 0.43, 0.33, and 0.31 micromol, respectively, for 1.0 mg of the caged MWCNTs. Adsorptive experiments with carbon nanofibers and activated carbons as the adsorbents were also performed. The MWCNT-based adsorbents provided the best capability for the affinity-based elimination of these targeted species. Biocompatibility experiments performed in vitro and in vivo provided promising results, suggesting potential applications of the caged MWCNTs in in situ environmental remediation.
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PMID:Caged multiwalled carbon nanotubes as the adsorbents for affinity-based elimination of ionic dyes. 1566 54


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