- INTRAMOLECULAR END-TO-END REACTIONS OF PHOTOACTIVE TERMINAL GROUPS LINKED BY POLYMETHYLENE CHAINS.
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Intramolecular end-to-end reactions of a pair of photoactive terminal groups, dibenz left bracket b,f right bracket azepine (DBA) chromophores, linked by a series of polymethylene chains (DBA-CO(CH//2)//nCO-DBA, n equals 2-30) were studied by two different approaches. One approach is to measure the intramolecular deactivation rate constants of the excited triplet state of terminal DBA groups by the nanosecond laser photolysis and the other is to measure the intramolecular photocyclization rates of these bichromophoric compounds by the quantitative product analysis with GPC. The excited triplet state of the DBA group is the intermediate of the reaction.
- Ashikaga,Ito,Yamamoto,Nishijima
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- Intramolecular hydrogen bonding between remote termini
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[10]-Semirubin (1) and [20]-semirubin (2), with dipyrrinones covalently linked to C10 and C20 fatty acid chains, were synthesized following Friedel-Crafts acylation of the parent 9-H dipyrrinone, (4Z)-2,3,7,8-tetramethyl-(10H)-dipyrrin-1-one, with the diacid chlorides of decanedioic acid and eicosanedioic acid, respectively. Both of these bright yellow pigments are monomeric in CHCl3 solvent: MWobs=394±20 for 1 (formula weight 386), and 533±20 for 2 (formula weight 526) as determined by vapor pressure osmometry (VPO) measurements. In contrast, their methyl esters are dimeric in CHCl3. 1H{1H}-Nuclear Overhauser effects are found between the lactam NH and carboxylic acid OH of 1 and 2, consistent with the type of intramolecular hydrogen bonding found in bilirubin (the yellow pigment of jaundice) and its analogs.
- Huggins, Michael T,Lightner, David A
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- A new general route to thiophenophanes: Synthesis and properties of [n](2,5)thiophenophane-1,n-diones
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A series of [n](2,5)thiophenophane-1,n-diones (5) (n = 9, 10, 12, 14, 16, and 20) were synthesized in a simple four-step route starting from the appropriate 1,ω-oligomethylenedicarboxylic acids. The bis(halomethylketones) (6), which were obtained by successive treatment of the diacids with SOCl2, diazomethane, and HBr or HCl, were cyclized by Na2S under high dilution conditions. The obtained monomeric cyclic diketosulfides (4) were condensed with glyoxal in MeOH by slowly adding dilute NaOMe affording 5. The thiophene-2,5-dicarbonyl moiety of 5 (n = 9) is significantly deformed as shown by X-ray crystallography, and the effect of the strain is reflected in the C=O stretching frequencies and the π-π* and the n-π* absorptions.
- Miyahara, Yuji
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- A process for preparing a fatty acid derivative method and its application (by machine translation)
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The invention discloses a method for preparing a fatty acid derivative method and its application. The first method is the long-chain fatty acid and thionyl chloride reaction, to obtain the acyl chloride; acyl chloride of preparing butanol reaction, then remove chlorine group, and get long-chain fatty acid uncle ding zhi; then and N - hydroxysuccinimide reaction, long-chain fatty acid succinimide and high yield butylacrylate; then with the L - glutamic acid - 1 - tert-butyl reaction, to obtain tert-butyl long-chain fatty acyl - L - Glu - OtBu; with the N - hydroxysuccinimide reaction, to obtain tert-butyl long-chain fatty acyl - L - Glu (OSu)- OtBu; finally [...] butyl long-chain fatty acyl - L - Glu (OSu)- OtBu tert-butyl in removing, and get long-chain fatty acid derivatives. The method routes the operation is simple, quality is controllable, is suitable for industrial production, and low cost, simple purification at the same time, suitable for use in the preparation of high purity insulin analogs. (by machine translation)
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Paragraph 0155-0158
(2018/04/01)
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- Investigation of novel ropinirole analogues: Synthesis, pharmacological evaluation and computational analysis of dopamine D2 receptor functionalized congeners and homobivalent ligands
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Herein, we report the development of novel functionalized congeners of ropinirole toward the design of pharmacological tools to probe structural requirements at the dopamine D2 receptor. Subsequently, we have used the functionalized amine congener 11 and synthesized and pharmacologically evaluated a series of homobivalent ligands of ropinirole with designated spacer lengths ranging from 14 to 30 atoms. The most potent homobivalent ligands (22-, 26- and 30-atom spacers) showed approximately 20- to 80-fold greater potency (EC50 = 3.9, 6.2 and 14 nM, respectively) than ropinirole (304 nM) in a [35S]GTPγS functional assay. Molecular modeling studies suggest that the observed increase in potency of the homobivalent ligands is possibly due to a bitopic binding mode involving the orthosteric site and an allosteric interaction at the dopamine D2 receptor protomer rather than bridging interactions at two orthosteric sites across a dopamine D 2 receptor dimer. This research has the potential to advance the development of structurally related bitopic ligands, biomarkers such as radioligands and fluorescently labeled probes, and furnish new homo- and heterobivalent ligands towards a better understanding of the dopamine D 2 receptor and potential novel treatment for Parkinson's disease.
- J?rg, Manuela,Kaczor, Agnieszka A.,Mak, Frankie S.,Lee, Kiew Ching K.,Poso, Antti,Miller, Neil D.,Scammells, Peter J.,Capuano, Ben
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supporting information
p. 891 - 898
(2014/07/08)
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- Synthesis and binding profile of haloperidol-based bivalent ligands targeting dopamine D2-like receptors
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Homodimers of dopamine D2-like receptors are suggested to be of particular importance in the pathophysiology of schizophrenia and, thus, serve as promising targets for the discovery of atypical antipsychotics. This study describes the development of a series of novel bivalent molecules with a pharmacophore derived from the dopamine receptor antagonist haloperidol. These dimers were investigated in comparison to their monomeric analogues for their D2long, D2short, D3, and D4 receptor binding and the ability to bridge two neighboring receptor protomers. Radioligand binding studies provided diagnostic insights when Hill slopes close to two for the bivalent ligand 13 incorporating 22 spacer atoms and a comparative analysis with monovalent control ligands indicated a bivalent binding mode with a simultaneous occupancy of two neighboring binding sites.
- Salama, Ismail,L?ber, Stefan,Hübner, Harald,Gmeiner, Peter
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supporting information
p. 3753 - 3756
(2014/09/16)
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- Homobivalent ligands of the atypical antipsychotic clozapine: Design, synthesis, and pharmacological evaluation
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To date all typical and atypical antipsychotics target the dopamine D 2 receptor. Clozapine represents the best-characterized atypical antipsychotic, although it displays only moderate (submicromolar) affinity for the dopamine D2 receptor. Herein, we present the design, synthesis, and pharmacological evaluation of three series of homobivalent ligands of clozapine, differing in the length and nature of the spacer and the point of attachment to the pharmacophore. Attachment of the spacer at the N4′ position of clozapine yielded a series of homobivalent ligands that displayed spacer-length-dependent gains in affinity and activity for the dopamine D 2 receptor. The 16 and 18 atom spacer bivalent ligands were the highlight compounds, displaying marked low nanomolar receptor binding affinity (1.41 and 1.35 nM, respectively) and functional activity (23 and 44 nM), which correspond to significant gains in affinity (75- and 79-fold) and activity (9- and 5-fold) relative to the original pharmacophore, clozapine. As such these ligands represent useful tools with which to investigate dopamine receptor dimerization and the atypical nature of clozapine.
- McRobb, Fiona M.,Crosby, Ian T.,Yuriev, Elizabeth,Lane, J. Robert,Capuano, Ben
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supporting information; experimental part
p. 1622 - 1634
(2012/04/17)
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- Synthesis of novel α,ω-type 1-glucosamide and 1-galactosamide bolaamphiphiles
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A new family of bolaamphiphiles in which two glucosylamine or galactosylamine moieties are linked via a β-N-glycosdic bond to an α,ω-dicarboxylic acid has been described. The 1-D-glucosamide and 1-D-galactosamide bolaamphiphiles were obtained in good yield by the condensation of the dicarboxylic acid dichloride with the corresponding 1-aldopyranosylamine.
- Masuda, Mitsutoshi,Shimizu, Toshimi
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p. 405 - 416
(2007/10/03)
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- Chemical switching of vesicle bilayer membrane disruption by bis(crown ether) bolaamphiphiles
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Bis(crown ether) bolaamphiphiles derived from 18-crown-6 dicarboxylic acid were prepared, and their ability to release vesicle encapsulated 5[6]- carboxyfluorescein was determined. Bolaamphiphiles with a linear central spacer are poor membrane disrupting agents except in the presence of alkaline earth metal cations or ethylenediammonium cation. Divalent ion enhancement of membrane disruption is cation selective and can be used to determine the apparent association constant of the bolaamphiphile crown ether with the added cation. The cis-isomer of a thioindigo bis(crown ether) bolaamphiphile is an active membrane disrupting agent, but the trans-isomer is significantly less active. In homogeneous solution, cis-to-trans thermal and photochemical isomerization is retarded by added alkaline earth metal salts, indicating that cooperative ditopic binding of the cations occurs despite the inherent flexibility of the bolaamphiphile. The membrane disruption mechanism occurs via U-shaped conformations of the bolaamphiphile. All available data indicate that divalent cations accelerate membrane disruption by stabilization of the U-shaped conformation via cooperative interaction of the crown ethers with the dication. Thus the membrane disruption process is switched 'on' by molecular recognition.
- Fyles,Zeng
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p. 8337 - 8345
(2007/10/03)
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- Synthesis and properties of a lipid bilirubin analog
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A new synthesis of dipyrrinone acids is described from the known dipyrrinone, 3-ethyl-2,7,9-trimethyl-(10H)-dipyrrin-1-one (11) with a free β-position. In six steps, 11 was converted to 5 with a C20 eicosanoic acid chain, and 5 was converted to
- Thyrann, Thomas,Lightner, David A.
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p. 447 - 460
(2007/10/03)
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- Design, synthesis, and activity of membrane-disrupting bolaphiles
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Four new classes of bolaphiles ("double-headed" single-chain surfactants) have been prepared, via condensation of an homologous series of linear saturated, olefinic, and acetylenic α,ω-dicarboxylic acids with hexaethylene glycol, and evaluated for their ability to induce the release of 5(6)-carboxyfluorescein (CF) entrapped within large unilamellar vesicles derived from 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC). Operationally, the membrane-disrupting activity of the bolaphiles has been found to vary by a factor of ca. 100, when the total number of carbon atoms which separate the carboxylate moieties range from 12 to 24; the most active bolaphile is approximately three times more active than Triton X-100. When the affinity of the bolaphiles toward POPC membranes is considered, the intrinsic membrane-disrupting activity varies by a factor of ca. 230. A "loop" model is proposed to account for the general trends in bolaphile activity that are observed, where the depth of loop penetration and loop width are presumed to be the key factors involved in determining membrane-disrupting activity. The potential utility of these surfactants as antimicrobial agents, and as anti-HIV agents in particular, is briefly discussed.
- Jayasuriya, Nimal,Bosak, Stanislav,Regen, Steven L.
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p. 5844 - 5850
(2007/10/02)
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