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# Organic Chemistry # Solid-state fluorescence of zwitterionic imidazolium pyridinolates bearing long alkyl chains: Control of emission properties based on variation of lamellar alignment Tetrahedron Available online 26 August 2017 DOI:10.1016/j.tet.2017.08.045 Atsushi Yoshida, Masahiro Ikeshita,Naruyoshi Komiya,Takeshi Naota Abstract:Herein, the control of the crystalline-state fluorescence of zwitterionic imidazolium 2-pyridin-3-olate 1 bearing linear alkyl chains via morphological variations is described, along with a mechanistic rationale. Crystals of 1a–e prepared from CH3CN exhibited intense blue fluorescence under UV irradiation at 298 K, whereas crystals of 1e prepared from i-PrOH/Et2O were less emissive under the same measurement conditions. Temperature-dependent emission spectra showed that emissive crystals of 1a–eexperienced minimal emission decay with increasing temperature, whereas crystalline 1e, having a different polymorphism, was highly heat-quenchable. Single-crystal XRD established that less emissive, heat-quenchable crystal 1e had a lamellar structure supported by consecutive face-to-face arrangement with π-stacking interactions between imidazolium and pyridinolate moieties, whereas highly emissive, heat-resistant crystals 1dand 1e had a face-to-edge lamellar structure with CH-π interactions between the heteroaromatic rings. Link to CBG： http://www./news/art?id=6527 Link to the article： http://www./science/article/pii/S0040402017308852 # Organic Chemistry # Inverse thermoresponse of a water-soluble helicene oligomer in aqueous-organic mixed solvent systemsTetrahedron Available online 26 August 2017 DOI:10.1016/j.tet.2017.08.046 Nozomi Saito, Higashi Kobayashi, Masahiko Yamaguchi Abstract:A water-soluble ethynylhelicene (M)-tetramer with TEG groups exhibited the inverse thermoresponse in water/triethylamine/acetone, in which heating induced the formation of double helix and cooling dissociation. In this study, we examined the solvent effect with regard to water content at temperatures between 5 and 40 °C, and showed that the inverse thermoresponse occurred in different aqueous solution systems. In acetone, the oligomer exhibited the ordinary thermoresponse: Cooling induced the formation of double helix and heating dissociation. The increase in water content to approximately 10% caused the switch to the inverse thermoresponse. Further increase inhibited the association, and did not induce the thermoresponse. When the water content was increased to approximately 50%, the inverse thermoresponse appeared as observed previously study. Two types of inverse thermoresponses, termed type I and II, appeared at high and low water contents, respectively. Link to CBG： http://www./news/art?id=6525 Link to the article： http://www./science/article/pii/S0040402017308864 # Medicinal Chemistry # From dual binding site acetylcholinesterase inhibitors to allosteric modulators: A new avenue for disease-modifying drugs in Alzheimer's disease European Journal of Medicinal Chemistry Available online 26 August 2017 DOI:10.1016/j.ejmech.2017.08.051 Talita P.C. Chierritoa, Susimaire P. Mantoania, Carlos Rocab, Carlos Requenab, Victor Sebastianb, Willian O. Castilloc, Natalia C.S. Moreirac, Concepción Péreze, Elza T. Sakamoto-Hojoc, d, Catarina S. Takahashi Abstract:The lack of an effective treatment for Alzheimer’ disease (AD), an increasing prevalence and severe neurodegenerative pathology, boost medicinal chemists to look for new drugs. Currently, only acethylcholinesterase (AChE) inhibitors and glutamate antagonist have been approved to the palliative treatment of AD. Although they have a short-term symptomatic benefits, their clinical use have revealed important non-cholinergic functions for AChE such its chaperone role in beta-amyloid toxicity. We propose here the design, synthesis and evaluation of non-toxic dual binding site AChEIs by hybridization of indanone and quinoline heterocyclic scaffolds. Unexpectely, we have found a potent allosteric modulator of AChE able to target cholinergic and non-cholinergic functions by fixing a specific AChE conformation, confirmed by STD-NMR and molecular modeling studies. Furthermore the promising biological data obtained on human neuroblastoma SH-SY5Y cell assays for the new allosteric hybrid 14, led us to propose it as a valuable pharmacological tool for the study of non-cholinergic functions of AChE, and as a new important lead for novel disease modifying agents against AD. Link to CBG： http://www./news/art?id=6528 Link to the article： http://www./science/article/pii/S0223523417306621 了解更多最全、最新论文快讯 登录CBG官网（www.） 下载ChemBeanGo APP CBG资讯 ∣知识就是力量 |
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