- Novel cyclopentadienyl tricarbonyl complexes of 99mTc mimicking chalcone as potential single-photon emission computed tomography imaging probes for β-amyloid plaques in brain
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Rhenium and technetium-99m cyclopentadienyl tricarbonyl complexes mimicking the chalcone structure were prepared. These complexes were proved to have affinity to β-amyloid (Aβ) in fluorescent staining on brain sections of Alzheimer's Disease (AD) patient and binding assay using Aβ 1-42 aggregates, with Ki values ranging from 899 to 108 nM as the extension of conjugated π system. In vitro autoradiograpy on sections of transgenic mouse brain confirmed the affinity of [99mTc]5 (K i = 108 nM). In biodistribution, all compounds showed good initial uptakes into the brain and fast blood clearance, while the decreasing of initial brain uptakes correspond to increasing of conjugation length, from 4.10 ± 0.38% ID/g ([99mTc]3) to 1.11 ± 0.34% ID/g ([ 99mTc]5). These small technetium-99m complexes (a promising 99mTc-labeled agent for imaging Aβ plaques in the brain may be feasible.
- Li, Zijing,Cui, Mengchao,Dai, Jiapei,Wang, Xuedan,Yu, Pingrong,Yang, Yanping,Jia, Jianhua,Fu, Hualong,Ono, Masahiro,Jia, Hongmei,Saji, Hideo,Liu, Boli
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- A convenient synthesis of conjugated ω-arylpolyenals via Wittig reaction with (1,3-dioxan-2-yl-methyl)triphenylphosphonium bromide/sodium hydride
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Commercially available reagent, (1,3-dioxan-2-yl-methyl)triphenylphosphonium bromide, sodium hydride and a catalytic amount of 18-crown-6 has proven efficient system for vinylic extension of ω-arylpolyenals.
- Plazuk, Damian,Janowska, Izabela,Klys, Arkadiusz,Hameed, Asia,Zakrzewski, Janusz
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- Benzothiazolium Derivative-Capped Silica Nanocomposites for β-Amyloid ImagingIn Vivo
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Alzheimer’s disease (AD) is a neurodegenerative disease, and β-amyloid (Aβ) is believed to be a causative factor in AD pathology. The abnormal deposition of Aβ is believed to be responsible for progression of AD. In order to facilitate the imaging of Aβin vivo, suitable probe molecules with a near-infrared emission wavelength that can penetrate the blood-brain barrier (BBB) were utilized. The commercial fluorescent probe thioflavin-T (ThT) is used to image Aβ; however, because of its short emission wavelength and poor BBB penetration, ThT can only be usedin vitro. With this research, based on ThT, we design three fluorescent probes (SZIs) having a longer emission wavelength in order to image Aβ aggregates. SZIs with different numbers of double bonds respond to Aβ aggregates. The SZIs have a structure similar to ThT, and as such, the SZIs are also unable to penetrate the BBB. To deal with the problem, we develop nanocomposites (MSN-Lf@SZIs) to deliver SZIs into the brain of AD mouse and image Aβ successfully. These new nanocomposites are able to deliver the dyes into the brain and facilitate Aβ imagingin vivo.
- Ma, Lijun,Yang, Shu,Ma, Yufan,Chen, Yuzhi,Wang, Zhenguo,James, Tony D.,Wang, Xuefei,Wang, Zhuo
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p. 12617 - 12627
(2021/09/30)
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- Synthesis, structure, linear and nonlinear properties of tricyanofuran–terminated merocyanine dyes
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Structural and spectroscopic characteristics of merocyanine dyes are important because of their potential applications in optoelectronics and sensors. Herein we report synthesis, X-ray diffraction characterization of crystal structure, spectroscopic and NMR studies of four merocyanine dyes which, according to their strong donor-acceptor structure, exhibit a second order polarizability (β). Crystallographic studies demonstrated an almost planar structure of all molecules and indicated the occurrence of conformational changes in π-conjugated bridge between donor and acceptor. For three homologues similar packing modes, defined mostly by week C[sbnd]H?N interactions, were found in crystals. Bond length alternation (BLA) values have been evaluated using crystallographic and NMR data and have shown a correlation to their nonlinear optical activity. Second order polarizabilities for all compounds were measured using hyper Rayleigh scattering (HRS) in solution. It was found that the merocyanines studied exhibit very large second order polarizabilities (up to 4.1 10?27 esu), making them potentially useful for materials for second harmonic generation (SHG). Unfortunately, they do not demonstrate acentric packing of chromophores, which is required for SHG in the crystalline state, but may show promise for other applications such as poled polymer blends or for SHG sensing in biological environments.
- Tillotson, John P.,Bogdanov, Georgii,Jucov, Evgheni V.,Khrustalev, Victor N.,Rigin, Sergei,Hales, Joel M.,Perry, Joseph W.,Timofeeva, Tatiana V.
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p. 146 - 154
(2019/04/26)
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- Novel D-A-D based near-infrared probes for the detection of β-amyloid and Tau fibrils in Alzheimer's disease
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Novel D-π-A-π-D probes were investigated for the detection of Aβ plaques and NFTs. The probes displayed remarkable optical properties, and DADNIR-2 possessed high affinity towards Tau and Aβ aggregates (Kd = 0.41 nM and 1.04 nM, respectively) with certain selectivity. DADNIR-2 could penetrate the BBB and label Aβ plaques in vivo.
- Li, Yuying,Wang, Kan,Zhou, Kaixiang,Guo, Wentao,Dai, Bin,Liang, Yi,Dai, Jiapei,Cui, Mengchao
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supporting information
p. 8717 - 8720
(2018/08/09)
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- Structure-activity relationships of radioiodinated diphenyl derivatives with different conjugated double bonds as ligands for α-synuclein aggregates
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It is generally recognized that aggregates of α-synuclein (α-syn) in the brain are closely associated with the pathogenesis of Parkinson's disease (PD). Therefore, the development of in vivo imaging probes targeting α-syn aggregates is currently expected.
- Ono, Masahiro,Doi, Yuki,Watanabe, Hiroyuki,Ihara, Masafumi,Ozaki, Akihiko,Saji, Hideo
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p. 44305 - 44312
(2016/06/09)
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- The synthesis and evaluation of near-infrared probes with barbituric acid acceptors for in vivo detection of amyloid plaques
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A new array of near-infrared probes containing barbituric acid acceptors has been developed as Aβ imaging agents. These probes displayed long-emission wavelengths and large Stokes shifts, as well as high affinities for Aβ aggregates. In vivo and ex vivo studies demonstrated that BBTOM-3 could intensely label Aβ plaques in the brains of transgenic mice.
- Zhou, Kaixiang,Fu, Hualong,Feng, Liang,Cui, Mengchao,Dai, Jiapei,Liu, Boli
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supporting information
p. 11665 - 11668
(2015/07/15)
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- Computer aided benzothiazole derivatives. Synthesis, structure and biological study of new push-pull conjugated benzothiazolium salts
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As the conjugation is assumed to enhance the biological activity of push-pull type benzothiazolium salts, new compounds with extended conjugated bridge between benzothiazolium and phenyl ring were designed and synthesized. The compounds have been tested against the model microorganism Euglena gracilis as well as 6 microorganisms including Gram-positive and Gram-negative bacteria , a yeast and a mould. In accordance with predictions, the prepared compounds showed enhanced activity against Euglena and Gram-positive bacteria and some of them also interesting fungicidal and fungistatic activity.
- Buffa,Zahradnik,Foltinova
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p. 331 - 336
(2007/10/03)
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- Exclusive γ-regio functionalization of crotonaldehyde using γ-trimethylsilyl crotonaldimine. Application to the one pot synthesis of conjugated dienals
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Cesium fluoride mediated reaction of γ-trimethylsilyl N-tert-butyl crotonaldimine 9 with a wide range of aldehydes takes place in DMSO at room temperature and affords exclusive γ-regio functionalized products. Heating (rt to 100°C) the δ-silyloxy imines 11 thus obtained leads, after very mild hydrolysis of the tert-butylimine function, to the conjugated dienals 14 in good yields and with excellent (E,E)-selectivities.
- Bellassoued,Salemkour
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p. 4607 - 4624
(2007/10/03)
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- A new and easy route to (2E,4E)-dienals by four-carbon homologation of aldehydes
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A new synthetic method of (2E,4E)-dienals by four-carbon homologation of aldehydes is described. γ-trimethylsilyl crotonaldimine 2 , easily generated from N-ter-butyl-crotonaldimine 1, LDA and ClSiMe3, reacts with aldehydes in the presence of catalytic CsF in DMSO at rt → 100°C to afford homologous aldehydes 3 in good yields and with excellent (E,E)-selectivities.
- Bellassoued, Moncef,Salemkour, Malika
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p. 5281 - 5284
(2007/10/02)
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- A Simple and Highly Stereoselective Route to E-α,β-Unsaturated Aldehydes
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Zinc bromide mediated reaction of α,α-bis(trimethylsilyl)-tert-butylacetaldimine (3) with a wide range of aldehydes takes place under mild conditions and affords the corresponding α,β-unsaturated aldehydes in good yields and with high E stereoselectivity (>98percent).This procedure is successfully applied to the preparation of intermediates for retinoid and natural product synthesis.
- Bellassoued, Moncef,Majidi, Assieh
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p. 2517 - 2522
(2007/10/02)
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- PREPARATION OF CONJUGATED AROMATIC POLYENALS BY WITTIG OXOPROPENYLATION
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Heteroaromatic, or aromatic polyenals containing either electron-donating or withdrawing substituents can now be prepared easily in excellent yield by Wittig oxopropenylation with 1,3-dioxan-2-ylmethyltributyl phosphorane
- Spangler, Charles W.,McCoy, Ray K.
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- 5-(p-Dimethylaminophenyl)-2,4-pentadienal as an Analytical Reagent: A Simple Preparation of the Reagent and Its Application to the Colorimetric Determination of Primary Aromatic Amines
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5-(p-Dimethylaminophenyl)-2,4-pentadienal (DAPDA) was conveniently prepared from p-dimethylaminobenzaldehyde by using readily available 4-(tert-butylthio)-3-buten-2-one as the chain lengthening agent.It has been shown that DAPDA is a useful reagent for de
- Nakatsuji, Shin'Ichi,Nakano, Rie,Kawano, Mie,Nakashima, Kenichiro,Akiyama, Shuzo
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p. 2467 - 2473
(2007/10/02)
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