6203-18-5Relevant articles and documents
A Difluoroboron β-Diketonate Probe Shows turn-on Near-Infrared Fluorescence Specific for Tau Fibrils
Park, Kwang-Su,Kim, Mi Kyoung,Seo, Yujin,Ha, Taewoong,Yoo, Kyeongha,Hyeon, Seung Jae,Hwang, Yu Jin,Lee, Junghee,Ryu, Hoon,Choo, Hyunah,Chong, Youhoon
, p. 2124 - 2131 (2017)
Tau aggregation in neuronal cells has recently received significant attention as a robust predictor of the progression of Alzheimer's disease (AD) because of its proven correlation with the degree of cognitive impairment in AD patients. Accordingly, noninvasive imaging of tau aggregates has been highlighted as a promising diagnostic tool for AD. We have previously identified a tau-specific turn-on near-infrared fluorescent (NIRF) probe (1), and, in this study, structural modification was performed to optimize its physicochemical as well as fluorescence properties. Thus, a series of fluorescent dyes (2a-2j) composed of a variously substituted difluoroboron β-diketonate and an N,N-dimethylaniline moiety linked by a length-extendable π-bridge were prepared. Among those, isobutyl-substituted difluoroboron β-ketonate with a π-conjugated 1,4-butadienyl linker (2e) showed the most promising properties as a tau-specific NIRF probe. Compared with 1, the turn-on fluorescence of 2e was more specific to tau fibrils, and it showed 8.8- and 6.2-times higher tau-over-Aβ and tau-over-BSA specificity, respectively. Also, the fluorescence intensity of 2e upon binding to tau fibrils was substantially higher (~2.9 times) than that observed from 1. The mechanism for tau-specificity of 2e was investigated, which suggested that the molecular rotor-like property of 2e enables specific recognition of the microenvironment of tau aggregates to emit strong fluorescence. In transgenic cell lines stably expressing GFP-tagged tau proteins, 2e showed good colocalization with tau-GFP. Moreover, the fluorescence from 2e exhibited almost complete overlap with p-Tau antibody staining in the human AD brain tissue section. Collectively, these observations demonstrate the potential of 2e as a tau-specific fluorescent dye in both in vitro and ex vivo settings.
Benzothiazolium Derivative-Capped Silica Nanocomposites for β-Amyloid ImagingIn Vivo
Ma, Lijun,Yang, Shu,Ma, Yufan,Chen, Yuzhi,Wang, Zhenguo,James, Tony D.,Wang, Xuefei,Wang, Zhuo
, p. 12617 - 12627 (2021/09/30)
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.
Selective Rhodium-Catalyzed Hydroformylation of Terminal Arylalkynes and Conjugated Enynes to (Poly)enals Enabled by a π-Acceptor Biphosphoramidite Ligand
Zhao, Jiangui,Zheng, Xueli,Tao, Shaokun,Zhu, Yuxin,Yi, Jiwei,Tang, Songbai,Li, Ruixiang,Chen, Hua,Fu, Haiyan,Yuan, Maolin
supporting information, p. 6067 - 6072 (2021/08/16)
The hydroformylation of terminal arylalkynes and enynes offers a straightforward synthetic route to the valuable (poly)enals. However, the hydroformylation of terminal alkynes has remained a long-standing challenge. Herein, an efficient and selective Rh-catalyzed hydroformylation of terminal arylalkynes and conjugated enynes has been achieved by using a new stable biphosphoramidite ligand with strong π-acceptor capacity, which affords various important E-(poly)enals in good yields with excellent chemo- and regioselectivity at low temperatures and low syngas pressures.