Detection and Imaging of Aβ1-42 and Tau Fibrils by Redesigned Fluorescent X-34 Analogues was written by Zhang, Jun;Sandberg, Alexander;Konsmo, Audun;Wu, Xiongyu;Nystroem, Sofie;Nilsson, K. Peter R.;Konradsson, Peter;Le Vine, Harry III;Lindgren, Mikael;Hammarstroem, Per. And the article was included in Chemistry – A European Journal in 2018.SDS of cas: 148231-12-3 This article mentions the following:
The authors revisited the Congo red analog 2,5-bis(4′-hydroxy-3′-carboxy-styryl)benzene (X-34) to develop this highly fluorescent amyloid dye for imaging Alzheimer’s disease (AD) pathol. comprising Aβ and Tau fibrils. A selection of ligands with distinct optical properties were synthesized by replacing the central benzene unit of X-34, with other heterocyclic moieties. Full photophys. characterization was performed, including recording absorbance and fluorescence spectra, Stokes shift, quantum yield and fluorescence lifetimes. All ligands displayed high affinity towards recombinant amyloid fibrils of Aβ1-42 (13-300 nM Kd) and Tau (16-200 nM Kd) as well as selectivity towards the corresponding disease-associated protein aggregates in AD tissue. These ligands efficiently displaced X-34, but not Pittsburgh compound B (PiB) from recombinant Aβ1-42 amyloid fibrils, arguing for retained targeting of the Congo red type binding site. The authors foresee that the X-34 scaffold offers the possibility to develop novel high-affinity ligands for Aβ pathol. found in human AD brain in a different mode compared with PiB, potentially recognizing different polymorphs of Aβ fibrils. In the experiment, the researchers used many compounds, for example, 5,8-Dibromoquinoxaline (cas: 148231-12-3SDS of cas: 148231-12-3).
5,8-Dibromoquinoxaline (cas: 148231-12-3) belongs to pyrazine derivatives. Pyrazines are volatile compounds that are used in the cosmetic, food, flavor, and fragrance industries. Pyrazines are chemical compounds (technically called “methoxypyrazines”) found in grape skin and stems that are responsible for many “green” flavors in wine. Levels of pyrazines are dependent on viticultural practices, climate, and grape variety.SDS of cas: 148231-12-3