1207-72-3Relevant articles and documents
Design and synthesis of new theranostic agents for near-infrared imaging of β-amyloid plaques and inhibition of β-amyloid aggregation in Alzheimer's disease
Dao, Pascal,Ye, Feifei,Du, Zhi Yun,Chen, Qian,Zhang, Kun,Dong, Chang Zhi,Meunier, Bernard,Chen, Huixiong
, p. 130 - 140 (2017)
The presence of amyloid plaques predisposes clinical symptoms of cognitive impairment, which occurs much earlier than other clinical symptoms and plays a crucial role in the neuropathology of AD. Thus, developing probes for Aβ species imaging could be used for early diagnosis of AD, and blocking the initial steps of Aβ aggregation with small molecules has emerged as a valid disease-modifying therapy for Aβ. Herein, we report the design, synthesis and evaluation of a series of new theranostic agents, which can simultaneously perform near infra-red imaging of Aβ plaques, prevent self-aggregation of Aβ monomer, disaggregate preformed Aβ fibrils and play a protective effect on the toxicity of human neuroblastoma cells (SHSY5Y) induced by Aβ1–42. Most of these probes displayed maximum emission in PBS (>650 nm), which falls in the good range for NIRF probes. Importantly, these probes are found to have a high binding affinity toward Aβ aggregates, to exhibit a large fluorescence enhancement upon interaction with Aβ aggregates accompanied by a blueshift in the emission spectra of 20–40 nm and to show an excellent targeting ability for Aβ plaques in slices of brain and eye containing retina tissue from double transgenic mice. These molecules show a promising potential as theranostic agents for the diagnosis and therapy of AD.
Selective oxidaton methods for preparation of N-alkylphenothiazine sulfoxides and sulfones
Tosa, Monica,Paizs, Csaba,Majdik, Cornelia,Poppe, Laszlo,Kolonits, Pal,Silberg, Ioan A.,Novak, Lajos,Irimie, Florin-Dan
, p. 277 - 282 (2001)
Efficient and selective oxidation methods for preparation of N-alkylphenothiazine sulfoxides 2a-h and sulfones 3a-h starting from N-alkylphenothiazines 1a-h are described.
Trans -A2B-corrole bearing 2,3-di(2-pyridyl)quinoxaline (DPQ)/phenothiazine moieties: Synthesis, characterization, electrochemistry and photophysics
Kandhadi, Jaipal,Yan, Wei-Cong,Cheng, Fan,Wang, Hui,Liu, Hai-Yang
, p. 9987 - 9999 (2018)
Two novel donor-acceptor systems (F10C-PTZ and F10C-DPQ) were designed and synthesized, in which corrole is an acceptor and either phenothiazine (PTZ) or 2,3-di(2-pyridyl)quinoxaline (DPQ) is an energy/electron donor. These dyads represent some of the few examples of photostable corrole dyads reported in the literature, but the first example of 2,3-di(2-pyridyl)quinoxaline (DPQ) containing meso substituted corrole (F10C-DPQ) also directly connected PTZ to the meso position of corrole (F10C-PTZ). Both the dyads were characterized by high-resolution mass spectrometry (HR-MS), NMR (1H, 13C, 19F) spectroscopy, UV-Vis spectroscopy, steady state fluorescence, time-resolved fluorescence (TCSPC, MCP-PMT), electrochemical methods (CV, DPV) as well as theoretical calculations (DFT, TD-DFT). From absorption and electrochemical studies it is evident that there exist minimum π-π interactions between two hetero chromophoric units in the dyads. The steady state fluorescence studies indicate that an efficient quenching of emission corresponding to the PTZ unit in the F10C-PTZ dyad is attributed to the singlet-singlet energy transfer from PTZ to corrole. In addition to the spectral overlap, excitation spectra provided additional evidence for intramolecular energy transfer. Whereas in the F10C-DPQ dyad, a reductive electron transfer, from the ground state of DPQ to the excited state of corrole, was observed. The negative free energy (ΔG) for charge separation, anodic shift of reduction potential of corrole and the frontier molecular orbital (LUMO) location provide addition support for charge transfer. The solvent dependent rate of an energy and electron transfer was discussed.
A turn-on fluorescent BOPHY probe for Cu2+ ion detection
He, Chunhua,Zhou, Huipeng,Yang, Na,Niu, Niu,Hussain, Ejaz,Li, Yongxin,Yu, Cong
, p. 2520 - 2525 (2018)
A new fluorine-boron compound BOPHY-PTZ was designed and synthesized. The fluorescent dye was used as a highly sensitive probe for Cu2+ ion detection. The mechanism of detection involved Cu2+ ion oxidation of the phenothiazine (PTZ) moiety and blocked the intramolecular charge transfer (ICT) process from the electron-donating PTZ moiety to the electron-accepting BOPHY moiety. BOPHY-PTZ showed a weak fluorescence in solution. However, it displayed a strong fluorescence signal enhancement upon the addition of Cu2+ ions, and 1.0 nM concentration of Cu2+ can be clearly detected. The assay is simple, sensitive and convenient, and it exhibits excellent selectivity for Cu2+ ions over the other metal ions. The BOPHY-PTZ probe could be used for Cu2+ ion detection in practical samples and for environmental monitoring related applications.
Photoinduced Electron Transfer from N-Alkylphenothiazines to Interface Water of Sodium Dodecyl Sulfate Micelles as a Function of Poly(ethylene oxide) Interaction with the Interface
Kang, Young Soo,Kevan, Larry
, p. 2478 - 2481 (1994)
Photoinduced electron transfer from N-alkylphenothiazines (PCn, n = 1, 3, 6, 12, and 16) solubilized in sodium dodecyl sulfate (SDS) micelle interacting with poly(ethylene oxide) (PEO) to interface D2O as an electron acceptor is studied with electron spin resonance (ESR) and electron spin echo modulation.The photoproduced radicals are identified as the N-alkylphenothiazine cation radical and the surfactant alkyl chain radical of SDS.The total photoyield decreased from PC1 to PC3 and then increased to PC16.The photoyields increased monotonically with increasing PEO concentration.The photoyields are correlated with the deuterium modulation depth of PCn+ with D2O at the micelle interface as a function of the alkyl chain length of PCn and the concentration of PEO since the modulation depth measures relative changes in the interaction distance between the phenothiazine moiety and interface D2O.The photoyield and deuterium modulation depth trends show a good correlation which indicates that the electron transfer from phenothiazine moiety to interface water is mainly controlled by the distance between them, which is controllably varied by the alkyl chain length of phenothiazine and the intercalation of PEO into the interface region of the SDS micellar headgroup.
Phenothiazine-oxadiazole push-pull fluorophores: Combining high quantum efficiency, excellent electrochemical stability and facile functionalization
Wong, Michael Y.,Leung, Louis M.
, p. 542 - 549 (2017)
A series of five novel sky-blue to green emitting push-pull fluorophores based on phenothiazine donor and 1,3,4-oxadiazole acceptor were synthesized and characterized. Their doped thin films (5 wt% in PMMA) showed high quantum efficiencies (ФPL) from 0.63 to 0.77. These fluorophores also underwent remarkably reversible oxidations and reductions suggesting their excellent electrochemical stability. Facile tuning of photophysical, thermal and electrochemical properties of the fluorophores could be achieved by optimizing the functional group attached to the 1,3,4-oxadiazole moiety. Finally, we propose that further functionalization of these fluorophores can be easily achieved and as a proof of concept the synthesis of a vinyl polymer derivative Poly(PO-Tol) was demonstrated.
Structure-reactivity relationship of probes based on the H2S-mediated reductive cleavage of the CC bond
Tan, Jingyun,Wang, Chunfei,Zhang, Xuanjun
, p. 11667 - 11677 (2020)
Recently, we discovered the H2S-mediated reductive cleavage of the CC bond, and applied this reaction to design probes for the detection of H2S. To extensively elucidate the structure-reactivity relationship, our current work further investigated the effect of substitutes that connected to the CC bond on the H2S-mediated reductive cleavage, wherein different kinds of electron-withdrawing groups (such as pyridine, bipyridine, terpyridine) and electron donating groups (such as carbazole, N,N-dimethylaniline and phenothiazine) were conjugated to the CC bond of interest. Experimental results and DFT calculations showed that the strength of the electron-donating and withdrawing substitutes could significantly affect the reductive cleavage of the CC bond. Unexpectedly, the reductive cleavage was not influenced by the change of the C(2) and C(3) positions in phenothiazine. On this basis, two probes (NPTZ-P1 and NPTZ-P2) with a C(3)-substituted phenothiazine were thus developed and successfully applied for sensing exogenous H2S in living HeLa cells, which implied their potential in bioimaging. This study provides further understanding on the structure-reactivity relationship of the H2S-mediated reductive cleavage of the CC bond, and is also valuable for exploring new reactions of the CC bond in organic synthesis. This journal is
Corrole-phenothiazine and porphyrin-phenothiazine dyads connected at β-position: Synthesis and photophysical properties
Kandhadi, Jaipal,Cheng, Fan,Wang, Hua-Hua,Ali, Atif,Wang, Li-Li,Wang, Hui,Liu, Hai-Yang
, p. 368 - 378 (2017)
Two novel donor-acceptor dyads, in which phenothiazine (PTZ) connected at β-pyrrolic position of either freebase corrole (TPC) or freebase porphyrin (TPP) via vinylic spacer have been synthesized. Both the dyads were characterized by ESI-MS, IR, 1H NMR (1D and 2D 1H-1H COSY and J-Resolved), UV–Vis, Study state Fluorescence, Time-resolved fluorescence (Time-correlated single photon counting (TCSPC), Streak Camera) as well as electrochemical methods. In the absorption spectra of the dyads, both Soret and Q-bands were red shifted by 8–20?nm indicating weak electronic communication between the two chromophores. However, the fluorescence emission from the PTZ of the dyad was efficiently quenched (96–99%) as compared to pristine PTZ where the dyad was excited at 310?nm, which is attributed to singlet-singlet excited energy transfer. Fluorescence emission from porphyrin part of the TPP-PTZ dyad also quenched when excite the dyad at 420?nm, which is ascribed to photoinduced electron transfer from ground state of PTZ to excited state of porphyrin. In contrast, when excite the corrole at 420?nm in TPC-PTZ dyad, we found there are no significant changes in photophysical properties. In both the cases the solvent dependence of the rate of energy and electron transfer was observed.
Cation radicals of N-substituted phenothiazines
Tomilin,Konovalova,Yuzhalkin,Ryabkina,Sanaeva
, p. 365 - 370 (1996)
The reaction of N-substituted phenothiazines with certain acceptors (halogenated solvents CHCl3, CH2Br2, CCl4, o-chloranil, AlCl3, SnCl4, concentrated H2SO4, concentrated HNO3 in HClO4) has been studied by EPR spectroscopy. The hyperfine structure in the EPR spectra of the cation radicals is analyzed. To interpret the EPR spectra obtained in terms of the MNDO-PM3 method we carried out a calculation of the electronic structure of phenothiazine cation radicals containing N-CH3 and N-CH2R substituents. In these radical systems, there are significant steric hindrances to conformational rotation of the CH2 substituent around the N-C bond leading to a conformation with magnetically non-equivalent protons in the methylene group. 1996 Plenum Publishing Corporation.
MECHANISMS OF LIGHT-INITIATED REDOX REACTIONS OF COPPER(II)-CYCLIC POLYAMINE SURFACTANT ASSEMBLIES.
Moroi
, p. 3265 - 3270 (1981)
Photo-induced reduction of Cu**2** plus ion by organic electron donors was studied, main attention being paid to the decay kinetics of the cathionized donor using two kinds of Cu**2** plus ions; one is free to move around the micellar surface of copper(II) dodecyl sulfate(Cu(DS)//2), the other being fixed in a cyclic polyamine, Cu**2** plus complex of 2-tetradecyl-1,4,7,10-tetraazacyclododecane (CPA). Sodium 12-(10-phenothiazinyl)dodecanesulfonate (PTHDS) functions quite similarly to N-methylphenothiazine (MPTH) in an electron transfer reaction in Cu(DS)//2 micelles, and the reduced Cu** plus is ejected from the micelles. In the MPTH-CPA system, MPTH** plus is completely ejected from the host micelle in the CPA micellar system. In consequence, the decay of the cationized donor obeys a second-order rate law, while the rate constant becomes much less.
Bis(pentafluorophenyl)phenothiazylborane-an intramolecular frustrated Lewis pair catalyst for stannane dehydrocoupling
Bentley, Jordan N.,Caputo, Christopher B.,Pradhan, Ekadashi,Zeng, Tao
supporting information, p. 16054 - 16058 (2020/12/03)
We synthesized a novel Lewis acidic aminoborane containing a phenothiazyl substituent and demonstrated its potential to catalytically promote the dehydrocoupling of tin hydrides. The observed reactivity would imply a homolytic frustrated Lewis pair type mechanism, however computational analysis suggests a heterolytic mechanism for this reaction. This result represents one of the first frustrated Lewis pair systems to dehydrocouple stannanes in a heterolytic fashion.
