19275-68-4Relevant articles and documents
An ESIPT Probe for the Ratiometric Imaging of Peroxynitrite Facilitated by Binding to Aβ-Aggregates
Sedgwick, Adam C.,Dou, Wei-Tao,Jiao, Jin-Biao,Wu, Luling,Williams, George T.,Jenkins, A. Toby A.,Bull, Steven D.,Sessler, Jonathan L.,He, Xiao-Peng,James, Tony D.
, p. 14267 - 14271 (2018)
A series of 3-hydroxyflavone (3-HF) ESIPT (excited-state intramolecular proton transfer) boronate-based fluorescent probes have been developed for the detection of peroxynitrite (ONOO-). The dyes are environmentally sensitive, and each probe exhibited a ratiometric response toward ONOO-in a micellar environment. The probes were used to image different aggregation states of amyloid-β (Aβ) in the presence of ONOO-. The3-HF-OMeprobe was found to produce a ratiometric response toward ONOO-when bound to Aβ aggregates, resulting in a novel host-guest ensemble, which adds insight into the development of other ESIPT-based probes for the simultaneous sensing of fibrous proteins/peptides and environmental ROS/RNS.
The three-component photoinitiating systems based on flavonol sulfonate and application in 3D printing
Bao, Binghui,Du, Yao,Hu, Tianyu,Wang, Tao,Xue, Tanlong,Ye, Yaoyao,You, Jian
, (2021/10/27)
Three-dimensional (3D) printed photocurable shape-shifting polymers based on a three-component photoinitiated system (PIS) (flavonol sulfonate/triethanolamine/iodonium salt) were studied. The flavonol sulfonate (3HF–F) with charge transfer ability and long-wavelength absorption was designed and prepared using the Algar–Flynn–Oyamada method which is an important component of the oxidation–reduction PIS initiating the polymerization of polyethylene glycol (600) diacrylate (PEGDA) under 405 nm LED. For light absorption (active absorber) and electron/proton transfer, the three-component PIS has high-function conversion, and short induction period during the photopolymerization of PEGDA. As the same time, 3HF–F could also undergo passive absorption to obtain high-resolution DLP 3D-printed polymers. The printed polymers could be reversibly modified by means of hydrophilic and thermal responses caused by the stimuli-responsiveness of the polymer chains to activate the shifting of shape.
Exploring 3-Benzyloxyflavones as new lead cholinesterase inhibitors: synthesis, structure–activity relationship and molecular modelling simulations
Mughal, Ehsan Ullah,Sadiq, Amina,Ayub, Momna,Naeem, Nafeesa,Javid, Asif,Sumrra, Sajjad Hussain,Zafar, Muhammad Naveed,Khan, Bilal Ahmad,Malik, Fouzia Perveen,Ahmed, Ishtiaq
, p. 6154 - 6167 (2020/08/10)
In this protocol, a series of 3-benzyloxyflavone derivatives have been designed, synthesized, characterized and investigated in?vitro as cholinesterase inhibitors. The findings showed that all the synthesized target compounds (1–10) are potent dual inhibitors of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes with varying IC50 values. In comparison, they are more active against AChE than BChE. Remarkably, amongst the series, the compound 2 was identified as the most active inhibitor of both AChE (IC50 = 0.05 ± 0.01 μM) and BChE (IC50 = 0.09 ± 0.02 μM) relative to the standard Donepezil (IC50 = 0.09 ± 0.01 for AChE and 0.13 ± 0.04 μM for BChE). Moreover, the derivatives 5 (IC50 = 0.07 ± 0.02 μM) and 10 (0.08 ± 0.02 μM) exhibited the highest selective inhibition against AChE as compared to the standard. Preliminary structure-activity relationship was established and thus found that cholinesterase inhibitory activities of these compounds are highly dependent on the nature and position of various substituents on Ring-B of the 3-Benzyloxyflavone scaffolds. In order to find out the nature of binding interactions of the compounds and active sites of the enzymes, molecular docking studies were carried out. (Figure presented.) HIGHLIGHTS 3-benzyloxyflavone analogues were designed, synthesized and characterized. The target molecules (1–10) were evaluated for their inhibitory potential against AChE and BChE inhibitory activities. Limited structure-activity relationship was developed based on the different substituent patterns on aryl part. Molecular docking studies were conducted to correlate the in?vitro results and to identify possible mode of interactions at the active pocket site of the enzyme. Communicated by Ramaswamy H. Sarma.
Synthesis of Flavonols via Pyrrolidine Catalysis: Origins of the Selectivity for Flavonol versus Aurone
Xiong, Wei,Wang, Xiaohong,Shen, Xianyan,Hu, Cuifang,Wang, Xin,Wang, Fei,Zhang, Guolin,Wang, Chun
supporting information, p. 13160 - 13176 (2020/11/23)
A novel synthetic method for flavonol from 2′-hydroxyl acetophenone and benzaldehyde promoted by pyrrolidine under an aerobic condition in water is established. This protocol was supported by efficient synthesis of 44 common examples and three natural products. The α, β-unsaturated iminium ion (enimine ion E) was proved to be the key intermediate in the reaction. H218O and 18O2 isotope tracking experiments demonstrated that both water and the aerobic atmosphere were necessary to ensure the transformation. The selectivity for flavonol or aurone was originated from solvent-triggered intermediates, which were determined by UV-visible spectra from isolated enimine. The phenol-iminium E-A is dominant in water and the ketoenamine intermediate E-B is prevalent in acetonitrile. In the presence of pyrrolidine and oxygen, E-A leads to flavonol through E-I, a zwitterionic-like phenoloxyl-iminium ion, following the key steps of cyclization and a [2 + 2] oxidation; E-B proceeds through path II, a radical process induced by photolysis of E-B with both pyrrolidine and oxygen, to afford aurone. Preliminary mechanistic studies are reported.
