14919-49-4Relevant articles and documents
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Tyukavkina,Pogodaeva
, (1971)
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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.
Phototransformations of some 3-cyclohexenyloxychromenones: Synthesis of Spirocyclic compounds
Khanna, Radhika,Dalal, Aarti,Berar, Urmila,Singh, Sandeep,Kamboj, Ramesh C.
, p. 668 - 673 (2019/01/05)
The phototransformation of the 3-cyclohexenyloxychromenones by irradiation with a pyrex-filtered light from a 125 W Hg vapor lamp under an inert atmosphere into the spirocyclic fused xanthenones was described. The efficacy of the protocol depended upon th
Exploration of synthetic antioxidant flavonoid analogs as acetylcholinesterase inhibitors: an approach towards finding their quantitative structure–activity relationship
Karmakar, Abhijit,Ambure, Pravin,Mallick, Tamanna,Das, Sreeparna,Roy, Kunal,Begum, Naznin Ara
, p. 723 - 741 (2019/04/17)
The binding interactions between acetylcholinesterase (AChE) and a series of antioxidant flavonoid analogs were studied by fluorescence spectroscopic assay. The present study incorporated different classes of naturally occurring and synthetic flavonoid compounds like flavones, isoflavones, and chalcones as well as a few standard antioxidants. The AChE inhibitory (AChEI) activity of these compounds was further analyzed using in silico techniques, namely pharmacophore mapping, quantitative structure–activity relationship (QSAR) analysis, and molecular docking studies. We have also compared the AChE inhibitory and radical scavenging antioxidant activities of these compounds. Both the AChE inhibitory and antioxidant activities of these compounds were found to be highly dependent on their structural patterns. However, it was observed that, in general, flavones are comparatively better AChE inhibitors as well as antioxidants compared to chalcones. [Figure not available: see fulltext.].
