- Aged red wine pigments as a source of inspiration for organic synthesis - The cases of the color-stable pyranoflavylium and flavylium-(4→8)-flavan chromophores
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Two flavylium-based chromophores peculiar to aged red wine pigments are investigated from a synthetic viewpoint. The condensation between easy-to-prepare 5-hydroxy-4-methylflavylium salts and aldehydes, giving birth to color-stable pyranoflavylium pigments, further proves efficient and wide in scope. A set of some twenty structurally-related flavylium-based pigments has been prepared and structure:color relationships are discussed. Furthermore, the synthesis of the flavylium-(4→8)-flavan chromophore is achieved via a novel three-step sequence. The elaborated sequence starts with an iodine-magnesium exchange from an 8-iodinated flavan, thus generating a magnesiated species that then smoothly reacts with a flavone to furnish an adduct, that finally leads to the expected chromophore via dehydration.
- Chassaing, Stefan,Isorez-Mahler, Géraldine,Kueny-Stotz, Marie,Brouillard, Raymond
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p. 3066 - 3078
(2015/05/04)
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- Design, synthesis, acetylcholinesterase inhibition and larvicidal activity of girgensohnine analogs on Aedes aegypti, vector of dengue fever
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Girgensohnine alkaloid was used as a natural model in the design and generation of new alkaloid-like α-aminonitrile series that was completed by the use of SSA-catalyzed Strecker reaction between commercial and inexpensive substituted benzaldehydes, piperidine (pyrrolidine, morpholine and N-methylpiperazine) and acetone cyanohydrin. Calculated ADMETox parameters of the designed analogs revealed their good pharmacokinetic profiles indicating lipophilic characteristics. In vitro AChE enzyme test showed that obtained α-aminonitriles could be considered as AChEIs with micromolar IC 50 values ranging from 42.0 to 478.0 μM (10.3-124.0 μg/mL). Among this series, the best AChE inhibitor was the pyrrolidine α-aminonitrile 3 (IC50 = 42 μM), followed by the piperidine α-aminonitriles 2 and 6 (IC50 = 45 μM and IC50 = 51 μM, respectively), and the compound 7 (IC50 = 51 μM). In vivo insecticidal activity of more active AChEIs against Aedes aegypti larvae was also performed showing a good larvicidal activity at concentrations less than 140 ppm, highlighting products 2 and 7 that could serve as lead compounds to develop new potent and selective insecticides.
- Carre?o Otero, Aurora L.,Vargas Méndez, Leonor Y.,Duque L., Jonny E.,Kouznetsov, Vladimir V.
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p. 392 - 400
(2014/04/17)
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- An asymmetric synthesis of (-)-deoxypodophyllotoxin
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A Diels-Alder cycloaddition between the fumarate of methyl (S)-mandelate (22) and α-hydroxy-α-aryl-o-quinodimethane 21 produces an endo cycloadduct (23) in 58% yield. The preparation of the precursor to o-quinodimethane 21 and the conversion of cycloadduct 23 to optically pure (-)-deoxypodophyllotoxin (1) is described.
- Bogucki,Charlton
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p. 588 - 593
(2007/10/02)
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- Substituted phenyl-1,2,4-triazolo[2,3-b]pyridazin-3(2H)ones as anti-asthma agents
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Substituted phenyl-1,2,4-triazolo[4,3-b]pyridazin-3(2H)-ones, useful as anti-asthma agents.
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