Die Konstitution des Kellins (aus Ammi visnaga) (I. Mitteil. über natürliche Chromone)

Späth, Ernst; Gruber, Werner

doi:10.1002/cber.19380710118

Cited by 76 publications

(20 citation statements)

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“…Chemistry α,β-Unsaturated carbonyl compounds 2a, 42) b, 43) c, e 44) and the new 2d were synthesized by reacting 1-(6-hydroxy-4-methoxybenzofuran-5-yl) ethanone 1 45) with the appropriate aromatic aldehydes in presence of sodium hydroxide by the conventional Claisen-Schmidt condensation.…”

Section: Resultsmentioning

confidence: 99%

“…Compounds 1, 45) 2a, 42) b, 43) c, e, 44) 3a, b, 4a, b, 28) 7a and b 43) were prepared according to reported procedures. General Procedure for Synthesis of 1-(6-Hydroxy-4-methoxybenzofuran-5-yl)-3-((un)substituted)phenylprop-2-en-1-one (2a-e) The warmed solution of 5-acetyl-4-methoxybenzofuran-6-ol 1 (1.9 g, 10 mmol) and the appropriate aromatic aldehyde (11 mmol) in ethanol (20 mL) was treated with 30% sodium hydroxide solution (5 mL) and was left for 48 h at room temperature.…”

Section: −1mentioning

confidence: 99%

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Benzofuran–Morpholinomethyl–Pyrazoline Hybrids as a New Class of Vasorelaxant Agents: Synthesis and Quantitative Structure–Activity Relationship Study

et al. 2014

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The benzofuran-morpholinomethyl-pyrazoline hybrids 4a-e, 5a-e and 6a-j were synthesized via reaction of α,β-unsaturated carbonyl compounds 3a-e with hydrazine hydrate, semicarbazide or thiosemicarbazide. Applying the Mannich reaction to 5-(5-aryl-4,5-dihydro-1H-pyrazol-3-yl)-4-methoxybenzofuran-6-ols 7a-e with morpholine hydrochloride and paraformaldehyde afforded positional isomeric 7-morpholinomethyl derivatives 4a-e and N-morpholinomethyl derivatives 8a-e. All the synthesized compounds showed significant vasodilatation properties in isolated thoracic aortic rings of rats precontracted using the standard norepinephrine hydrochloride technique. Compounds 3d, 3e, 5a-c, 6b, 6c, 6f, 6h and 6i exhibited activity (IC 50 0.3185-0.4577 mM) superior to that of prazocin (IC 50 0.487 mM), while 5d, 6j and 8c showed comparable activity (IC 50 0.4789-0.4951 mM). The quantitative structure-activity relationship study revealed a correlation between the observed vasorelaxant activities of the newly synthesized compounds and their different physicochemical parameters, especially solubility, in addition to structure connectivity and energetic quantities calculated from stored three dimensional (3D) conformations. Absorption, distribution, metabolism and elimination (ADME) evaluation showed good agreement with the biological results obtained.

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Section: Resultsmentioning

confidence: 99%

Section: −1mentioning

confidence: 99%

Benzofuran–Morpholinomethyl–Pyrazoline Hybrids as a New Class of Vasorelaxant Agents: Synthesis and Quantitative Structure–Activity Relationship Study

et al. 2014

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“…Khellinone 1 and visnaginone 2 were obtained by the method of Spaeth and Gruber [30,31], i.e., by the ring-opening reactions of khellin and visnagin in the alkaline solution. Single crystals of 1 and 2 suitable for an X-ray diffraction were prepared by a slow evaporation of the solvent from an ethanolic solution at room temperature.…”

Section: Synthesis Of Visnaginone and Khellinonementioning

confidence: 99%

Derivatives of benzo[b]furan. Part I. Conformational studies of khellinone and visnaginone

et al. 2012

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The structural analysis of khellinone and visnaginone indicated the planarity of the benzo [b]furan ring system. The oxygen or carbon atoms of the substituents, -OH, -OCH 3 , and -C(=O)CH 3 , are nearly coplanar with the aromatic ring. The molecular conformation is stabilized by the intramolecular O-HÁÁÁO hydrogen bond formed between the ortho-substituted hydroxyl and acetyl groups. The intermolecular contacts present in the crystal structure are the C-HÁÁÁO and C-HÁÁÁp interactions and the pÁÁÁ p stacking. The energy surface for the internal rotation about the C sp2 -O/C bonds in the khellinone and visnaginone molecules has been explored by quantum-chemical calculations. The density functional theory (DFT) methods yielded three stable conformers of khellinone and two of visnaginone obtained by a rotation of the methoxy group about the C4 sp2 -OCH 3 bond. The most stable conformation in the gas phase is consistent with the stereochemistry of the molecules adopted in the solid. The secondary minima conformers have energies higher by 0.3-1.8 kcal/mol. The energy of the intramolecular O-HÁÁÁO interactions, present in the molecular structure of all stable conformers, is around 18 kcal/mol at the DFT level. A complete and reliable assignment of the bands in the IR and Raman spectra of both compounds has been performed.

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“…Ring opening of the g-pyrone ring with KOH gave the ketones 9a and 9b according to the reported procedures. 57,58) Conversion of 9a to 4,9-dimethoxy-5-oxo-5H-furo[3,2-g]chromene-6-carbaldehyde 10 was carried out via Vilsmeier-Haack reaction. 59) Subjecting 9b to Claisen Schmidt condensation with benzaldehyde produced 1-(6-hydroxy-4-methoxy-1-benzofuran-5-yl)-3-phenylprop-2-en-1-one 11 60) which by oxidative cyclization with selenium dioxide in butanol gave the furoflavone derivative 12.…”

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confidence: 99%

Synthesis and Anticonvulsant Activity of Certain Substituted Furochromone, Benzofuran and Flavone Derivatives

Ragab

El‐Sayed

Eissa

et al. 2010

CHEMICAL & PHARMACEUTICAL BULLETIN

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Despite the optimal use of the currently available antiepileptic drugs, 30 to 40% of the epileptic population fails to experience seizure control, and others do so only at the expense of significant toxic effects that range in severity from minimal brain impairment to death from aplastic anemia or hepatic failure.1-3) These facts provoked the need for new anticonvulsant drugs with higher potency and fewer side effects. Several studies reported that chromone derivatives are promising anticonvulsant candidates that perform their activity through a g-aminobutyric acid (GABA)-mediated mechanism. [4][5][6][7][8][9][10][11][12][13][14][15][16][17] Likewise, flavones (2-phenylbenzopyrons) are with a well known positive GABA-modulating ability; their central activity was attributed to their potential to penetrate the blood-brain barrier which is strongly correlated to their lipophilicity.18) Semicarbazones and their bioisosteres thiosemicarbazones, have a documented essential role in the design of novel anticonvulsant agents that performing their anticonvulsant activity also through a GABA-mediated mechanism.19-41) Extensive structure-activity relationship studies proposed certain pharmacophoric requirements for (thio)-semicarbazones interaction at the binding site which are a hydrophobic binding area represented by aryl or heteroaryl group and a hydrogen bonding domain represented by the NH-CO(S)-NH system. [24][25][26]33,38) It was suggested that (thio)semicarbazones anticonvulsant activity is mediated through GABA-mediated mechanism. 19,22,29,32,37,41) In the present investigation the two anticonvulsant candidates, chromones or flavones and thiosemicarbazones, were amalgamated to obtain more potent anticonvulsants compounds of series 1 and 2. In the synthesized hybrid compounds the chromone or the furochromone ring acts as the hydrophobic aryl ring required for binding which itself possesses anticonvulsant tendency. On the other hand, various bicyclic heterocycles containing thiosemicarbazono group showed significant anticonvulsant activity. 33,34,[42][43][44] Herein the tricyclic furochromone moiety was simplified to the bicyclic benzofuran system, which was reported to possess anticonvulsant activity [42][43][44] to give compounds of series 3. Obviously, the compounds of this series are the bicyclic analogs of the reported phenyl congener 4 synthesized by Dimmock et al. which showed marked anticonvulsant activity. 20) Replacement of the phenyl ring in 4 by the bicyclic benzofuran structure is thought to increase the hydrophobic aryl area which binds to the binding site and thus may enhance the binding. Moreover, the effect of the hydrophobic group on the terminal amino group of the thiosemicarbazono moiety was studied in the synthesized compounds of series 1, 2 and 3.Due to certain limitations associated with the (thio)semicarbazone functionality, mainly the poor solubility and liability to metabolism 45) ; improvement of the molecule, pharmacologically and pharmaceutically, was carried out by replacement of the th...

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Die Konstitution des Kellins (aus Ammi visnaga) (I. Mitteil. über natürliche Chromone)

Cited by 76 publications

References 1 publication

Benzofuran–Morpholinomethyl–Pyrazoline Hybrids as a New Class of Vasorelaxant Agents: Synthesis and Quantitative Structure–Activity Relationship Study

Benzofuran–Morpholinomethyl–Pyrazoline Hybrids as a New Class of Vasorelaxant Agents: Synthesis and Quantitative Structure–Activity Relationship Study

Derivatives of benzo[b]furan. Part I. Conformational studies of khellinone and visnaginone

Synthesis and Anticonvulsant Activity of Certain Substituted Furochromone, Benzofuran and Flavone Derivatives

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