Carbon‐13 NMR spectral studies on chalcones and acetophenones

Patra, Amarendra; Ghosh, Goutam; Sengupta, P. K.; Nath, Swadhin

doi:10.1002/mrc.1260250815

Cited by 25 publications

(11 citation statements)

References 4 publications

(1 reference statement)

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“…Similar long-range effects to olefinic carbons were also observed for chrysin,' for example. The 'H NMR spectrum of monodeuteriated (on average) 2,2'-dihydroxy-4,4-dimethoxybenzophenone (27) shows two resonances for the OH resonance, similar to those observed for monodeuteriated 2,6-dihydroxyacetophenone.…”

Section: Correlation With Bond Ordersupporting

confidence: 64%

Substituent effects on deuterium isotope effects on nuclear shielding of intramolecularly hydrogen‐bonded aromatic ketones, aldehydes and esters

Hansen

1993

Magnetic Reson in Chemistry

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Deuterium isotope effects on 13C nuclear shielding, "AC(OD), were investigated for a large number of substituted ortho-substituted aromatic hydroxyacyl compounds of the type salicylaldehyde, 2-hydroxyacetophenone, etc. The isotope effects were analysed as a function of substitution patterns. 'AC-Z(OD) shows a linear dependence on 6OH, with one slope for 4and &substituted derivatives and another for Ssubstituted derivatives. A similar pattern is also found for the long range isotope effects. In addition, isotope effects also correlate with ''C chemical shifts. Isotope effects in o-hydroxyacetophenones can be predicted from the &OH and "AC(0D) values of salicylaldehyde, and vice versa. The isotope effects were analysed in terms of a vibrational term related to the intramolecular hydrogen bond and an electronic term related to the substituent influence on the transmission of the effect along the pathway between the deuterium-substituted oxygen and the carbon in question. 'AC(0D) isotope effects are found to depend on the one-bond bond order of the C=C bond of the unsubstituted hydrocarbons. Long-range isotope effects are observed to the olefinic carbons of 2-hydroxychalcone, whereas no effects beyond C-1' are seen in o-hydroxyketones or o-hydroxybenzophenones. The tautomeric equilibrium of usnic acid is perturbed by the removal of the weak hydrogen bond between 9-OH and the carbonyl group at C-1.KEY WORDS Secondary isotope effects on nuclear shielding Long-range isotope effects Intramolecular hydrogen bonds Resonance-assisted hydrogen bonding o-Hydroxyacyl compounds Isotopic perturbation of equilibrium

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Section: Correlation With Bond Ordersupporting

confidence: 64%

Substituent effects on deuterium isotope effects on nuclear shielding of intramolecularly hydrogen‐bonded aromatic ketones, aldehydes and esters

Hansen

1993

Magnetic Reson in Chemistry

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“…Esses dois aneis aromáticos estão unidos por um sistema carbonílico de três carbonos ,insaturados. Portanto, a estrutura molecular do HYTPHENYL é típica de uma chalcona (PATRA et al, 1987).…”

Section: Resultsunclassified

Comportamento Voltamétrico da Chalcona [2E-1-(2’-Hidroxi-3’, 4’, 6’-trimetóxifenil)-3-(fenil)-prop-2-en-1-ona] Derivada de Acetofenona Natural / Voltammetric Behavior of Chalcone [2E-1- (2'-Hydroxy-3', 4', 6'-trimethoxyphenyl)-3-(phenyl)-prop-2-en-1-one] Derived from Natural Acetophenone

Paiva¹,

Rodrigues²,

Silva³

et al. 2021

BJDV

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RESUMOAs chalconas são importantes intermediários na síntese de compostos biologicamente ativos como os flavonoides e seus derivados. Neste trabalho, foi realizado o estudo do comportamento eletroquímico de uma nova chalcona. A chalcona 2E-1-(2'-Hidróxi-3', 4', 6'-trimetóxifenil)-3-(fenil)-prop-2-en-1-ona (HYTPHENYL) foi sintetizada de uma acetofenona natural isolada da casca do caule da planta Croton anisodontus Müll. Arg. O mecanismo redox do HYTPHENYL registrado em meio praticamente aquoso envolve dois elétrons, num processo irreversível compreendido de duas transferências sucessivas de um elétron no mesmo potencial. A oxidação do HYTPHENYL envolve a formação de um radical fenoxil resultante da retirada de um elétron do grupo 2'-hidroxila seguido da abstração de um íon H + e na sequência, o radical fenoxil muito provavelmente forma um dímero.Palavras chaves: Chalcona. Estudo eletroquímico. HYTPHENYL. Produtos naturais.

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“…Arg stem bark resulted in a yield of 1.59%, which, after column chromatography, was split into various fractions, including a chloroform fraction (42% of extractive, dry weight). After repeat chromatography, this fraction yielded a compound that from melting point, IR, 1 H and 13 C spectroscopic, and mass spectrometric data was proved to be 2-hydroxy-3,4,6-trimethoxy-acetophenone [1,9]. This is the first time that this compound has been reported for this species.…”

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confidence: 80%

Identification and Modulatory Activity Assessment of 2-Hydroxy-3,4,6-trimethoxyacetophenone Isolated fromCroton anisodontusMull. Arg.(Euphorbiaceae)

Oliveira

Teixeira

Coutinho

et al. 2014

Natural Product Communications

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The n-hexane extract of the stem bark of Croton anisodontus yielded 2-hydroxy-3,4,6-trimethoxyacetophenone, a well-known substance, but isolated from this species for the first time. The antimicrobial and modulatory activities of the compound towards Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Candida albicans, C. krusei and C. tropicalis strains were assessed. Antibiotics such as amikacin, gentamicin and neomycin were used in a subinhibitory concentration. Significant activity was observed towards P. aeruginosa and S. aureus 358, with p < 0.001 in association with amikacin. The present results place C. anisodontus as an alternative source of 2-hydroxy-3,4,6-trimethoxyacetophenone with antibacterial potential.

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Carbon‐13 NMR spectral studies on chalcones and acetophenones

Abstract: Carbon-I3 signal assignments of eighteen polyoxygenated chalcones and thirteen polysubstituted acetophenones are reported.

Cited by 25 publications

References 4 publications

Substituent effects on deuterium isotope effects on nuclear shielding of intramolecularly hydrogen‐bonded aromatic ketones, aldehydes and esters

Substituent effects on deuterium isotope effects on nuclear shielding of intramolecularly hydrogen‐bonded aromatic ketones, aldehydes and esters

Comportamento Voltamétrico da Chalcona [2E-1-(2’-Hidroxi-3’, 4’, 6’-trimetóxifenil)-3-(fenil)-prop-2-en-1-ona] Derivada de Acetofenona Natural / Voltammetric Behavior of Chalcone [2E-1- (2'-Hydroxy-3', 4', 6'-trimethoxyphenyl)-3-(phenyl)-prop-2-en-1-one] Derived from Natural Acetophenone

Identification and Modulatory Activity Assessment of 2-Hydroxy-3,4,6-trimethoxyacetophenone Isolated fromCroton anisodontusMull. Arg.(Euphorbiaceae)

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