88875-74-5Relevant academic research and scientific papers
Bio-inspired flavonol and quinolone dioxygenation by a non-heme iron catalyst modeling the action of flavonol and 3-hydroxy-4(1H)-quinolone 2,4-dioxygenases
Pap, József S.,Matuz, Andrea,Baráth, Gábor,Kripli, Balázs,Giorgi, Michel,Speier, Gábor,Kaizer, József
, p. 15 - 21 (2012)
The mononuclear complex, FeIII(O-bs)(salen) (salenH2 = 1,6-bis(2-hydroxyphenyl)-2,5-diaza-hexa-1,5-diene; O-bsH = O-benzoylsalicylic acid) was synthesized as synthetic enzyme-depside complex, and characterized by spectroscopic methods and X-ray crystal analysis. The dioxygenation of flavonol (flaH) and 3-hydroxy-4-quinolone (quinH2) derivatives in the presence of catalytic amounts of FeIII(O-bs)(salen) results in the oxidative cleavage of the heterocyclic ring to give the corresponding O-benzoylsalicylic and anthranilic acid derivatives with concomitant release of carbon monoxide. These reactions can be regarded as biomimetic functional models with relevance to the iron-containing flavonol and the cofactor-independent 3-hydroxy-4(1H)-quinolone 2,4-dioxygenases.
Benzoylsalicylic acid derivatives as defense activators in tobacco and Arabidopsis
Kamatham, Samuel,Pallu, Reddanna,Pasupulati, Anil Kumar,Singh, Surya Satyanarayana,Gudipalli, Padmaja
, p. 160 - 169 (2017/08/29)
Systemic acquired resistance (SAR) is a long lasting inducible whole plant immunity often induced by either pathogens or chemical elicitors. Salicylic acid (SA) is a known SAR signal against a broad spectrum of pathogens in plants. In a recent study, we have reported that benzoylsalicylic acid (BzSA) is a SAR inducer in tobacco and Arabidopsis plants. Here, we have synthesized BzSA derivatives using SA and benzoyl chlorides of various moieties as substrates. The chemical structures of BzSA derivatives were elucidated using Infrared spectroscopy (IR), Nuclear magnetic spectroscopy (NMR) and High-resolution mass spectrometer (HRMS) analysis. The bioefficacy of BzSA derivatives in inducing defense response against tobacco mosaic virus (TMV) was investigated in tobacco and SA abolished transgenic NahG Arabidopsis plants. Interestingly, pre-treatment of local leaves of tobacco with BzSA derivatives enhanced the expression of SAR genes such as NPR1 [Non-expressor of pathogenesis-related (PR) genes 1], PR and other defense marker genes (HSR203, SIPK, WIPK) in systemic leaves. Pre-treatment of BzSA derivatives reduced the spread of TMV infection to uninfected areas by restricting lesion number and diameter both in local and systemic leaves of tobacco in a dose-dependent manner. Furthermore, pre-treatment of BzSA derivatives in local leaves of SA deficient Arabidopsis NahG plants induced SAR through AtPR1 and AtPR5 gene expression and reduced leaf necrosis and curling symptoms in systemic leaves as compared to BzSA. These results suggest that BzSA derivatives are potent SAR inducers against TMV in tobacco and Arabidopsis.
A Novel Synthesis of 4H-Chromen-4-ones via Intramolecular Wittig Reaction
Kumar, Pradeep,Bodas, Mandar S.
, p. 3821 - 3823 (2007/10/03)
formula presented The acylphosphoranes formed in a sequential manner from the reaction of the silyl ester of O-acyl(aroyl)salicylic acids and (trimethylsilyl)-methylenetriphenylphosphorane undergo intramolecular Wittig cyclization on the ester carbonyl to afford the 4H-chromen-4-ones in good to excellent yields.
Kinetics and mechanism of the oxygenation of potassium flavonolate. Evidence for an electron transfer mechanism
Barhacs, Laszlo,Kaizer, Jozsef,Speier, Gabor
, p. 3449 - 3452 (2007/10/03)
The oxygenation of the potassium salt of flavonol (flaH) in absolute DMF leads to potassium O-benzoylsalicylate and carbon monoxide in 95% yield at 40 °C. Kinetic measurements resulted in the rate law -d[flaK]/dt = k2[flaK][O2]. The rate constant, activation enthalpy, and entropy at 313.16 K are as follows: k2/M-1 s-1 = (3.28 ± 0.10) × 10-1 ΔH?/kJ mol-1 = 29 ± 2, ΔS?/J mol-1 K-1 = -161 ± 6. The reaction fits a Hammett linear free energy relationship for 4′-substituted flavonols, and electron-releasing groups make the oxygenation reaction faster. The anodic oxidation wave potentials Ea of the 4′-substituted flavonolates correlate well with reaction rates. At more negative Ea values faster reaction rates were observed. EPR spectrum of the reaction mixture (g = 2.0038, dH = 1.8 G, aH = 0.9 G) showed the presence of flavonoxyl radical as a result of a SET from the flavonolate to dioxygen.
