Unusual Polycyclic Fused Product by Oxidative Enzymatic Dimerisation of 5-methylpyrogallol Catalysed by Horseradish Peroxidase/H2O2

Bouges, Hélène; Calabro, Kevin; Thomas, Olivier P.; Antoniotti, Sylvain

doi:10.3390/molecules23102619

Cited by 7 publications

(10 citation statements)

References 19 publications

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“…When 5, prepared independently, was submitted to the same reaction conditions, the dimer 6 was formed similarly (Scheme 1). A mechanistic rationale to account for this unusual product formation has been described in a separate publication [35]. It was thus established that 5 could be converted into a water-soluble dimeric product 6 in an unprecedented and surprising way.…”

Section: Resultsmentioning

confidence: 97%

“…Our initial attempts to perform the direct formylation by the action of POCl 3 and DMF following the standard procedure led to a regioisomer of 2 by formylation in ortho position relative to the methyl group. However, upon protection of the hydroxyl functions by methoxymethyl groups, ortho-lithiation could be performed efficiently, and the target atranol 2 was obtained in 85% isolated yield (39% in four steps from 4) [35]. Alternate synthesis should be performed upon methylation/formylation/demethylation by BBr 3 [36].…”

Section: Resultsmentioning

confidence: 99%

“…Scheme 1. Optimized conditions for the formation of the dimer 6 and its acetylated derivative 7 [35].…”

Section: Resultsmentioning

confidence: 99%

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Enzyme-Catalysed Conversion of Atranol and Derivatives into Dimeric Hydrosoluble Materials: Application to the Preparation of a Low-Atranol Oakmoss Absolute

2018

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Oakmoss absolute, a solvent extract from Evernia prunastri, is a valuable fragrance ingredient widely used in fine fragrance for almost two centuries. Some minor components of oakmoss absolute, such as atranol and chloroatranol, are attested contact allergens and their presence in fragrance and cosmetic products should be as low as possible. In this context, we have developed an enzyme-based protocol upon which these undesirable molecules are converted in a hydrosoluble dimeric material, and thus easily separated from the absolute by liquid–liquid extraction. Analytical and sensory analyses were performed to confirm the specificity of the process, the absence of alteration of the olfactory quality of the absolute, and the final titles of atranol and chloroatranol, which eventually were observed in the ppm range. This highly sustainable process is a viable alternative to conventional time-, energy-, and manpower-consuming techniques to produce very low-atranol oakmoss absolute.

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Section: Resultsmentioning

confidence: 97%

Section: Resultsmentioning

confidence: 99%

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Enzyme-Catalysed Conversion of Atranol and Derivatives into Dimeric Hydrosoluble Materials: Application to the Preparation of a Low-Atranol Oakmoss Absolute

2018

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“…The NMR and mass spectrometry (MS) data of the synthesized compounds already reported were in agreement with the literature values (Schemes S1–S4). − Compound 1a has a simple methyl group substituent (see Figure for the labeling figure) and was oxidized with 1 equiv of copper chloride in 30% dioxane in water. After removing the copper chloride using an HP20SS column and subjecting the crude products to high-performance liquid chromatography (HPLC) analysis, the three main products were isolated and determined to be 4a , 5a , and 6a by instrumental analysis (see Scheme ).…”

Section: Resultsmentioning

confidence: 99%

Understanding the Regioselectivity in the Oxidative Condensation of Catechins Using Pyrogallol-type Model Compounds

2020

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Catechins are found in many foods, including tea. These compounds are bioactive. Previous studies have shown that catechins form dimers on oxidation, and there seem to be distinct regioselective effects. However, the dimerization mechanism and regioselectivity are not well understood. Therefore, we investigated the oxidation of four pyrogallol-type model compounds of epigallocatechin (EGC) having various substituents with 1 equiv of copper chloride and 30% dioxane in water. Compounds having 2C−2C or 2C−4C bonds in the B-ring were obtained in different product ratios. Comparison of the oxidation rates of each compound revealed that the model compounds having an oxygen atom corresponding to the 1-position of the C-ring of EGC underwent slow oxidation. In addition, using density functional theory calculations, we found that the highest occupied molecular orbital energies of these compounds were higher than those of the others. Further, the 2C−2C-bonded oxidation product having an A-ring and an oxygen atom at the C-ring 1-position was confirmed to have the highest thermodynamic stability. From these results, it is suggested that the regioselective condensation reaction of the catechin B-ring is related to interactions between the A-rings, as indicated by earlier studies, and the presence of oxygen at the 1-position of the C-ring in EGC.

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“…Therefore, it is important to identify possible substitutes [3,4]. Haemoglobin (Hb) is a respiratory protein found in the erythrocytes of vertebrates [5][6][7], which plays important roles in oxygen transport and energy metabolism, such as oxygen transmission, the decomposition of H 2 O 2 and the transfer of electrons [8]. Wang et al [9] experimentally studied the catalytic properties of Hb peroxidase.…”

Section: Introductionmentioning

confidence: 99%

Modelling and analysis of haemoglobin catalytic reaction kinetic system

Liu

Wang

et al. 2020

Mathematical and Computer Modelling of Dynamical Systems

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In order to study whether haemoglobin (Hb) can replace peroxidase and has good catalytic properties. The key to exploring the characteristics of Hb peroxidase is to establish a suitable kinetic model, which is studied in this paper. First, according to the Hb catalytic reaction, a nonlinear system is established and improved. It is proved that the established system is in line with the practical significance. The stability of the original system is judged by analysing the stability of the simplified system. Then, considering the effect of time delay on Hb catalytic reaction, a nonlinear timedelay catalytic reaction system is obtained. For convenient application, the system is linearized using Taylor's formula, and the dynamic characteristics of Hopf bifurcation are analysed. The response diagrams of three system are plotted by setting perturbation parameters, and their variations are observed to analyse the differences among them. The results show that the nonlinear timedelay system can better describe the characteristics of the catalytic reaction.

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Unusual Polycyclic Fused Product by Oxidative Enzymatic Dimerisation of 5-methylpyrogallol Catalysed by Horseradish Peroxidase/H2O2

Cited by 7 publications

References 19 publications

Enzyme-Catalysed Conversion of Atranol and Derivatives into Dimeric Hydrosoluble Materials: Application to the Preparation of a Low-Atranol Oakmoss Absolute

Enzyme-Catalysed Conversion of Atranol and Derivatives into Dimeric Hydrosoluble Materials: Application to the Preparation of a Low-Atranol Oakmoss Absolute

Understanding the Regioselectivity in the Oxidative Condensation of Catechins Using Pyrogallol-type Model Compounds

Modelling and analysis of haemoglobin catalytic reaction kinetic system

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