scholarly journals The biosynthesis of patulin: The mechanism of oxidative aromatic ring cleavage and loss of side chain protons from aromatic intermediates.

1983 ◽  
Vol 31 (1) ◽  
pp. 362-365 ◽  
Author(s):  
Hiroshi Iijima ◽  
Hiroshi Noguchi ◽  
Yutaka Ebizuka ◽  
Ushio Sankawa ◽  
Haruo Seto
Keyword(s):  
Aromatic Ring ◽  
Ring Cleavage ◽  
Side Chain ◽  
Aromatic Ring Cleavage

scholarly journals Ozonolysis of surface-adsorbed methoxyphenols: kinetics of aromatic ring cleavage vs. alkene side-chain oxidation

2014 ◽  
Vol 14 (1) ◽  
pp. 47-60 ◽  
Author(s):  
E. M. O'Neill ◽  
A. Z. Kawam ◽  
D. A. Van Ry ◽  
R. Z. Hinrichs
Keyword(s):  
Aromatic Ring ◽  
Ring Cleavage ◽  
Biomass Combustion ◽  
Side Chain ◽  
Visible Radiation ◽  
Diffuse Reflectance Infrared Spectroscopy ◽  
Order Of Magnitude ◽  
Aromatic Ring Cleavage ◽  
Α Al2o3 ◽  
Diffuse Reflectance Infrared

Abstract. Lignin pyrolysis products, which include a variety of substituted methoxyphenols, constitute a major component of organics released by biomass combustion, and may play a central role in the formation of atmospheric brown carbon. Understanding the atmospheric fate of these compounds upon exposure to trace gases is therefore critical to predicting the chemical and physical properties of biomass burning aerosol. We used diffuse reflectance infrared spectroscopy to monitor the heterogeneous ozonolysis of 4-propylguaiacol, eugenol, and isoeugenol adsorbed on NaCl and α-Al2O3 substrates. Adsorption of gaseous methoxyphenols onto these substrates produced near-monolayer surface concentrations of 3 × 1018 molecules m−2. The subsequent dark heterogeneous ozonolysis of adsorbed 4-propylguaiacol cleaved the aromatic ring between the methoxy and phenol groups with the product conclusively identified by GC-MS and 1H-NMR. Kinetic analysis of eugenol and isoeugenol dark ozonolysis also suggested the formation of ring-cleaved products, although ozonolysis of the unsaturated substituent groups forming carboxylic acids and aldehydes was an order of magnitude faster. Average uptake coefficients for NaCl-adsorbed methoxyphenols were γ = 2.3 (± 0.8) × 10−7 and 2 (± 1) × 10−6 for ozonolysis of the aromatic ring and the unsaturated side chain, respectively, and reactions on α-Al2O3 were approximately two times slower. UV–visible radiation (λ > 300 nm) enhanced eugenol ozonolysis of the aromatic ring by a factor of 4(± 1) but had no effect on ozonolysis of the alkene side chain.

scholarly journals Ozonolysis of surface adsorbed methoxyphenols: kinetics of aromatic ring cleavage vs. alkene side-chain oxidation

2013 ◽  
Vol 13 (7) ◽  
pp. 19971-20009
Author(s):  
E. M. O'Neill ◽  
A. Z. Kawam ◽  
D. A. Van Ry ◽  
R. Z. Hinrichs
Keyword(s):  
Aromatic Ring ◽  
Ring Cleavage ◽  
Biomass Combustion ◽  
Side Chain ◽  
Visible Radiation ◽  
Diffuse Reflectance Infrared Spectroscopy ◽  
Order Of Magnitude ◽  
Aromatic Ring Cleavage ◽  
Α Al2o3 ◽  
Diffuse Reflectance Infrared

Abstract. Lignin pyrolysis products, which include a variety of substituted methoxyphenols, constitute a major component of organics released by biomass combustion and may play a central role in the formation of atmospheric brown carbon. Understanding the atmospheric fate of these compounds upon exposure to trace gases is therefore critical to predicting the chemical and physical properties of biomass burning aerosol. We used diffuse reflectance infrared spectroscopy to monitor the heterogeneous ozonolysis of 4-propylguaiacol, eugenol, and isoeugenol adsorbed on NaCl and α-Al2O3 substrates. Adsorption of gaseous methoxyphenols onto these substrates produced near monolayer surface concentrations of 3 × 1018 molecules m-2. The subsequent dark heterogeneous ozonolysis of adsorbed 4-propylguaiacol cleaved the aromatic ring between the methoxy and phenol groups with the product conclusively identified by GC-MS and 1H-NMR. Kinetic analysis of eugenol and isoeugenol dark ozonolysis also suggested the formation of ring-cleaved products, although ozonolysis of the unsaturated substituent groups forming carboxylic acids and aldehydes was an order of magnitude faster. Average uptake coefficients for NaCl-adsorbed methoxyphenols were γ = 2.3 (±0.8) × 10-7 and 2 (±1) × 10-6 for ozonolysis of the aromatic ring and the unsaturated side chain, respectively, and reactions on α-Al2O3 were approximately two times slower. UV-visible radiation (λ>300 nm) enhanced eugenol ozonolysis of the aromatic ring by a factor of 4(±1) but had no effect on ozonolysis of the alkene side-chain.

Mechanism of aromatic ring cleavage of a .beta.-biphenylyl ether dimer catalyzed by lignin peroxidase of Phanerochaete chrysosporium

Biochemistry ◽  
1988 ◽  
Vol 27 (13) ◽  
pp. 4787-4794 ◽  
Author(s):  
Keiji Miki ◽  
Ryuichiro Kondo ◽  
V. Renganathan ◽  
Mary B. Mayfield ◽  
Michael H. Gold
Keyword(s):  
Aromatic Ring ◽  
Phanerochaete Chrysosporium ◽  
Lignin Peroxidase ◽  
Ring Cleavage ◽  
Aromatic Ring Cleavage

scholarly journals Aromatic ring cleavage of a β-biphenyl ether dimer catalyzed by lignin peroxidase of phanerochaete chrysosporium

FEBS Letters ◽  
1987 ◽  
Vol 210 (2) ◽  
pp. 199-203 ◽  
Author(s):  
Keiji Miki ◽  
V. Renganathan ◽  
Mary B. Mayfield ◽  
Michael H. Gold
Keyword(s):  
Aromatic Ring ◽  
Phanerochaete Chrysosporium ◽  
Lignin Peroxidase ◽  
Ring Cleavage ◽  
Aromatic Ring Cleavage

Oxidation and aromatic ring cleavage of 4-methoxy and 3,4-dimethoxycennamic acid by Lentinus edodes

1994 ◽  
Vol 16 (9) ◽  
pp. 995-1000 ◽  
Author(s):  
Claudia Crestini ◽  
Giovanni Giovannozzi Sermanni
Keyword(s):  
Aromatic Ring ◽  
Ring Cleavage ◽  
Lentinus Edodes ◽  
Aromatic Ring Cleavage
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