17423-63-1

Upstream product

• 90-05-1 2-methoxy-phenol 
• 92160-61-7 4,4'-diiodo-3,3'-dimethoxylbiphenyl 
• 179902-22-8 1-acetoxy-4-iodo-2-methoxy-benzene 
• 52041-17-5 4,4'-Diacetoxy-3,3'-dimethoxy-biphenyl 
• 4433-09-4 4,4'-Dihydroxy-3,3'-dimethoxybiphenyl 

Relevant academic research and scientific papers

Two oxidation sites for low redox potential substrates: A directed mutagenesis, kinetic, and crystallographic study on pleurotus eryngii versatile peroxidase

Versatile peroxidase shares with manganese peroxidase and lignin peroxidase the ability to oxidize Mn2+ and high redox potential aromatic compounds, respectively. Moreover, it is also able to oxidize phenols (and low redox potential dyes) at two catalytic sites, as shown by biphasic kinetics. A high efficiency site (with 2,6-dimethoxyphenol and p-hydroquinone catalytic efficiencies of ～70 and ～700 s-1 mM-1, respectively) was localized at the same exposed Trp-164 responsible for high redox potential substrate oxidation (as shown by activity loss in the W164S variant). The second site, characterized by low catalytic efficiency (～3 and ～50 s-1 mM-1 for 2,6-dimethoxyphenol and p-hydroquinone, respectively) was localized at the main heme access channel. Steady-state and transient-state kinetics for oxidation of phenols and dyes at the latter site were improved when side chains of residues forming the heme channel edge were removed in single and multiple variants. Among them, the E140G/K176G, E140G/P141G/K176G, and E140G/W164S/K176G variants attained catalytic efficiencies for oxidation of 2,2′-azino-bis(3- ethylbenzothiazoline-6-sulfonate) at the heme channel similar to those of the exposed tryptophan site. The heme channel enlargement shown by x-ray diffraction of the E140G, P141G, K176G, and E140G/K176G variants would allow a better substrate accommodation near the heme, as revealed by the up to 26-fold lower Km values (compared with native VP). The resulting interactions were shown by the x-ray structure of the E140G-guaiacol complex, which includes two H-bonds of the substrate with Arg-43 and Pro-139 in the distal heme pocket (at the end of the heme channel) and several hydrophobic interactions with other residues and the heme cofactor.

Hydrophilic ionic liquids as reaction media for the determination of guaiacol using horseradish and soybean peroxidases

The advantages of hydrophilic ionic liquids - 1-butyl-2-methylimidazolium and N-butyl-3-methylpyridinium tetrafluoroborates - over conventional polar solvents (DMSO and acetonitrile) for the enzymatic determination of 0.05-3 mm guaiacol in the reaction media containing 20-40 vol% H2O are shown as the result of a comparative study of the kinetics of guaiacol oxidation by ButOOH catalyzed by native horseradish and soybean peroxidases.

An iron(iii) tetradentate monoamido complex as a nonheme iron-based peroxidase mimetic

A mononuclear iron(iii) complex of a noncyclic tetradentate monoamido ligand, Fe(iii)mpaq, catalyses the oxidation of Orange II, guaiacol, ABTS and Amplex Red with H2O2 in aqueous solutions at neutral pH. Under identical conditions, other structurally related nonheme iron complexes showed only negligible activities.

Kinetics of Oxidative Coupling of Phenols. Oxidation of Guaiacol by Alkaline Hexacyanoferrate(III)

The reaction between guaiacol and alkaline hexacyanoferrate(III), at constant ionic strength, gave a coupled product, 3:3'-dimethoxydiphenoquinone.The rate of the reaction was dependent on the first orders of the concentrations of substrate, oxidant, and alkali.The rate determining step involved the formation of a radical intermediate, which was detected by ESR spectroscopy.

Cytochrome: C -poly(acrylic acid) conjugates with improved peroxidase turnover number

Cytochrome c-poly(acrylic acid) (cyt c-PAA) conjugates with 34-fold enchancement in peroxidase turnover number (kcat) are reported. Cyt c-PAA conjugates were prepared by carbodiimide coupling. PAA with molecular weight (Mw) ranging from 1.8k to 250k g mol-1 were employed, and the effect of PAA Mw on peroxiodase kinetics was assessed. The kcat value increased with increased Mw of PAA, ranging from 0.077(±0.002) s-1 in the absence of PAA to 2.66(±0.08) s-1 for the conjugate of cyt c with 250k PAA. Enzymatic activity studies over pH 6-8 indicated improved activity for cyt c-PAA conjugates at neutral or slightly alkaline pH. Examination of the cyt c heme spectroscopy in the presence of H2O2 revealed that formation of compound III, a reactive intermediate that leads to enzyme inactivation, was supressed in cyt c-PAA conjugates. Thus, we suggest the kcat enhancement can be attributed to acidification of the pH microenvironment and inhibition of the formation of a reactive intermediate that deactivates cyt c during the catalytic cycle.

Use of apomyoglobin to gently remove heme from a H2O2-dependent cytochrome P450 and allow its reconstitution

The heme of hydrogen peroxide-dependent cytochrome P450BSβ (P450BSβ) was removed by apomyoglobin under mild conditions to give apo-P450BSβ without the need for acidic conditions and organic solvents. The circular dichroism spectrum of the apo-P450BSβ was essentially identical to that of holo-P450BSβ, showing a small structural change resulting from the removal of heme using apomyoglobin. The apo-P450BSβ was reconstituted with hemin or manganese protoporphyrin IX (MnPPIX), and the resulting reconstituted P450BSβ catalyzed the one-electron oxidation of guaiacol using hydrogen peroxide as an oxidant. A higher catalytic activity was observed for P450BSβ reconstituted with MnPPIX when meta-chloroperoxybenzoic acid (mCPBA) was used as the oxidant.

Synthesis of copper ion incorporated horseradish peroxidase-based hybrid nanoflowers for enhanced catalytic activity and stability

In this study, we report the preparation, catalytic activity and stability of a hybrid nanoflower (hNF) formed from horseradish peroxidase (HRP) enzyme and copper ions (Cu2+). We studied the morphology of hNFs as a function of the concentrations of copper (Cu2+) ions, chloride ions (Cl-) and HRP enzyme, the pH of the buffer solution (phosphate buffered saline), and the temperature of the reaction. The effects of morphology on the catalytic activity and stability of hNFs were evaluated by oxidation of guaiacol (2-methoxyphenol) to colored 3,3-dimethoxy-4,4-diphenoquinone in the presence of hydrogen peroxide (H2O2). The enhanced activity of hNFs synthesized (from 0.02 mg mL-1 HRP in 10 mM PBS (pH 7.4) at +4°C) was 17595 U mg-1, which was ～300% higher than free HRP in PBS, where it achieved an activity of 5952 U mg-1. In terms of stability, these hNFs stored in PBS buffer at +4°C and room temperature (RT = 20°C) lost 4% and 20%, respectively, of their initial catalytic activities within 30 days. Finally, we demonstrated that these hNFs can be utilized as sensors for the detection of dopamine.

Unusually high thermal stability and peroxidase activity of cytochrome c in ionic liquid colloidal formulation

Ionic liquid (IL) surfactant choline dioctylsulfosuccinate, [Cho][AOT], formed polydispersed vesicular structures in the IL, ethylmethylimidazolium ethylsulfate, [C2mim][C2OSO3]. Cytochrome c dissolved in such a colloidal medium has shown very high peroxidase activity (～2 times to that in neat IL and ～4 times to that in an aqueous buffer). Significantly, the enzyme retained both structural stability and functional activity in IL colloidal solutions up to 180°C, demonstrating the suitability of the system as a high temperature bio-catalytic reactor.

Guaiacol oxidation products in the enzyme-activity assay reaction by horseradish peroxidase catalysis

In the horseradish peroxidase (HRP)-catalyzed oxidation of guaiacol (1), trimeric products, and diastereomers of biphenoquinones have been newly identified. The oxidation product was analyzed by HPLC, liquid chromatography electrospray ionization mass spe