Biphasic polyphenols

Enzymes as different as yeast alcohol oxidase, mushroom polyphenol oxidase, and horse-liver alcohol dehydrogenase demonstrated vastly increased enzymatic activity in several different solvents upon an increase in the water content, which always remained below the solubility limit (Zaks, 1988b). While much less water was required for maximal activity in hydrophobic than in hydrophilic solvents, relative saturation seems to be most relevant to determining the level of catalytic activity. Correspondingly, miscibility of a solvent with water is not a decisive criterion upon transition from a monophasic to a biphasic solvent system, no significant change in activity level was observed (Narayan, 1993). Therefore, the level of water essential for activity depends more on the solvent than on the enzyme. 

The enzymatic synthesis of polyphenols was carried out not only in the monophasic solvents but in interfacial systems such as micelles, reverse micelles, and biphasic and Langmuir trough systems, p-Phenylphenol was polymerized in an aqueous surfactant solution to give the polymer with a narrower molecular weight distribution in comparison with that obtained in the aqueous 1,4-dioxane.20... 

Kaplan et al. [92] has demonstrated that HRP-mediated polymerization of polyphenols can be carried out in solution, emulsions or biphasic mixtures of buffer solution and isooctane. In the case of biphasic mixtures, polymers with molecular weights around 2 kDa were achieved with polydispersities about 2.0. These polymerizations were undertaken in an isooctane/buffer biphasic medium. The authors showed that higher molecular weight polymer and greater control over the poly-dispersity could be achieved if the reaction was carried out in a reverse micelle stabilized by a surfactant in water. 

Table 3 gives the third-order nonlinear optical properties of bioengineered polymers prepared by enzyme-catalyzed polymerization using horseradish peroxidase in biphasic solvent systems. Water-immiscible solvents used for the biphasic media are benzene, chloroform, toluene, tetrahydrofuran, and isooctane. Third-order nonlinear optical properties of homopolymers and copolymers prepared in biphasic solvent systems are similar to those of polymers prepared in monophasic systems. The values of polyaromatic amines solutions measured at 532 nm are one to two orders higher than the x values observed with polyphenolic compounds. Third-order nonlinear optical properties of copolymers of aromatic amines with... 

Four interfacial systems, micelles, reverse micelles, a biphasic, and Langmuir trough systems, have been examined for preparation of the enzymatic S5m-thesis of polyphenols. In the polymerization in micelle solution consisting of surfactant and buffer, the obtained polymer fromp-phenylphenol had narrow molecular weight distribution in comparison of that in the aqueous 1,4-dioxane (239). 

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