Phenol protein coagulation

Non-sulfonated lignins find utility as emulsifiers and stabilizers in water-based asphalt emulsions, as coreactants in phenolic binder applications, as negative plate expanders in lead acid storage batteries, as protein coagulants in fat rendering, and as flocculants in waste water systems. 

The network structure of lignin, which is made of phenol units, coagulates the cell wall in wood tissue, which is composed of cellulose and hemicellulose. Lignin is currently a waste product because of its complicated structure [1-4], It is produced by an oxidative polymerization of coniferyl alcohol, sinapil alcohol, and cumarol alcohol (Figure 1) catalyzed by metalloenzymes such as laccase and peroxidases. Laccase is a protein whose active center contains four coppers per one subunit [5-20],... 

Eugenol, like other phenolic compounds, is a structurally non-specific drug. The pharmacological action is not directly subordinated to chemical structure, except to the extent that structure affects physicochemical properties, as adsorption, solubility, pKa, and oxidation-reduction potential, factors which influence permeability, depolarization of the membrane and protein coagulation [34],... 

Resorcinol is a phenol derivative and its proteolytic power is about 1/40 of that of phenol. It breaks the weak hydrogen links of keratin and acts as a proteolytic agent, even at concentrations as low as 5%. At higher concentrations, it can also precipitate skin proteins and become a protein coagulant. 

The crotonic acid (Figure 25.14) that it contains is an irritant that accelerates epidermal lysis and enhances the cutaneous penetration of the phenol. Some authors maintain that a phenol peel will only produce good results if croton oil is present. The croton oil enhances dermal penetration and epidermal protein coagulation, and thus lower concentrations of phenol can be used. We have seen, however, that many phenol peel formulations do not contain croton oil. 

A phenol peel is not used to treat telangiectasias, even though the more superficial ones usually disappear through protein coagulation along with the superficial layers of the skin. Deeper telangiectasias can become even more deeply embedded in the dermis as the new layer of dermal collagen and elastin form. Therefore, a phenol peel... 

The must is subsequently sterilized, boiling being the most commonly used method (McConnell and Schramm, 1995 Navratil et al., 2001 Ukpabi, 2006). Heat treatments also have the potential to alter the antioxidant capacity by changing their phenolic profiles (Wintersteen et al., 2005). However, other techniques are described in the literature. These include the use of metabisulfite (sodium or potassium salts or in commercial form as Campden tablets)—releases sulfur dioxide that either kills or inactivates most microbes (McConnell and Schramm, 1995 Roldan et al., 2011), sulfur dioxide gas (Pereira et al., 2009 Ukpabi, 2006), pasteurization (McConnell and Schramm, 1995 Mendes-Ferreira et al., 2010), and ultrafiltration, with a 50-kDa molecular weight cutoff (McConnell and Schramm, 1995). Some of these methods also promote the removal of proteins by denaturation and coagulation, resulting in more rapid clarification during maturation. 

An occlusive dressing applied quickly after phenol helps it macerate and deepens its action. An occlusive dressing applied immediately after TCA creates a barrier to epidermal water evaporation and to the water in the solution itself. Under occlusion, this water accumulates in the uppermost layers of the skin, where it dilutes the TCA fairly rapidly. With phenol, this slight dilution enhances its penetration. An occlusive dressing applied 30 minutes after TCA does not dilute the acid, as it has had enough time to coagulate the proteins in the skin and neutralize itself by combining with the proteins before occlusion can dilute it. 

Phenol coagulates proteins simply by combining with them, and this produces frosting similar to that occurring when the normally transparent proteins of an egg white become cloudy on cooking, as a result of their three-... 

By separating the phenol from the protein that it has coagulated, alcohol can enhance the action of the acid on another protein. 

Dried albumen, yellow, transparent, amorphous lumps or scales, or yellow powder. Decomposes in moist air, In water it swells at first, then dissolves gradually, The soln coagulates at 61° (because of denaturation of the proteins). Albumen solos are also denatured on contact with the following chemicals Salts of copper iron, mercury and silver H>0>, phenol- picric acid, alum, tannic acid, formaldehyde-ether, alcohol. 

I. Mechanism of toxicity. Phenol denatures protein, dismpts the cell wall, and produces coagulative necrosis. It may cause corrosive injury to the eyes, skin, and respiratory tract. Systemic absorption causes CNS stimulation. The mechanism of CNS intoxication is not known. Some phenolic compounds (eg, dinitrophenol and hydroquinone) may induce hemolysis and methemoglobinemia (see p 261). 

To eliminate contaminating bacteria, the yeast slurry can be acid washed. Also, sometimes (but less frequently these days), the yeast slurry is sieved to remove contaminating trub (i.e. coagulated protein-phenol solid material). 

Agents that coagulate or denature proteins (e.g., mercuric salts, phenols) produce local irritation or necrosis. 

Phenol peels are categorized as deep peels. Similar to TCA, phenol works through protein denaturation and coagulation. However, phenol differs from TCA in that it penetrates quickly to the level of the reticular dermis. Phenol is partially detoxified by the liver and excreted through the kidneys. Percutaneous absorption of phenol can lead to rapid elevation of serum phenol levels, resulting in systemic toxicity and cardiac arrhythmias. Therefore, all patients should be cleared from a cardiac, hepatic, and renal standpoint preoperatively. In addition, intraoperative cardiac monitoring is imperative. 

For the most part, phenol peels fall into the category of deep peels. In a fashion similar to TCA, phenol exerts its actions by protein denaturation and coagulation however it quickly penetrates the skin to the level of the reticular dermis. Thus, phenol peels are typically quick peels with little time for adjusting the peel depth. There are a number of phenol peel solutions used historically with the Baker-Gordan formulatian being the most recognized. Most solutions have phenol, water, croton oil, and either Septisol (Steiis Corp., Mentor, OH), or other oils such as sesame seed or olive oil. 

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