Phenols biological activities

Triterpenoid Saponins Phenolic Compounds Recent Methods of Structure Determination of Prenylated Phenols Biological Activities of Phenolic Constituents of Glycyrrhiza Species... 

Wastewater. Phenol is a toxic poUutant to the waterways and has an acute toxicity (- 5 m g/L) to fish. Chlorination of water gives chlorophenols, which impart objectionable odor and taste at 0.01 mg/L. Biochemical degradation is most frequently used to treat wastewater containing phenol. Primary activated sludge, along with secondary biological treatment, reduces phenol content to below 0.1 mg/L (69). 

Biologically active terpenoids, phenols, 0-macroheterocycles, N-heterocycles, y- and 8-lactones of Japanese inedible mushrooms 98H(47)1067. 

The duration of action of acetaminophen is limited by the formation of water-soluble derivatives of the phenol (glucuronide and sulfate) that are then excreted via the kidney. Protection i)f the phenol as an ether inhibits such inactivation without diminishing biologic activity. Acetylation of p-ethoxyaniline iffords the widely used peripheral analgesic, phenacetin (25). ... 

Kozubek, A., Tyman, J. Resorcinolic lipids, the natural non-isoprenoid phenolic amphiphiles and their biological activity. Chemical Reviews, Vol.99, No.l. Qanuary 1999), pp. 1-31, ISSN 0009-2665... 

A huge variety of biologically active phenolic compounds containing one or more aromatic rings are found naturally in plant foods, where they provide much of the flavour, colour and texture. The simpler phenolic substances include ... 

Tocopherol can be produced as the pure 2R,4 R,8 R stereoisomer from natural vegetable oils. This is the most biologically active of the stereoisomers. The correct side-chain stereochemistry can be obtained using a process that involves two successive enantioselective hydrogenations.28 The optimum catalyst contains a 6, 6 -dimethoxybiphenyl phosphine ligand. This reaction has not yet been applied to the enantioselective synthesis of a-tocopherol because the cyclization step with the phenol is not enantiospecific. 

Vfe noticed that stepwise purification of the crude extracts resulted in gradually diminishing activity. When several of the identified phenolic compounds were individually tested, none of them exhibited biological activity. Wfe concluded that the biological activity was associated with either the threshold levels of chemicals in the crude extracts or synergistic effect of sane chemicals. Similar observations were made by others, and it needs to be verified by further experimentation (17, 48). 

Alkylations of phenols with epichlorohydrin under PTC conditions and microwave irradiation were described twice in 1998. Subsequently, ring-opening reactions of the epoxide group were also performed using microwaves (Eqs. 20 and 21) [31, 32]. In the first catalytic synthesis of chiral glycerol sulfide ethers was described [31] in the second biologically active amino ethers were prepared [32],... 

Tripoli E, Giammanco M, Tabacchi G, Di Majo D, Giammanco S and La Guardia M. 2005. The phenolic compounds of olive oil structure, biological activity and beneficial effects on human health. Nutr Res Rev 18(1) 98—112. 

It should be noted that pharmacological vitamin E is not a free natural RRR-a-tocopherol or synthetic All rac a-tocopherol but its acetate ester. a-Tocopheryl acetate has the phenolic hydroxyl group blocked and therefore, is not a genuine antioxidant, but this compound is very rapidly hydrolyzed in vivo into a-tocopherol. It is interesting that the biological activity of a-tocopheryl acetate is the same as that of a-tocopherol in humans but significantly lower in rats [30]. ( A man is not a rat Professor KU Ingold.)... 

Hura T, Dubert F, Dabkowska T, Stupnicka-Rodzynkiewicz E, Stoklosa A, Lepiarczyk A (2006) Quantitative analysis of phenolics in selected crop species and biological activity of these compounds evaluated by sensitivity of Echinochloa crus-galli. Acta Physiol Plant 28 537-545... 

While the efficacy of these new, biologically active materials has been attributed (28,29) primarily to the presence of the fluoroalkoxy group, it is important to note that the need for more efficient syntheses of these and related materials still exists. For example, the syntheses of both the above materials involve multi-step, moderate yield processes in which the fluoroalkoxy group is introduced in the initial step of the sequence via reaction of a nucleophilic phenolate derivative with either a fluoroalkene ( ) or a triflate... 

In recent years, numerous applications of such peroxidase-catalyzed oxidative coupling of phenols and aromatic amines have been reported (Table 7). These peroxidase-catalyzed biotransformations lead to modified natural products with high biological activities [110-118]. Several examples have also been described for the oxidative coupling of phenols with peroxidases and other oxidative enzymes from a variety of fungal and plant sources as whole cell systems... 

Peroxidases have been used very frequently during the last ten years as biocatalysts in asymmetric synthesis. The transformation of a broad spectrum of substrates by these enzymes leads to valuable compounds for the asymmetric synthesis of natural products and biologically active molecules. Peroxidases catalyze regioselective hydroxylation of phenols and halogenation of olefins. Furthermore, they catalyze the epoxidation of olefins and the sulfoxidation of alkyl aryl sulfides in high enantioselectivities, as well as the asymmetric reduction of racemic hydroperoxides. The less selective oxidative coupHng of various phenols and aromatic amines by peroxidases provides a convenient access to dimeric, oligomeric and polymeric products for industrial applications. 

Biological. Bacterial degradation of 2-methylphenol may introduce a hydroxyl group producing 3-methylcatechol (Chapman, 1972). In phenol-acclimated activated sludge, metabolites identified include 3-methylcatechol, 4-methylresorcinol, methylhydroquinone, a-ketobutyric acid, dihydrox-ybenzaldehyde, and trihydroxytoluene (Masunaga et al, 1986). 

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