Acids 2-hydroxytoluene

Synonyms o-cresylic acid 2-hydroxytoluene 2-methylphenol ortho-cresol. 

Chemical Designations - Synonyms Cresylic Acids Hydroxytoluenes Methylphenols Oxytoluenes Tar Acids Chemical Formula CH3C3 H4OH. 

Cresols Cresylic Acids Hydroxytoluenes Methylphenold Oxytoluenes Tar Acids... 

Cresols — (i) Chemical Designations — Synonyms Cresylic Acids Hydroxytoluenes Methylphenols Oxy-toluenes Tar Acids Chemical Formula CHjCj H OH (ii) Observable Characteristics— Physical State (as normally shipped) Liquid or solid Color Colorless or dark to yellow Odor Sweet, tarry (iii) Physical and Chemical Properties — Physical State at 15 °C and I atm. Liquid Molecular Weight 108.13 Boiling Pmm at 1 atm. > 350, >177, >450 Freezing Point Not pertinent Critical Temperature Not pertinent Critical Pressure Not pertinent Specific Gravity 1.03 - 1.07 at 20" C (liquid) Vapor (Gas) Density Not pertinent Ratio of Specific Heats of Vapor (Gas) 1.073 Latent Heat of Vaporization (est.) 200, 110, 4.6 Heat of Combustion ... 

Antioxidants (qv) have a positive effect on oils when present in the proper concentration. Sterols and tocopherols, which are natural antioxidants, may be analy2ed by gas-Hquid chromatography (glc), high performance Hquid chromatography (hplc), or thin-layer chromatography (tic). Synthetic antioxidants maybe added by processors to improve the performance or shelf life of products. These compounds include butylatedhydroxyanisole (BHA), butylated hydroxytoluene (BHT), / fZ-butyUiydroquinone (TBHQ), and propyl gallate. These materials may likewise be analy2ed by glc, hplc, or tic. Citric acid (qv), which functions as a metal chelator, may also be deterrnined by glc. 

The FCC is to food-additive chemicals what the USP—NF is to dmgs. In fact, many chemicals that are used in dmgs also are food additives (qv) and thus may have monographs in both the USP—NF and in the FCC. Examples of food-additive chemicals are ascorbic acid [50-81-7] (see Vitamins), butylated hydroxytoluene [128-37-0] (BHT) (see Antioxidants), calcium chloride [10043-52-4] (see Calcium compounds), ethyl vanillin [121-32-4] (see Vanillin), ferrous fumarate [7705-12-6] and ferrous sulfate [7720-78-7] (see Iron compounds), niacin [59-67-6] sodium chloride [7647-14-5] sodium hydroxide [1310-73-2] (see lkaliand cm ORiNE products), sodium phosphate dibasic [7558-79-4] (see Phosphoric acids and phosphates), spearmint oil [8008-79-5] (see Oils, essential), tartaric acid [133-37-9] (see Hydroxy dicarboxylic acids), tragacanth [9000-65-1] (see Gums), and vitamin A [11103-57-4]. 

PTMEG is a polymeric ether susceptible to both thermal and oxidative degradation. It usually contains 300—1000 ppm of an antioxidant such as 2,6-di-/ f2 -butyl-4-hydroxytoluene (BHT) to prevent oxidation under normal storage and handling conditions. Thermal decomposition in an inert atmosphere starts at 210—220°C (410—430°E) with the formation of highly flammable THE. In the presence of acidic impurities, the decomposition temperature can be significantly reduced contact with acids should therefore be avoided, and storage temperatures have to be controlled to prevent decomposition to THF (261). 

As metal ions catalyze peiroxidation reactions, glass-distilled water should be used and chelating agents can be added to the medium. (5) The dispersions should not be exposed to y irradiation. (6) Antioxidant can be added to the system. a-Tocopherol, buty-lated hydroxytoluene, butyl hydroxyanisole, and ascorbic acid have been proposed as antioxidants. 

Rgure 2.3 The antioxidant activity of butyiated hydroxytoluene in the presence of exogenous iipid hydroperoxides. The oxidation of LDL was monitored by measuring the increase in absorbance at 234 nm as described in Fig. 2.2 and the lag phase (time before the phase of maximum rate of oxidation) estimated as described by Esterbauer et at. (1989). Samples of LDL were supplemented with the cortcentrations of 13-hydroperoxyoctadecanoic acid (13-HPODE) indicated and in the presence of 3 fM BHT. The lag phase in the absence of BHT for this preparation of LDL was 48 min. 

It should be mentioned that the Food Additives Analytical Manual (FAAM) [75] provides analysts with FDA evaluated methodology (partly subjected to collaborative study) needed to determine compliance with food additive regulations, including procedures for indirect food additives, such as butylated hydroxy-anisole (BHA), butylated hydroxytoluene (BHT), t-butylhydroxyquinone (TBHQ), dilaurylthiopropionate (DLTDP), fatty acid methyl esters (FAME), sodium benzoate, sorbitol, and others. 

The selection of an appropriate antioxidant depends on factors such as stability, toxicity, efficiency, odor, taste, compatibility with other ingredients, and distribution phenomena between the two phases. Antioxidants that give protection primarily in the aqueous phase include sodium metabisulfite, ascorbic acid, thioglycerol, and cysteine hydrochloride. Oil-soluble antioxidants include lecithin, propyl gal-late, ascorbyl palmitate, and butylated hydroxytoluene. Vitamin E has also been used, but its virtue as a natural antioxidant has been the subject of some controversy. 

Creosol (also called 2-methoxy-jb-cresol, 4-methylguaiacol, and 3-methoxy-4-hydroxytoluene) has been obtained by the fractionation of beach creosote tar,4 by the reduction of vanillin by electrolytic methods,6 6 by hydrogen and palladium on charcoal or barium sulfate,7 8 with hydrazine,9 and by amalgamated zinc and hydrochloric acid.3 10 11 It has also been prepared by methyl-ation of 4-methylcatechol with methyl iodide 12 13 or with methyl sulfate 14 and is reported to be formed by the distillation of the calcium salt of 3-methoxy-4-hydroxyphenylacetic acid.16... 

Bromo-2-ethoxyethane, 23, 32 3-Bkomo-4-hydroxytoluene, 23,11 -Bromoisocaproic ACID, 21, 74 a-BROMOISOvaleric acid, 20, 106 Bromomesitylene, 21, 77... 

Chemically carotenoids have conjugated double bonds that render them liable to oxidation. This tendency to oxidation can be diminished by adding antioxidants to the product. In the sort of product where natural colours are used suitable antioxidants would be tocopherols or ascorbic acid. Chemical antioxidants such butylated hydroxytoluene might be suitable technically but would not fit the image of an allnatural product. Ascorbic acid could be declared as vitamin C rather than as an antioxidant. Oxidation can be started by exposure to light and so this is best avoided. Carotenoids are generally stable to heat. The levels required can be as low as 10 ppm. P-Carotene is available as a nature identical form. 

Annex III lays down the conditions of use for permitted preservatives and antioxidants, with lists of foods and maximum levels in each case. Part A lists the sorbates, benzoates and p-hydroxybenzoates, E 200-E 219 part B lists sulphur dioxide and the sulphites, E 220-E 228 part C lists other preservatives with their uses, including nisin, dimethyl dicarbonate and substances allowed for surface treatment of certain fruits, E 249 potassium nitrite, E 250 sodium nitrite, E 251 sodium nitrate and E 252 potassium nitrate, E 280-E 283 propionic acid and the propionates part D lists the antioxidants E 320 butylated hydroxyanisole (BHA), E 321 butylated hydroxytoluene (BHT), E 310 propyl gallate, E 311 octyl gallate, E 312 dodecyl gallate, E 315 eiythorbic acid and E 316 sodium erythorbate. 

Figure 5. Inhibitory effect of NO on Fe -induced lipid peroxidation. Shown is the decreased generation of an oxidative marker (thiobarbituric acid reactive substances, TBARS) as a result of 0.9 iM NO. HL-60 cells (5 x loVral) were placed in an O2 monitor and at the designated time points, butylated hydroxytoluene was added and samples were quick frozen for determination of TBARS. The values represent the mean and standard error of 3-5 independent determinations. Also shown for comparison is the residual concentration of O2 after exposure to the the same conditions. This shows a decrease in utilization of O2 in the presence of NO. We conclude that NO reduces TBARS, and the percent inhibition is similar to the poeent inhibition of O2 consumption. (Modified from our data in Kelley, E.E., Wagner, B.A., Buettner, G.R., and Bums, C.P., 1999, Arch. Biochem. Biophys. 370 97-104).

Note May contain acetic acid, 2-methyl-l,3-dioxolane, and bis(2-chloroethyl) ether as impurities. May be inhibited with butylated hydroxytoluene. 

Synonyms AI3-00137 BRN 0506917 CCRIS 646 2-Cresol o-Cresol o-Cresylic acid EINECS 202-423-8 FEMA No. 3480 l-Hydroxy-2-methylbenzene 2-Hydroxytoluene o-Hydroxytoluene 2-Methylhydroxybenzene o-Methylhydroxybenzene o-Methylphenol o-Methylphenylol NSC 23076 Orthocresol o-Oxytoluene RCRA waste number U052 2-Toluol o-Toluol UN 2076. 

Synonyms AI3-00150 BRN 1305151 CCRIS 647 4-Cresol p-Cresol p-Cresylic acid EINECS 203-398-6 FEMA No. 2337 l-Hydroxy-4-methylbenzene p-Hydroxytoluene 4-Hydroxytoluene p-Kresol l-Methyl-4-hydroxybenzene 4-Methylhydroxybenzene p-Methyl-hydroxybenzene p-Methylphenol NSC 3696 4-Oxytoluene p-Oxytoluene Paracresol Paramethylphenol RCRA waste number U052 4-Toluol p-Toluol p-Tolyl alcohol UN 2076. 

Hydroxytoluene, see Toluene a-Hydroxy-p-toluic acid, see o-Xylene, ro-Xylene,... 

Synonyms Cresylic acid tricresol methyl-phenol o-cresol m-crtsoV, p-cresol hydroxytoluene... 

An important antioxidant for many products is butylated hydroxytoluene (BHT), more properly named 4-methyl-2,6-di-t-butylphenol. Acid-catalyzed electrophilic aromatic substitution of a t-butyl cation at the activated positions ortho to the hydroxy group of /)-cresol yields this product, p-Cresol is obtained from coal tar or petroleum. 

Antihepatotoxic activity. A mixture of the methanol-insoluble fraction of the dried resin, fresh garlic, curcumin, ellagic acid, butylated hydroxytoluene, and butylated hydroxyanisole, administered by gastric intubation to ducklings at a dose of 10 mg/ani-mal, was active vs aflatoxin Bl-induced hepatotoxicity " . ... 

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