BHT butylated

Di-/ f2 -butyl-4-methylphenol, which is commonly known as BHT (butylated hydroxy toluene), is a widely used phenoHc antioxidant in the stabilization of oils, mbber, and polyolefins (44). BHT is also one of the few phenolic antioxidants approved by the FDA as a direct food additive where it is used to retard the oxidation of naturally occurring oils in food. 

To obtain maximum lifetime, the oxidants must not be lost during service. A major potential source of loss is the evaporation of the antioxidant. Evaporation is often observed with BHT (butylated hydroxytoluene), a monomeric phenol, and to avoid evaporation less volatile, higher molecular weight antioxidants are used (i.e. bisphenols). 

In addition lo its use in making resins and adhesives, phenol is also the starting material for the synthesis of chlorinated phenols and the food preservatives BHT (butylated hvdroxytoiuene) and BHA (butylated bydroxyanisole). Penta-chlorophenol, a widely used wood preservative, is prepared by reaction of phenol with excess CI2- The herbicide 2,4-D (2,4-dichlorophenoxyacetjc acid) is prepared from 2,4-dichlorophenol, and the hospital antiseptic agent hexa-chlorophene is prepared from 2,4,5-trichlorophenol. 

BHT (butylated hydroxytoluene) is sometimes added as an antioxidant preservative to keep the oils from going rancid. 

AA = amonium acetate. ACN = acetonitrile. BHT = butylated hydroxytoluene. CHjClj = dichloromethane. HEX = hexane. IS = internal standard. MeOH = methanol. RT = room temperature. TEA = triethylamine. TBME = tert-butyl methyl ether. THE = tetrahydrofuran. 

BCF Basophil chemotactic factor B-CFC Basophil colony-forming cell BCG Bacillus Calmette-Guerin BCNU l,3-bis(2-chloroethyl)-l-nitrosourea bFGF Basic fibroblast growth fiictor Bg Birbeck granules BHR Bronchial hyperresponsiveness BHT Butylated hydroxyroluene b.i.d. Bis in die (twice a day)... 

Oxidative addition of a silyl-protected 4-(bromomethyl)phenol precursor to (tme-da)Pd(II)Me2 (tmeda = tetramethylethylenediamine), followed by ethane reductive elimination, resulted in formation of the benzylic complex 16 (Scheme 3.10). Exchange of tmeda for a diphosphine ligand (which is better suited for stabilizing the ultimate Pd(0) QM complex), followed by removal of the protecting silyl group with fluoride anion, resulted in the expected p-QM Pd(0) complex, 17, via intermediacy of the zwitterionic Pd(II) benzyl complex. In this way a stable complex of p-BHT-QM, 17b, the very important metabolite of the widely used food antioxidant BHT20 (BHT = butylated hydroxytoluene) was prepared. Similarly, a Pd(0) complex of the elusive, simplest /)-QM, 17a, was obtained (Scheme 3.10). 

Note THF = tetrahydrofuran BHT = butylated hydroxytoluene, an antioxidant Camptothecin (CM) = causes inhibition of the DNA enzyme topoisomerase (Top 1) which induces DNA damage and apoptosis DHT = dihydrotestosterone PrEC = normal prostate stromal cells LNCaP, PC-3, DU-145 = neoplastic prostate epithelial cells (See Table 21.1). 

Synonyms BHT butylated hydroxytoluene DBPC 2,6-bis(l,l-dimethylethyl)-4-methyl-phenol... 

Antioxidants Ascorbic acid, BHA (butylated hydroxyanisole), BHT (butylated hydroxytoluene tocopherols)... 

Aromatic alcohols are called phenols. The simplest phenol, also called phenol, forms when a hydroxyl group replaces a hydrogen atom in the benzene ring. Phenol (carbolic acid) was used as an antiseptic in the 1800s. Today other phenol derivatives are used in antiseptic mouthwashes and in cleaning disinfectants such as Lysol. Phenols are easily oxidized, and this makes them ideal substances to use as antioxidants. By adding phenols such as BHT (butylated hydroxy toluene) and BHA (butylated hydroxy anisole) to food, the phenols oxidize rather than the food. 

Abbreviations. BHA, butylated hydi oxyanisole BHT, butylated hydroxytoluene EDTA, edetate calcium disodium. 

BHT, butylated hydroxytoluene BHA, butylated hydroxyanisole EDTA, ethylenediaminetetraacetic acid MeOH, methanol EtOH, ethanol 2-PrOH, 2-propanol BuOH, butanol MeCN, acetonitrile CHC13, chloroform CH2C12, dichloromethane (methylene chloride) THF, tetrahydrofuran DMF, dimethylformamide DMSO, dimethylsulfoxide MTBE, methyl tert-butyl ether. 

T Stijve. Gas chromatographic determination of butylated hydroxytoluene (BHT), butylated hydroxyanisole (BHA) and tert-butylhydroquinone (TBHQ) in milk products. Deutsch Lebensm Rund-sch 79 108-111, 1983. 

Aqua, caprylic/capric triglyceride, Avene aqua, paraffinum liq-uidum, propylene glycol, glyceryl stearate, PEG-100 stearate, squa-lane, BHT, butyl paraben, C13-14 isoparaffin, carbomer, disodium EDTA, laureth-7, phenoxyethanol, polyacrylamide, propylparaben, Cl 17200, retinal, tocopheryl glucoside and triethanolamine. 

Further oxidation of these products can result in the consumption of many equivalents of oxidant for each molecule of DBP. This is the chemistry by which antioxidants protect many commercial products from spoilage or material damage by oxidation (20). Antioxidants such as DBP, and the more familiar BHT (butylated hydroxy toluene or 2,6-di-(t-butyl)-4-methyl phenol), are used very widely, so these compounds and their oxidation products are widely distributed in the environment (21). 

Notes LOD, limit of detection MeOH, methanol EtOH, ethanol ACN, acetonitrile MTBE, methyl tert-butyl ether DCM, dichloromethane THF, tetrahy-drofuran KOH, potassium hydroxide SFE, supercritical fluid extraction MS, mass spectrometry HPLC, high-performance liquid chromatography DAD, diode array detector PDA, photodiode array detector FD, fluorescence detector ECD, electrochemical detector ESI, electrospray ionization APCI, atmosphere pressure chemical ionization TLC, thin layer chromatography FAB, fast atom bombardment NMR, nuclear magnetic resonance BHT, butylated hydroxytoluene SPE, solid phase extraction. 

Department of Biochemistry, Cleveland Clinic Foundation, Cleveland, OH 44106 Selenium, vitamin C, vitamin E, BHT (butylated... 

Oxidation is also the main cause of perfume instability in poor-quality toilet soaps here it is caused by the fatty acid peroxides formed at the stage of incipient rancidity. Perfumes may to some extent be protected against oxidation by the incorporation of 1% to 2% of an antioxidant such as BHT (butylated hydroxy toluene) into the perfume oil. 

Compounds that are in direct contact with air when in the final product, for example as in powder products or in soap, are particularly at risk from oxidation, and the head space above the product is likely therefore to become rich in the breakdown products of oxidation. For this reason the packaging usually allows for a certain amount of "breathing" so as to let these "off-odors" escape rather than their being reabsorbed into the product. A number of products exist, generally classed as antioxidants, for example, BHT (butyl hydroxytoluene), that help to inhibit these oxidation reactions. These antioxidants are often added to citrus oils, or to compounds to prolong their shelf life, or to the final product. 

Explain why a small amount of BHT (butylated hydroxy toluene) is often added to styrene before it is sold for use in a research laboratory. 

The fert-butyl group (t-butyl or f-Bu) group has three methyl groups joined to the same carbon atom. Two t-Bu groups are found in BHT ( butylated hydroxy toluene ), an antioxidant added to some processed foods. 

Ratio = blend ratio soybean oil fatty acid methyl esters (SME) in low-sulfur (<500ppm) No. 2 petrodiesel (LSD) where BO is 0% SME and B20 contains 20 vol% SME BHA = butylated hydroxyanisole BHT = butylated hydroxytoluene TBHQ = tert-butylhydroquinone. 

Figure 1.1. Selected Synthetic Antioxidants. BHT = Butylated hydroxytoluene TBHQ = ferf-butylhydroxyquinone BHA = butylated hydroxyanisole TBHT = ferf-butyl hydroxytoluene Trolox = 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid.

Gum bases normally contain a permitted antioxidant. Typically, buty-lated hydroxytoluene (BHT), butylated hydroxyanisole (BHA) or toco-pherols are used. The reason that these substances are used is that the gum base is subject to oxidation, and antioxidants work because they act as free-radical traps. Oxidation normally occurs via a free-radical mechanism, and because of this, oxidation is a zero free energy process and relatively unaffected by the ambient temperature. 

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