The most important studies on butylated hydroxytoluene with reference to its therapeutic properties.

Donepezil-butylated hydroxytoluene (BHT) hybrids as Anti-Alzheimer's disease agents with cholinergic, antioxidant, and neuroprotective properties.
Cai P, Fang SQ, Yang HL, Yang XL, Liu QH, Kong LY, Wang XB.
Eur J Med Chem. 2018 Sep 5;157:161-176. doi: 10.1016/j.ejmech.2018.08.005. Epub 2018 Aug 4

Understanding the chemistry behind the antioxidant activities of butylated hydroxytoluene (BHT): a review.
Yehye WA, Rahman NA, Ariffin A, Abd Hamid SB, Alhadi AA, Kadir FA, Yaeghoobi M
Eur J Med Chem. 2015 Aug 28;101:295-312. doi: 10.1016/j.ejmech.2015.06.026.

A reappraisal of the proposed metabolic and antioxidant actions of butylated hydroxytoluene (BHT) in the liver.
Castro LDS, Bracht L, Comar JF, Peralta RM, Bracht A.
J Biochem Mol Toxicol. 2017 Aug;31(8). doi: 10.1002/jbt.21924. Epub 2017 May 29.

Pre-freezing Treatment with Butylated Hydroxytoluene and Cholesterol-loaded Methyl-β-cyclodextrin Improves Quality of Cryopreserved Boar Semen.
Baishya SK, Biswas RK, Govindasamy K, Deka BC, Sinha S, Singh M.
Cryo Letters. 2018 Sep/Oct;39(5):336-344.

Butylated hydroxytoluene induces type-V collagen and overexpression of remodeling genes/proteins in experimental lung fibrosis.
Martins V, Teodoro WR, Velosa APP, Andrade P, Farhat C, Fabro AT, Capelozzi VL.
Histol Histopathol. 2018 Oct;33(10):1111-1123. doi: 10.14670/HH-18-010. Epub 2018 Jun 5.

Migration studies of butylated hydroxytoluene, tributyl acetylcitrate and dibutyl phthalate into food simulants.
García Ibarra V, Sendón R, García-Fonte XX, Paseiro Losada P, Rodríguez Bernaldo de Quirós A.
J Sci Food Agric. 2019 Mar 15;99(4):1586-1595. doi: 10.1002/jsfa.9337. Epub 2018 Oct 17.

Estrogenic and anti-estrogenic activity of butylparaben, butylated hydroxyanisole, butylated hydroxytoluene and propyl gallate and their binary mixtures on two estrogen responsive cell lines (T47D-Kbluc, MCF-7).
Pop A, Drugan T, Gutleb AC, Lupu D, Cherfan J, Loghin F, Kiss B.
J Appl Toxicol. 2018 Jul;38(7):944-957. doi: 10.1002/jat.3601. Epub 2018 Feb 19.

Dietary butylated hydroxytoluene improves lipid metabolism, antioxidant and anti-apoptotic response of largemouth bass (Micropterus salmoides).
Yu LL, Yu HH, Liang XF, Li N, Wang X, Li FH, Wu XF, Zheng YH, Xue M, Liang XF.
Fish Shellfish Immunol. 2018 Jan;72:220-229. doi: 10.1016/j.fsi.2017.10.054. Epub 2017 Nov 7.

Preparation of steppogenin and ascorbic acid, vitamin E, butylated hydroxytoluene oil-in-water microemulsions: Characterization, stability, and antibrowning effects for fresh apple juice.
Tao J, Zhu Q, Qin F, Wang M, Chen J, Zheng ZP.
Food Chem. 2017 Jun 1;224:11-18. doi: 10.1016/j.foodchem.2016.12.045. Epub 2016 Dec 18.

2,6-di-tert-butyl-p-cresol (BHT, Butilidrossitoluene) a chemical compound, a derivative of phenol.

The name describes the structure of the molecule:

• 2,6-di Indicates the presence of two substituents attached to the benzene ring at positions 2 and 6.
• tert-butyl refers to tertiary butyl groups, which are the substituents attached to the benzene ring. A tert-butyl group is a functional group with the formula -C(CH₃)₃.
• p-cresol is the base molecule to which the tert-butyl groups are attached. Cresols are organic compounds that are methylphenols. The prefix 'p-' indicates that the hydroxyl group (-OH) is attached to the benzene ring in the para position, opposite the tert-butyl groups.

The synthesis process takes place in different steps:

• Preparation. The raw materials are p-cresol (a phenol) and isobutene (a hydrocarbon).
• Alkylation. p-cresol is reacted with isobutene in the presence of a catalyst, such as sulphuric acid, at a controlled temperature and pressure. This process is known as alkylation and attaches the tert-butyl groups to the p-cresol molecule.
• Separation. The reaction mixture is then separated to isolate the 2,6-di-tert-butyl-p-cresol by various methods, including distillation, in which the mixture is heated and the components that vaporise at different temperatures are separated.
• Purification.  The separated product is purified to remove any unreacted materials and by-products by processes such as washing, filtration and drying.
• Quality control. The final product is tested to ensure that it meets the necessary quality standards.

What it is for and where

2,6-di-tert-butyl-p-cresol is used in the food, cosmetic and pharmaceutical fields for its antioxidant properties. It is in fact a preservative.

Cosmetics

Antioxidant agent. Ingredient that counteracts oxidative stress and prevents cell damage. Free radicals, pathological inflammatory processes, reactive nitrogen species and reactive oxygen species are responsible for the ageing process and many diseases caused by oxidation.

Fragrance. It plays a decisive and important role in the formulation of cosmetic products as it provides the possibility of enhancing, masking or adding fragrance to the final product, increasing its marketability. It is able to create a perceptible pleasant odour, masking a bad smell. The consumer always expects to find a pleasant or distinctive scent in a cosmetic product. 

Food

Used to prevent the rancidity of oils and fats in foods.

Packaging 

Used in food packaging to prevent the oxidation of the contained food.

Fuels and Lubricants

Added to fuels and lubricants to prevent deposit formation.

Veterinary Medicine

Used in some veterinary products as preservative.

Safety

The use of BHT in food has been a matter of some debate due to potential health concerns. However, regulatory agencies like the US Food and Drug Administration (FDA) have deemed it generally recognized as safe (GRAS) in low amounts. Some studies have shown potential risks with high doses, but the concentrations typically used in food are much lower.

Alternative: Its sister compound, butylated hydroxyanisole (BHA), has similar properties and is also used in food preservation.

Environmental Concerns: BHT is not easily biodegradable, and there have been some concerns about its persistence in the environment.

The most relevant studies on this chemical compound have been selected with a summary of their contents:

2,6-di-tert-butyl-p-cresol studies

• Molecular Formula: C₁₅H₂₄O
• Linear Formula [(CH₃)₃C]₂C₆H₂(CH₃)OH
• Molecular Weight: 220.356 g/mol
• UNII: 1P9D0Z171K
• CAS: 128-37-0  950-56-1  25377-21-3  102962-45-8  42615-30-5  50356-19-9  50641-99-1  52683-46-2  53571-70-3  58500-82-6  83047-16-9  97123-41-6  36631-28-4  290348-23-1  259752-53-9  1394965-02-6  1456709-94-6  2055662-96-7  338986-13-3
• EC Number: 204-881-4  246-911-9
• FEMA Number: 2184

Synonyms:

• Butylated hydroxytoluene
• Butylhydroxytoluene
• 2,6-Di-tert-butyl-p-cresol
• 2,6-Di-t-butyl-4-methylphenol
• Ionol
• DBPC
• Antioxidant 4K
• Sumilizer BHT
• 2,6-Di-tert-butyl-4-cresol
• Phenol, 2,6-bis(1,1-dimethylethyl)-4-methyl-
• 2,6-ditert-butyl-4-methylphenol
• Di-tert-butyl-p-cresol
• 4-Methyl-2,6-tert-butylphenol
• Topanol O
• Topanol OC
• Antioxidant 30
• Nonox TBC
• Tenox BHT
• Chemanox 11
• Ionol 1
• Agidol
• Catalin CAO-3
• Advastab 401
• 2,6-Di-tert-butyl-1-hydroxy-4-methylbenzene
• 2,6-Di-tert-butyl-p-methylphenol
• Vanlube PC
• Antioxidant DBPC
• Sustane BHT
• Tenamene 3
• Vanlube PCX
• Dibunol
• Stavox
• BHT
• Ionol CP
• Impruvol
• Topanol
• Dalpac
• Deenax
• Ionole
• Vianol
• Antioxidant KB
• 3,5-Di-tert-butyl-4-hydroxytoluene