2,5-Di-tert-butylhydroquinone

Description

2,5-Di-tert-butylhydroquinone, also known as 2,5-TBHQ or DTBHQ, belongs to the class of organic compounds known as phenylpropanes. These are organic compounds containing a phenylpropane moiety. It is a phenol derivative containing 2 phenol groups and 2 alkyl groups, each consisting of three methyl groups.

Chemical Properties

cream or pale brown solid

Uses

2,5-Di-tert-butylhydroquinone is the oxidation substrate used to measure the catalytic activity of the copper(II) enzyme-like catalysts.

Definition

ChEBI: A member of the class of hydroquinones that is benzene-1,4-diol substituted by tert-butyl groups at position 2 and 5.

General Description

Mobilizes Ca²⁺ specifically from the Ins(1,4,5)P₃-sensitive Ca²⁺ stores by inhibiting microsomal and sarcoplasmic reticulum Ca²⁺-ATPase activity. Does not affect mitochondrial Ca²⁺ fluxes or plasma membrane Ca²⁺/Mg²⁺ ATPase activity. Useful for the study of endomembrane Ca²⁺ stores and plasma membrane Ca²⁺ permeability pathways.

Biological Activity

A selective inhibitor of endoplasmic reticulum Ca 2+ -ATPase.

Biochem/physiol Actions

2,5-Di-tert-butylhydroquinone specifically inhibits the sarcoplasmic reticulum (SR) Ca2+ uptake in the rat ventricle.

Synthesis

General procedure for the synthesis of 2,5-di-tert-butylhydroquinone from 2,5-di-tert-butyl-1,4-benzoquinone: To a Teflon tubular glass ampoule with stopper was added about 4.8 mL volume of 0.166 mmol 2,5-di-tert-butyl-1,4-benzoquinone, a stirring bar, and 0.25 mL of a toluene solution containing 0.5 mg iPrPCPIrH4. Subsequently, the solution was subjected to two freeze-pump-thaw degassing cycles and sealed under a 1 atm hydrogen atmosphere. The sealed vessel was placed in an aluminum heating block, heated at the indicated temperature and stirred for the specified time. Upon completion of the reaction, volatiles were removed by depressurization until only a few μL of toluene remained, and the ampoule was quickly sealed. Finally, 0.5 mL of THF-d8 was added and the solution was transferred to an NMR tube for NMR analysis.

Purification Methods

Crystallise the hydroquinone from *C6H6 or AcOH. [Beilstein 6 III 4741.]

References

[1]. hasséssian h, vaca l, kunze dl. blockade of the inward rectifier potassium current by the ca(2+)-atpase inhibitor 2',5'-di(tert-butyl)-1,4-benzohydroquinone (bhq). br j pharmacol, 1994, 112(4): 1118-1122.
[2]. fusi f, gorelli b, valoti m, et al. effects of 2,5-di-t-butyl-1,4-benzohydroquinone (bhq) on rat aorta smooth muscle. eur j pharmacol, 1998, 346(2-3): 237-243.
[3]. fusi f, saponara s, gagov h, et al. 2,5-di-t-butyl-1,4-benzohydroquinone (bhq) inhibits vascular l-type ca(2+) channel via superoxide anion generation. br j pharmacol, 2001, 133(7): 988-996.
[4]. jan cr, ho cm, wu sn, et al. mechanism of rise and decay of 2,5-di-tert-butylhydroquinone-induced ca2+ signals in madin darby canine kidney cells. eur j pharmacol, 1999, 365(1): 111-117.