has role is protonated form of has functional parent thiopental CHEBI:102166 A barbiturate, the structure of which is that of 2-thiobarbituric acid substituted at C-5 by ethyl and <em>sec</em>-pentyl groups. barbiturates 2-thiobarbituric acid anticonvulsant xenobiotic sedative intravenous anaesthetic racemate thiopental(1-) neuroprotective agent ophthalmology drug environmental contaminant drug allergen