title: Pharmacokinetics of reduced iso-α-acids in volunteers following clear bottled beer consumption.
abstract: Reduced iso-α-acids (reduced IAA) consisting of the rho-, tetrahydro- and hexahydro-IAA groups (RIAA, TIAA and HIAA, respectively) are ingredient congeners specific to beer and generally found in clear and also occasionally green bottled beer. Concentrations of reduced IAA were determined in the blood and urine of five volunteers over 6h following the consumption of small volumes of beer containing each of the reduced IAA. The reduced IAA were absorbed and bioavailable with peak concentrations at 0.5h followed by a drop of generally fivefold by 2h. Preliminary pharmacokinetics of these compounds in humans shows relatively small inter-individual differences and an estimated short half-life varying between ∼38 and 46min for the three groups. Comparison of RIAA analyte ratios within the group indicate that some analytes eliminate relatively faster than others and the formation of metabolite products was observed. Preliminary urine analysis showed only unmodified RIAA analytes were detectable throughout 6h and suggests extensive phase I metabolism of TIAA and HIAA analytes. In authentic forensic casework where clear or green bottled beers are consumed, the identification of reduced IAA groups may provide a novel method to target ingredient congeners consistent with beer ingestion and suggest the type of beer consumed.
authors.affiliation: Department of Forensic Medicine, Monash University, Southbank, Victoria, Australia; Victorian Institute of Forensic Medicine, Southbank, Victoria, Australia.
authors.forename: Luke N
authors.initials: LN
authors.lastname: Rodda
authors.affiliation: Department of Forensic Medicine, Monash University, Southbank, Victoria, Australia; Victorian Institute of Forensic Medicine, Southbank, Victoria, Australia.
authors.forename: Dimitri
authors.initials: D
authors.lastname: Gerostamoulos
authors.affiliation: Department of Forensic Medicine, Monash University, Southbank, Victoria, Australia; Victorian Institute of Forensic Medicine, Southbank, Victoria, Australia. Electronic address: olaf.drummer@monash.edu.
authors.forename: Olaf H
authors.initials: OH
authors.lastname: Drummer
mesh_terms: D000328:Adult; D001515:Beer; D002851:Chromatography, High Pressure Liquid; D053138:Cyclohexenes / Q000097:blood* / Q000652:urine*; D005260:Female; D053593:Forensic Toxicology; D005898:Glass; D006801:Humans; D027582:Humulus / Q000737:chemistry*; D007536:Isomerism; D008297:Male; D013058:Mass Spectrometry; D013729:Terpenes / Q000097:blood* / Q000652:urine*
chemical_list: D053138:Cyclohexenes; D013729:Terpenes; C007966:humulon
keywords: Alcohol congener analysis; Beer; Blood; Pharmacokinetics; Reduced iso-α-acids; Urine