Related Experiment Video
Updated: Feb 12, 2026

DNAzyme-dependent Analysis of rRNA 2’-O-Methylation
Published on: September 16, 2019
Identification of a precursor of 2-mercapto-3-methyl-1-butanol in beer
Shigekuni Noba1, Nana Yako1, Hiroaki Sakai2
1Research Laboratories for Alcohol Beverages, Asahi Breweries Ltd., 1-21 Midori 1-chome, Moriya-shi, Ibaraki 302-0106, Japan.
Abstract:
2-Mercapto-3-methyl-1-butanol (2M3MB) imparts an onion-like off-flavor to beer and is believed to result from the hot aeration of brewer's wort. However, little has been reported regarding the mechanism of formation of 2M3MB. This paper investigates the precursors of 2M3MB formed during the brewing process. Our study of a cysteine conjugate as a precursor showed its negligible contribution to the formation of 2M3MB. The 2M3MB precursor was found to be a volatile compound because 2M3MB was formed in the distillate of hop extract. The precursor was purified through distillation, column chromatography, and preparative gas chromatography, and the 2M3MB-producing potential was measured as an index for estimating the concentration of the precursor. The accurate mass of the precursor was measured using gas chromatography coupled to quadrupole-time-of-flight-mass spectrometry (GC/QTOF). The molecular structure was identified from the product ion spectra by GC/QTOF to be 2,3-epoxy-3-methylbutanal.
Related Concept Videos
Predicting Products: SN1 vs. SN2
With increased substitution on the alkyl halide,...
ortho–para-Directing Activators: –CH3, –OH, –⁠NH2, –OCH3
1° Amines to Diazonium or Aryldiazonium Salts: Diazotization with NaNO2 Overview
The nitrous acid is unstable. Hence, it is formed in situ from a solution of sodium nitrite and cold aqueous acids such as hydrochloric or sulfuric acid. In an acidic solution, the –OH group of nitrous acid undergoes protonation to give oxonium ion, followed by...
1° Amines to Diazonium or Aryldiazonium Salts: Diazotization with NaNO2 Mechanism
UV–Vis Spectroscopy: Beer–Lambert Law
Mitochondrial Precursor Proteins
Most of the mitochondrial...

