CHEMISTRY OF HOP CONSTITUENTS: XXII. PROTON MAGNETIC RESONANCE SPECTROSCOPY OF<i>ISO</i>HUMULONE A

Burton, J. S.; Stevens, Roger; Elvidge, J. A.

doi:10.1002/j.2050-0416.1964.tb02002.x

Cited by 11 publications

(8 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Each α-acid yields in fact two iso-α-acids as these occur as diastereoisomers in their cis and trans forms (35). Although the isomerization process has been known since the late 1920s (36) and has been extensively studied by many research groups over the years (37)(38)(39)(40)(41)(42)(43)(44)(45)(46)(47), the configuration of the iso-α-acids had remained speculative. In a recent study (48), the absolute configuration of the cis and trans iso-α-acids was determined by X-ray crystallography.…”

Section: Soft Resinsmentioning

confidence: 99%

Humulus lupulus- a story that begs to be told. A review

Schönberger²,

et al. 2014

View full text Add to dashboard Cite

The hop cones of the female plant of the common hop species Humulus lupulus L. are grown almost exclusively for the brewing industry. Only the cones of the female plants are able to secrete the fine yellow resinous powder (i.e. lupulin glands). It is in these lupulin glands that the main brewing principles of hops, the resins and essential oils, are synthesized and accumulated. Hops are of interest to the brewer since they impart the typical bitter taste and aroma to beer and are responsible for the perceived hop character. In addition to the comfortable bitterness and the refreshing hoppy aroma delivered by hops, the hop acids also contribute to the overall microbial stability of beer. Another benefit of the hop resins is that they help enhance and stabilize beer foam and promote foam lacing. In an attempt to understand these contributions, the very complex nature of the chemical composition of hops is reviewed. First, a general overview of the hop chemistry and nomenclature is presented. Then, the different hop resins found in the lupulin glands of the hop cones are discussed in detail. The major hop bitter acids (α-and β-acids) and the latest findings on the absolute configuration of the cis and trans iso-α-acids are discussed. Special attention is given to the hard resins; the known δ-resin is reviewed and the ε-resin is introduced. Recent data on the bittering potential and the antimicrobial properties of both hard resin fractions are disclosed. Attention is also given to the numerous essential oil constituents as well as their contributions to beer aroma. In addition to the aroma contribution of the well-known essential oil compounds, a number of recently identified sulfur compounds and their impact on beer aroma are reviewed. The hop polyphenols and their potential health benefits are also addressed. Subsequently, the importance of hops in brewing is examined and the contributions of hops to beer quality are explained. Finally, the beer and hop market of the last century, as well as the new trends in brewing, are discussed in detail. Hop research is an ever growing field of central importance to the brewing industry, even in areas that are not traditionally associated with hops and brewing. This article attempts to give a general overview of the different areas of hop research while assessing the latest advances in hop science and their impact on brewing.

show abstract

Section: Soft Resinsmentioning

confidence: 99%

Humulus lupulus- a story that begs to be told. A review

Schönberger²,

et al. 2014

View full text Add to dashboard Cite

show abstract

“…Before isohumulone was resolved into its two isomers it was possible to predict from its proton magnetic resonance spectrum and from a study of the spectra of humulinic acids A and B that it was a mixture of two stereoisomers. The major isomer (about 60% of the mixture) had humulinic acid B stereochemistry (CII) and the other that of humulinic acid A (CIII) (73).…”

Section: Ch3mentioning

confidence: 99%

The Chemistry of Hop Constituents

Stevens¹

1967

Chem. Rev.

121

View full text Add to dashboard Cite

“…The isomerization process has been recognized for over 80 years,6–8 yet the absolute configuration of carbon atoms 4 and 5 of the iso-α-acids (Scheme 1) have remained speculative. For the most predominant member of the iso-α-acid family, isohumulone, the cis and trans isomerization products, differing at carbon atom 4, were described preliminarily almost 50 years ago (Scheme 1).…”

mentioning

confidence: 99%