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Characterization of reduced iso-α-acids derived from hops (Humulus lupulus) by NMR

✍ Scribed by Lars I. Nord; Steen Bech Sørensen; Jens Ø. Duus

Book ID: 102525916
Publisher: John Wiley and Sons
Year: 2003
Tongue: English
Weight: 295 KB
Volume: 41
Category: Article
ISSN: 0749-1581
DOI: 10.1002/mrc.1234

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✦ Synopsis

Abstract

Reduced forms of iso‐α‐acids (isohumulones), used in modern beer brewing were separated and characterized by ^1^H and ^13^C NMR spectroscopy. Components from mixtures of rho‐iso‐α‐acids, tetrahydro‐iso‐α‐acids, and hexahydro‐iso‐α‐acids were isolated using high‐performance liquid chromatography (HPLC) and analyzed by use of one‐ and two‐dimensional NMR experiments. The data presented assign the identities of the main peaks in the HPLC traces for the reduced iso‐α‐acids. Previous tentative assignments regarding the cis and trans configurations and the structures of the acyl residues of the reduced iso‐α‐acids were confirmed and extensive NMR assignments were made. Furthermore, the previously unknown stereochemistry in the C‐4 side‐chain of the rho‐ and hexahydro‐iso‐α‐acids was assigned. Copyright © 2003 John Wiley & Sons, Ltd.

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