NMR assignment of iso-α-acids from isomerised extracts of humulus lupulus L. cones

Iso-α-acids are known to contribute to the characteristic bitter taste of beer. Six iso-α-acids were isolated from a carbon dioxide extract of the cones of Humulus lupulus L. by centrifugal partition chromatography followed by separation through β- cyclodextrin binding. This method overcame the lo...

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Main Authors:	Khatib, Alfi, Wilson, Erica G., Kim, Hye Kyong, Supardi, Moses, Choi, Young Hae, Verpoorte, Robert
Format:	Article
Language:	English
Published:	John Wiley & Sons, Ltd. 2007
Subjects:	QD Chemistry
Online Access:	http://irep.iium.edu.my/33742/ http://irep.iium.edu.my/33742/ http://irep.iium.edu.my/33742/ http://irep.iium.edu.my/33742/1/Khatib_et_al%2C_2007._Phytochem._Anal..pdf

id	iium-33742
recordtype	eprints
spelling	iium-337422014-01-06T03:29:21Z http://irep.iium.edu.my/33742/ NMR assignment of iso-α-acids from isomerised extracts of humulus lupulus L. cones Khatib, Alfi Wilson, Erica G. Kim, Hye Kyong Supardi, Moses Choi, Young Hae Verpoorte, Robert QD Chemistry Iso-α-acids are known to contribute to the characteristic bitter taste of beer. Six iso-α-acids were isolated from a carbon dioxide extract of the cones of Humulus lupulus L. by centrifugal partition chromatography followed by separation through β- cyclodextrin binding. This method overcame the low yield issue of most isolation procedures that results from the low stability of these compounds to light and oxygen. Their full identification was performed using one- and two-dimensional NMR spectrometry, including 1H- and 13C-NMR, 1H-1H COSY, HMQC and HMBC and electrospray ionisation mass spectrometry. The results confirmed the structures of the isolated compounds as trans-isocohumulone, cis-isocohumulone, trans-isohumulone, cis-isohumulone, trans-isoadhumulone and cis-isoadhumulone. Epimers can be easily distinguished by observing the chemical shift differences of the H-5, H-1′″, H-2′″ and C-5 signals and the different splitting pattern of H-5 and H-2″. John Wiley & Sons, Ltd. 2007-08-01 Article PeerReviewed application/pdf en http://irep.iium.edu.my/33742/1/Khatib_et_al%2C_2007._Phytochem._Anal..pdf Khatib, Alfi and Wilson, Erica G. and Kim, Hye Kyong and Supardi, Moses and Choi, Young Hae and Verpoorte, Robert (2007) NMR assignment of iso-α-acids from isomerised extracts of humulus lupulus L. cones. Phytochemical Analysis , 18. pp. 371-377. ISSN 1099-1565 http://onlinelibrary.wiley.com/doi/10.1002/pca.991/abstract 10.1002/pca.991
repository_type	Digital Repository
institution_category	Local University
institution	International Islamic University Malaysia
building	IIUM Repository
collection	Online Access
language	English
topic	QD Chemistry
spellingShingle	QD Chemistry Khatib, Alfi Wilson, Erica G. Kim, Hye Kyong Supardi, Moses Choi, Young Hae Verpoorte, Robert NMR assignment of iso-α-acids from isomerised extracts of humulus lupulus L. cones
description	Iso-α-acids are known to contribute to the characteristic bitter taste of beer. Six iso-α-acids were isolated from a carbon dioxide extract of the cones of Humulus lupulus L. by centrifugal partition chromatography followed by separation through β- cyclodextrin binding. This method overcame the low yield issue of most isolation procedures that results from the low stability of these compounds to light and oxygen. Their full identification was performed using one- and two-dimensional NMR spectrometry, including 1H- and 13C-NMR, 1H-1H COSY, HMQC and HMBC and electrospray ionisation mass spectrometry. The results confirmed the structures of the isolated compounds as trans-isocohumulone, cis-isocohumulone, trans-isohumulone, cis-isohumulone, trans-isoadhumulone and cis-isoadhumulone. Epimers can be easily distinguished by observing the chemical shift differences of the H-5, H-1′″, H-2′″ and C-5 signals and the different splitting pattern of H-5 and H-2″.
format	Article
author	Khatib, Alfi Wilson, Erica G. Kim, Hye Kyong Supardi, Moses Choi, Young Hae Verpoorte, Robert
author_facet	Khatib, Alfi Wilson, Erica G. Kim, Hye Kyong Supardi, Moses Choi, Young Hae Verpoorte, Robert
author_sort	Khatib, Alfi
title	NMR assignment of iso-α-acids from isomerised extracts of humulus lupulus L. cones
title_short	NMR assignment of iso-α-acids from isomerised extracts of humulus lupulus L. cones
title_full	NMR assignment of iso-α-acids from isomerised extracts of humulus lupulus L. cones
title_fullStr	NMR assignment of iso-α-acids from isomerised extracts of humulus lupulus L. cones
title_full_unstemmed	NMR assignment of iso-α-acids from isomerised extracts of humulus lupulus L. cones
title_sort	nmr assignment of iso-α-acids from isomerised extracts of humulus lupulus l. cones
publisher	John Wiley & Sons, Ltd.
publishDate	2007
url	http://irep.iium.edu.my/33742/ http://irep.iium.edu.my/33742/ http://irep.iium.edu.my/33742/ http://irep.iium.edu.my/33742/1/Khatib_et_al%2C_2007._Phytochem._Anal..pdf
first_indexed	2023-09-18T20:48:48Z
last_indexed	2023-09-18T20:48:48Z
_version_	1777409855049433088

NMR assignment of iso-α-acids from isomerised extracts of humulus lupulus L. cones

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