Please use this identifier to cite or link to this item:
http://hdl.handle.net/20.500.11889/3991
DC Field | Value | Language |
---|---|---|
dc.contributor.author | Fossen, Torgils | |
dc.contributor.author | Rayyan, Saleh | |
dc.contributor.author | Holmberg, Maya H. | |
dc.contributor.author | Nimtz, Manfred | |
dc.contributor.author | Andersen, Øyvind M. | |
dc.date.accessioned | 2017-01-03T06:39:40Z | |
dc.date.available | 2017-01-03T06:39:40Z | |
dc.date.issued | 2007 | |
dc.identifier.uri | http://hdl.handle.net/20.500.11889/3991 | |
dc.description.abstract | The anthocyanin–flavone C-glycoside, (malvidin 3-O-(6IIOa-rhamnopyranosylAIV-b-glucopyranosideAII)-5-O-b-glucopyranoside AIII) (apigenin 6-C-(2II-O-b-glucopyranosylFIII-b-glucopyranosideFII)) malonateAV (AIV-4! AV-1, FIII-6! AV-3) (1), has been isolated from leaves of Oxalis triangularis A. St.-Hil. In the 1D 1H NMR spectrum of 1 dissolved in CD3OD–CF3CO2D (95:5), MTFA, recorded 45 min after sample preparation, this covalently linked dimer occurred mainly as flavylium cation (38%) and two equilibrium forms assigned to be quinonoidal bases (54%), whereas only minor amounts of the hemiacetal forms were present. After five days storage at 300 K, the hemiacetals (39%) and flavylium cation (38%) constituted the main forms of 1. More simple anthocyanins are normally considered to be on the flavylium cation form in acidified deuterated methanol. The cross-peaks observed in NOESY NMR spectra of 1 indicated the presence of vertical ’p–p’ stacking between the B-ring of the flavone unit and the A-ring of each of the two forms assigned to be quinonoidal bases. It was not possible to discriminate between inter- or intramolecular association mechanisms. The equilibria between the various forms of 1 were studied by two-dimensional NOESY and ROESY NMR spectroscopy. 2D HSQC-TOCSY NMR spectroscopy was among the methods used for characterization of the various forms. | en_US |
dc.language.iso | en_US | en_US |
dc.subject | Oxalis triangularis - Identification | en_US |
dc.subject | Oxalis triangularis - Analysis | en_US |
dc.subject | Oxalis triangularis - Spectra | en_US |
dc.subject | Anthocyanins | en_US |
dc.subject.lcsh | Chemical equilibrium | |
dc.subject.lcsh | Leaves | |
dc.subject.lcsh | Botanical chemistry | |
dc.title | Covalent anthocyanin–flavone dimer from leaves of Oxalis triangularis | en_US |
dc.type | Article | en_US |
newfileds.department | Science | en_US |
newfileds.item-access-type | open_access | en_US |
newfileds.thesis-prog | none | en_US |
newfileds.general-subject | none | en_US |
item.grantfulltext | open | - |
item.fulltext | With Fulltext | - |
item.languageiso639-1 | other | - |
Appears in Collections: | Fulltext Publications |
Files in This Item:
File | Description | Size | Format | |
---|---|---|---|---|
Covalent anthocyanin–flavone dimer from leaves of Oxalis triangularis.pdf | 415.04 kB | Adobe PDF | View/Open |
Page view(s)
99
Last Week
0
0
Last month
2
2
checked on Apr 14, 2024
Download(s)
68
checked on Apr 14, 2024
Google ScholarTM
Check
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.