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dc.contributor.authorSkaar, Irene
dc.contributor.authorJordheim, Monica
dc.contributor.authorByamukama, Robert
dc.contributor.authorMbabazi, Angella
dc.contributor.authorWubshet, Sileshi G.
dc.contributor.authorKiremire, Bernard
dc.contributor.authorAndersen, Øyvind M.
dc.date.accessioned2021-12-14T11:03:51Z
dc.date.available2021-12-14T11:03:51Z
dc.date.issued2012
dc.identifier.other10.1021/jf2048004
dc.identifier.urihttps://nru.uncst.go.ug/xmlui/handle/123456789/483
dc.description.abstractPhytochemical investigations of blue plumbago (Plumbago auriculata Poir. syn. Plumbago capensis Thunb.) flowers have led to the isolation of six new anthocyanins based on three new anthocyanidins with 5,7-dimethoxylated A-rings. Their structures were identified by 2D nuclear magnetic resonance and high-resolution mass spectrometry as the 3-O-β- galactopyranosides (1,2,4) and 3-O-α-rhamnopyranosides (3,5,6) of 5,7-dimethyldelphinidin, 5,7-dimethylpetunidin, and 5,7- dimethylmalvidin. Identification of 1−6 implies new structures for the previously reported anthocyanidins pulchellidin, europinidin, and capensinidin to be 5,7-dimethoxy-3,3′,4′,5′-tetrahydroxyflavylium, 5,7,3′-trimethoxy-3,4′,5′-trihydroxyflavylium, and 5,7,3′,5′-tetramethoxy-3,4′-dihydroxyflavylium cations, respectively. The anthocyanins (0.4 mg/g flowers) were accompanied by the dihydroflavonol taxifolin 3′-O-β-glucopyranoside (1.4 mg/g) and the flavonols 5-methylquercetin 3-O-α-rhamnopyranoside (8.8 mg/g) and 5-methylquercetin (0.4 mg/g). The anthocyanins 1−6 are the first reported natural anthocyanins with no free hydroxyl groups in their 5- and 7-positions on their A-rings. They have thus no possibility of forming the tautomeric quinonoidal bases (anhydrobases), which are related to the free hydroxyl groups in the 5- and 7-positions of previously reported anthocyanins. The genes behind the 5,7-dimethoxylated anthocyanins might be useful for making anthocyanins with special properties (colors, etc.).en_US
dc.language.isoenen_US
dc.publisherJournal of agricultural and food chemistryen_US
dc.subjectPlumbago auriculata synen_US
dc.subjectCapensisen_US
dc.subject7-dimethoxylated anthocyanidin A-ringsen_US
dc.subjectCapensinidinen_US
dc.subjectEuropinidinen_US
dc.subjectPulchellidinen_US
dc.titleNew Anthocyanidin and Anthocyanin Pigments from Blue Plumbagoen_US
dc.typeArticleen_US


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