Skaar, IreneAdaku, ChristopherJordheim, MonicaByamukama, RobertKiremire, BernardAndersen, Øyvind M.2021-12-142021-12-142014Skaar, I., Adaku, C., Jordheim, M., Byamukama, R., Kiremire, B., & Andersen, Ø. M. (2014). Purple anthocyanin colouration on lower (abaxial) leaf surface of Hemigraphis colorata (Acanthaceae). Phytochemistry, 105, 141-146.http://dx.doi.org/10.1016/j.phytochem.2014.05.016http://dx.doi.org/10.1016/j.phytochem.2014.05.016https://nru.uncst.go.ug/xmlui/handle/123456789/481The functional significance of anthocyanin colouration of lower (abaxial) leaf surfaces is not clear. Two anthocyanins, 5-O-methylcyanidin 3-O-(300-(b-glucuronopyranosyl)-b-glucopyranoside) (1) and 5-O-methylcyanidin 3-O-b-glucopyranoside (2), were isolated from Hemigraphis colorata (Blume) (Acanthaceae) leaves with strong purple abaxial colouration (2.2 and 0.6 mg/g fr. wt., respectively). The glycosyl moiety of 1, the disaccharide 300-(b-glucuronopyranosyl)-b-glucopyranoside), has previously been reported to occur only in a triterpenoid saponin, lindernioside A. The structural assignment of the aglycone of 1 and 2 is the first complete characterisation of a natural 7-hydroxy-5-methoxyanthocyanidin. Compared to nearly all naturally occurring anthocyanidins, the 5-O-methylation of this anthocyanidin limits the type of possible quinoidal forms of 1 and 2 to be those forms with keto-function in only their 7- and 40-positionsenHemigraphis colorataAcanthaceaeAbaxial leaf colourationAnthocyanins5-O-Methylcyanidin3″-O-β-Glucuronopyranosyl-β-glucopyranosideQuinoidal formsArticle