|Clark, Benjamin - University Of Hawaii|
|Borris, Robert - University Of Hawaii|
Submitted to: Natural Product Communications
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/18/2012
Publication Date: 6/15/2012
Citation: Clark, B.R., Suzuki, J.Y., Bliss, B.J., Borris, R.P. 2012. Flavone C-glycosides from Anthurium andraeanum. Natural Product Communications. 7(6):747-748. Interpretive Summary: Cultivated varieties of Anthurium andraeanum represent an important horticultural, cut flower crop, valued for their attractive spathes, leaf-like organs that are brightly colored due to pigments called anthocyanins. Although anthocyanins, members of a group of compounds known as flavonoids have been studied in spathes, little is known about the other flavonoids in leaves or spathes of Anthurium. In this study we applied the latest analytical methods for compound separation and molecular structure determination to identify anthocyanin-related metabolites found in Anthurium tissue. Three flavonoid compounds were identified in leaves of Anthurium andraeanum. Two of the three flavonoids are types of flavones that have not been described previously in the literature from any organism. The results from this research demonstrates the utility of applying modern analytical methods for identification of anthocyanin-related flavonoids in Anthurium and represents to our knowledge the first report of the molecular structure of non-anthocyanin flavonoids in Anthurium andraeanum. The methodologies presented here will support further research towards understanding the synthesis of anthocyanin from flavonoid precursors in Anthurium and development of cultivars with novel colors through anthocyanin pathway manipulation.
Technical Abstract: Anthurium andraeanum is a popular ornamental plant that produces modified leaf structures known as spathes that are brightly colored due to accumulation of anthocyanins. While anthocyanin pigments of the Anthurium genus have been investigated, their other flavonoid constituents have received little attention, with a single known report on the isolation of C-glycosides from A. versicolor. In the work presented here, three flavone 6-C-glycosides were fractionated from crude methanol-HCl extracts from leaves of A. andraeanum using reversed-phase HPLC. One was identified as a known flavone glycoside, embinin. The other two compounds were identified through spectroscopic analysis and chemical transformation and are newly described flavone glycosides, 4’’’-(3,4-dimethoxycinnamoyl)-embinin and 4’’’-ferruloyl-embinin. While 6-C-flavonoid glycosides decorated with ferruloyl and cinnamoyl moieties are not uncommon, in most instances the substitution occurs at the 2 and 6 positions of both C-and O-linked sugars. The particular substitution pattern identified, with attachment at the 4’’’-position of flavone 6-C-glycosides, has not previously been described and is reported here for the first time. To our knowledge this is also the first report of the molecular structure of non-anthocyanin flavonoids from Anthurium andraeanum.