3'-Caffeoylquercetin Glycosides and 4'-Caffeoylkaempferol Glycosides-Novel Antioxidant Flavonoids Discovered in the Freesia Yellow Flowers.

ABSTRACT: The petals of flowering plants should retain unique antioxidants that have not been found in the fruits, as the petals need to stay open to attract pollinators against photooxidation and devise a solution to avoid eating attacks. We reported that the yellow petals of freesia cultivars (Freesia x hybrida) accumulated original apocarotenoids, mono- and di-neapolitanosyl crocetin. Here, in the yellow petals, we discovered eight novel flavonoids by their structural determination, including four 3'-caffeoylquercetin 3,7-glycosides, one 3'-caffeoylquercetin 3-glycoside, and three 4'-caffeoylkaempferol 3,7-glycosides. The 3-carbon sugar part was a minor hexose dimer [D-glucosyl-D-glucoside or D-glucosyl-L-rhamnoside] with the β1,2-linkage, while the 7-carbon was usually O-glycosylat

SUBMITTER: Shindo K 

PROVIDER: S-EPMC11851390 | biostudies-literature | 2025 Jan

REPOSITORIES: biostudies-literature