Acylated flavonol diglucosides from Lotus polyphyllos

Area of Science:

• Phytochemistry
• Natural Product Chemistry
• Organic Chemistry

Background:

• Lotus polyphyllos is a plant species known to contain various secondary metabolites.
• Flavonoids, a class of natural compounds, are recognized for their diverse biological activities.
• Acylated glycosides represent a subclass of flavonoids with potentially unique properties.

Purpose of the Study:

• To isolate and characterize novel acylated flavonol diglucosides from Lotus polyphyllos.
• To identify and confirm the structures of known flavonoid glucosides present in the plant.
• To contribute to the phytochemical understanding of the Lotus genus.

Main Methods:

• Extraction of bioactive compounds from the whole plant using an aqueous alcohol solvent system.
• Isolation of individual compounds using chromatographic techniques.
• Structure elucidation of the isolated compounds through comprehensive chemical and spectroscopic analyses (e.g., NMR, Mass Spectrometry).

Main Results:

• Three new acylated flavonol diglucosides were successfully isolated: kaempferol 3-O-beta-(6"-O-E-p-coumaroylglucoside)-7-O-beta-glucoside, quercetin 3-O-beta-(6"-O-E-p-coumaroylglucoside)-7-O-beta-glucoside, and isorhamnetin 3-O-beta-(6"-O-E-p-coumaroylglucoside)-7-O-beta-glucoside.
• The known 3,7-di-O-glucosides of kaempferol, quercetin, and isorhamnetin were also identified and characterized.
• The structural assignments were rigorously confirmed by chemical derivatization and detailed spectral data interpretation.

Conclusions:

• The study successfully identified and characterized several acylated flavonol diglucosides and their corresponding non-acylated forms from Lotus polyphyllos.
• The findings expand the known phytochemical profile of Lotus polyphyllos, highlighting the presence of complex flavonoid glycosides.
• This research provides valuable data for further investigations into the biological activities and chemotaxonomic significance of flavonoids in this plant species.