Three new flavonol malonylrhamnosides from Ribes alpinum

Area of Science:

• Phytochemistry
• Natural Products Chemistry
• Organic Chemistry

Background:

• Flavonoids are a diverse group of plant secondary metabolites with various biological activities.
• Malonylated glycosides represent a specific subclass of flavonoids, often exhibiting unique properties.
• Ribes species are known sources of various phytochemicals, but their flavonoid profiles are not fully elucidated.

Purpose of the Study:

• To isolate and characterize novel flavonol malonylrhamnosides from Ribes alpinum leaves.
• To identify other related compounds present in the plant extract.
• To contribute to the phytochemical knowledge of the Ribes genus.

Main Methods:

• Extraction of compounds from Ribes alpinum leaves.
• Isolation and purification using chromatographic techniques.
• Structure elucidation utilizing spectroscopic methods, including 2D Nuclear Magnetic Resonance (2D NMR).

Main Results:

• Three new flavonol malonylrhamnosides were successfully isolated and characterized.
• These compounds are the 3-O-(4"-O-malonyl)-alpha-L-rhamnopyranosides of mearnsetin, myricetin, and quercetin.
• Additionally, mearnsitrin, myricitrin, quercitrin, and 4-O-methyl phloracetophenone 2-O-beta-D-glucopyranoside were identified.

Conclusions:

• The study successfully identified novel compounds in Ribes alpinum, expanding the known diversity of flavonol malonylrhamnosides.
• The characterization provides valuable data for future research on the biological activities and chemotaxonomic significance of these compounds.
• This research enhances the understanding of the phytochemical composition of Ribes species.