Two new flavonoids from Selaginella uncinata

Area of Science:

• Phytochemistry
• Natural Product Chemistry
• Organic Chemistry

Background:

• Selaginella uncinata is a plant species known for its diverse secondary metabolites.
• Flavonoids, a class of natural compounds, exhibit various biological activities.
• Apigenin derivatives with C-6 aryl substituents are of interest in natural product research.

Purpose of the Study:

• To isolate and characterize new flavonoid compounds from Selaginella uncinata.
• To elucidate the chemical structures of the isolated compounds.
• To contribute to the understanding of the phytochemical profile of Selaginella species.

Main Methods:

• Isolation of compounds using chromatographic techniques.
• Structure elucidation employing comprehensive spectroscopic analyses, including UV, IR, 1D NMR, 2D NMR, and HR-ESI-MS.
• Identification of known and novel flavonoid derivatives.

Main Results:

• Two new flavonoids, uncinataflavones A (1) and B (2), were successfully isolated.
• A known compound, 6-(5-carboxyl-2-methoxyphenyl)-apigenin (3), was also identified.
• The structures of the new compounds were confirmed through detailed spectroscopic data interpretation.
• All isolated compounds are identified as apigenin derivatives with aryl substituents at the C-6 position.

Conclusions:

• The study successfully identified and characterized two novel apigenin derivatives from Selaginella uncinata.
• The findings expand the known repertoire of flavonoids from the Selaginella genus.
• The comprehensive structural elucidation provides valuable data for further research into the biological activities and chemotaxonomic significance of these compounds.