Three acylated flavone glycosides from Sideritis syriaca

Area of Science:

• Phytochemistry
• Natural Product Chemistry
• Organic Chemistry

Background:

• Sideritis species are known for their diverse phytochemical profiles.
• Flavonoids and their glycosides are common secondary metabolites in medicinal plants.
• Understanding the chemical constituents of Sideritis syriaca is important for its ethnobotanical and pharmacological applications.

Purpose of the Study:

• To isolate and characterize novel and known compounds from the aerial parts of Sideritis syriaca.
• To identify new flavone glycosides and report previously unknown compounds within the Sideritis genus.

Main Methods:

• Extraction of compounds from the aerial parts of Sideritis syriaca.
• Structure elucidation using Nuclear Magnetic Resonance (1H NMR, 13C NMR) spectroscopy.
• Mass Spectrometry (MS) and chemical methods for compound characterization.

Main Results:

• A new flavone glycoside, 5,8,3 -trihydroxy-4 -methoxyflavone 7-(6 -O-acetylsophoroside), was identified.
• Apigenin 7-(6"-p-coumaroylglucoside) and apigenin 7-(4"-p-coumaroylglucoside) were isolated and reported for the first time in the Sideritis genus.
• The structures of the isolated compounds were confirmed through comprehensive spectroscopic and chemical analyses.

Conclusions:

• The phytochemical investigation of Sideritis syriaca led to the discovery of a new flavone glycoside.
• This study expands the known chemical diversity of the Sideritis genus by reporting new compounds.
• The identified compounds contribute to the understanding of the chemical constituents of Sideritis species.