Megastigmane glycosides from Urena lobata

Area of Science:

• Natural Product Chemistry
• Medicinal Chemistry
• Pharmacology

Background:

• Urena lobata is a traditional medicinal plant.
• Megastigmane glycosides are a class of natural compounds with diverse biological activities.

Purpose of the Study:

• To isolate and characterize new megastigmane glycosides from Urena lobata.
• To investigate the biological activity of the isolated compounds, specifically their effect on nitric oxide production.

Main Methods:

• Isolation of compounds using chromatographic techniques.
• Structure elucidation using spectroscopic methods (NMR, IR, HRESIMS).
• Calculation of electronic circular dichroism for structural confirmation.
• In vitro assay for nitric oxide inhibition in LPS-stimulated RAW264.7 macrophage cells.

Main Results:

• Five new megastigmane glycosides, urenalobasides A-E (1-5), were identified.
• Eleven known megastigmane glycosides (6-16) were also isolated.
• Compounds 1 and 2 possess a unique 6/5 fused ring system.
• Compound 3 demonstrated significant inhibition of nitric oxide production (IC50 = 53.7 μM).

Conclusions:

• The study successfully identified novel megastigmane glycosides from Urena lobata.
• Urenalobaside A-E represent new chemical entities with potential therapeutic applications.
• Compound 3 exhibits anti-inflammatory potential by inhibiting nitric oxide production, warranting further investigation.