Oleanane-type triterpenoids from Sabia limoniacea with nitric oxide inhibitory activity

Area of Science:

• Natural Product Chemistry
• Organic Chemistry
• Pharmacology

Background:

• Sabia limoniacea is a plant source of bioactive compounds.
• Triterpenoids are a diverse class of natural products with various biological activities.

Purpose of the Study:

• To isolate and characterize novel oleanane-type triterpenoids from Sabia limoniacea.
• To evaluate 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 extensive spectroscopic analyses (1D and 2D NMR, HRESIMS).
• Biological evaluation using lipopolysaccharide-stimulated RAW264.7 cells to assess nitric oxide inhibition.

Main Results:

• Fourteen undescribed oleanane-type triterpenoids (Sabialimons S-Z6), including five nortriterpenoids and nine normal triterpenoids, were identified.
• Compounds 1-3 exhibited a contracted ring-A nortriterpenoid structure (5/6/6/6/6 pentacyclic skeleton).
• Compounds 4 and 5 displayed a ring-A-seco tetracyclic skeleton (0/6/6/6/6 tetracyclic skeleton).
• Compounds 9 and 10 inhibited nitric oxide production with IC50 values of 36.40 μM and 36.52 μM, respectively.

Conclusions:

• The study successfully identified novel triterpenoids from Sabia limoniacea with unique structural features.
• Compounds 9 and 10 show potential as anti-inflammatory agents due to their nitric oxide inhibitory activity.