Anti-Inflammatory Oleanolic Triterpenes from Chinese Acorns

Area of Science:

• Phytochemistry
• Pharmacology
• Natural Products Chemistry

Background:

• Acorns (Quercus serrata var. brevipetiolata) are historically significant and globally consumed.
• Triterpenes are a class of natural compounds with diverse biological activities.

Purpose of the Study:

• To isolate and characterize oleanolic triterpenes from Chinese acorns.
• To evaluate the anti-inflammatory potential of isolated triterpenes.

Main Methods:

• Isolation of eleven oleanolic triterpenes using chromatographic techniques.
• Structural elucidation of compounds via spectroscopic methods (IR, HR-ESI-MS, NMR).
• In vitro anti-inflammatory assays measuring nitric oxide (NO) inhibition in RAW 264.7 macrophages and cytokine inhibition in MH7A cells.

Main Results:

• A novel oleanolic triterpene, 2α,3β,19α-trihydroxy-24-oxo-olean-12-en-28-oic acid (1), was identified.
• Compounds 1, 3, 6, and 8 displayed potent inhibition of NO production (IC50 values 5.4–8.9 μM).
• Compound 1 also inhibited tumor necrosis factor-alpha (TNF-α)-induced interleukin-6 (IL-6) and interleukin-8 (IL-8) production.

Conclusions:

• Chinese acorns are a rich source of bioactive oleanolic triterpenes.
• Several isolated triterpenes possess significant anti-inflammatory properties.
• The novel triterpene (1) and other isolates show promise for developing anti-inflammatory agents.