Three New Abietane-Type Diterpenoids from Callicarpa macrophylla Vahl

Area of Science:

• Natural Product Chemistry
• Pharmacology
• Immunology

Background:

• Callicarpa macrophylla Vahl is a plant source of bioactive compounds.
• Abietane-type diterpenoids are a class of natural products with diverse biological activities.
• Nitric oxide (NO) production in macrophages is a key mediator of inflammation.

Purpose of the Study:

• To isolate and characterize new abietane-type diterpenoids from Callicarpa macrophylla Vahl.
• To evaluate the inhibitory activity of the isolated compounds on nitric oxide production in lipopolysaccharide (LPS)-activated RAW 264.7 macrophage cells.

Main Methods:

• Isolation of compounds using chromatographic techniques.
• Structure elucidation using spectroscopic methods including IR, UV, MS, and 1D/2D NMR.
• Assessment of NO inhibitory activity using MTT assays in LPS-activated RAW 264.7 macrophages.

Main Results:

• Three new abietane-type diterpenoids, callicapoic acid M3 (1), callicapoic acid M4 (2), and callicapoic acid M5 (3), were successfully isolated.
• The structures of compounds 1, 2, and 3 were confirmed through comprehensive spectroscopic analysis.
• Compounds 1, 2, and 3 exhibited potent inhibitory activity against NO production, with inhibition rates ranging from 34.47% to 40.13%.

Conclusions:

• The study successfully identified three novel abietane-type diterpenoids from Callicarpa macrophylla Vahl.
• The isolated compounds possess significant potential as inhibitors of nitric oxide production.
• These findings suggest that callicapoic acids M3-M5 may serve as lead compounds for developing anti-inflammatory agents.