Hasubanan alkaloids with anti-inflammatory activity from Stephania longa

Area of Science:

• Natural Product Chemistry
• Pharmacology
• Medicinal Chemistry

Background:

• Stephania longa is a plant species known to contain various bioactive alkaloids.
• Hasubanan alkaloids represent a class of natural products with diverse pharmacological properties.
• Inflammation is a complex biological response implicated in numerous diseases.

Purpose of the Study:

• To isolate and characterize new and known hasubanan alkaloids from Stephania longa.
• To evaluate the in vitro anti-inflammatory potential of the isolated compounds.

Main Methods:

• Isolation of alkaloids using chromatographic techniques.
• Structure elucidation employing High-Resolution Electrospray Ionization Mass Spectrometry (HR-ESI-MS), 1D and 2D Nuclear Magnetic Resonance (NMR) spectroscopy, and Electronic Circular Dichroism (ECD) calculations.
• In vitro anti-inflammatory assay measuring the production of Tumor Necrosis Factor-alpha (TNF-α) and Interleukin-6 (IL-6).

Main Results:

• Two new hasubanan alkaloids, stephalonester A (1) and stephalonester B (2), were identified.
• Four known compounds, stephalonine E (3), longanone (4), cephatonine (5), and prostephabyssine (6), were also isolated.
• Compounds 4, 5, and 6 demonstrated significant inhibition of TNF-α and IL-6 production, with IC50 values ranging from 6.54 to 30.44 µM.

Conclusions:

• Stephania longa is a valuable source of hasubanan alkaloids with anti-inflammatory properties.
• Longanone, cephatonine, and prostephabyssine are potent inhibitors of key inflammatory mediators TNF-α and IL-6.
• These findings suggest potential therapeutic applications for these compounds in inflammatory conditions.