Iridoids from Pedicularis verticillata and Their Anti-Complementary Activity

Area of Science:

• Natural Products Chemistry
• Pharmacology

Background:

• The complement system plays a crucial role in innate immunity.
• Iridoids are a class of monoterpenes found in various plants with diverse biological activities.

Purpose of the Study:

• To isolate and characterize new iridoid compounds from Pedicularis verticillata.
• To evaluate the anti-complementary activity of isolated iridoids on the classical pathway.

Main Methods:

• Isolation of compounds using chromatographic techniques.
• Structure elucidation through spectroscopic methods (NMR, MS).
• In vitro anti-complementary activity assay on the classical pathway.

Main Results:

• Three new iridoids, pediverticilatasin A-C (1-3), and five known iridoids (4-8) were isolated.
• Compounds 1, 3, and 6 exhibited anti-complementary activity with CH50 values between 0.43 and 1.72 mM.
• Structure determination confirmed the chemical identities of the novel compounds.

Conclusions:

• Pedicularis verticillata is a source of novel iridoid compounds.
• Compounds 1, 3, and 6 show promise as potential therapeutic agents for complement-mediated disorders.