Alkaloid constituents from Anacyclus pyrethrum.

Area of Science:

• Natural Product Chemistry
• Pharmacognosy
• Medicinal Chemistry

Background:

• Anacyclus pyrethrum (L.) DC. is a plant with a history of traditional medicinal use.
• The isolation and characterization of novel bioactive compounds from medicinal plants remain a key area of research.

Purpose of the Study:

• To isolate and elucidate the structures of new alkaloids from the root of Anacyclus pyrethrum.
• To evaluate the biological activity of the isolated compounds, specifically their effect on nitric oxide production.

Main Methods:

• Isolation of alkaloids using chromatographic techniques.
• Structure elucidation through comprehensive spectroscopic analyses (UV, IR, NMR) and HRESIMS.
• Confirmation of structures using quantum chemical calculations (ECD, NMR) and single-crystal X-ray diffraction.

Main Results:

• Twelve previously undescribed alkaloids were isolated: eight pyrrolo[3,2-g]isoquinoline alkaloids (1-6) and four pyrrolo[2,3-g]quinoline alkaloids (7-9).
• The structures of all isolated compounds were definitively determined.
• Compounds (+)/(-)-anacyquinoline G (7a/7b) and (±)-anacyquinoline H (8) exhibited inhibitory activity against nitric oxide production with IC50 values of 41.4, 44.1, and 31.4 μM, respectively.

Conclusions:

• The study successfully identified novel alkaloid structures from Anacyclus pyrethrum.
• Specific pyrroloquinoline alkaloids demonstrate potential anti-inflammatory properties through the inhibition of nitric oxide production.
• These findings contribute to the understanding of the phytochemical constituents of Anacyclus pyrethrum and their potential therapeutic applications.