Analgesic alkaloids from .

Objective: To investigate the analgesic substances in the aerial part of (), commonly used for rheumatoid and rheumatism arthritis.

Methods: The analgesic constituents were isolated with the active guidance of hot plate and acetic acid writhing models, and identified by comprehensive spectroscopic analysis.

Results: Thirteen alkaloids (-), two lignans (, ), and three amides (-) were isolated from the active fractions. Among them, compound was a new alkaloid, and compound was a new natural product. The activity evaluation indicated that various pyrrole alkaloids (, , , and ) possessed significant analgesic activities, they could significantly inhibit the mice pain response induced by acetic acid and hot plate at the dosage of 2 mg/kg BW.

Conclusion: The study revealed that the pyrrole alkaloids played important roles in the analgesic activities of .