Bioactivity-Oriented Separation of “Pepper Alkaloids” from Piper sintenense Hatusima with Potential Antigouty Arthritis Activity

Piper sintenense Hatusima (PsH) is a member of the Piper genus used as food and folk medicine in China. However, the detailed chemical ingredients and potential pharmacological effects are still underexploited. In this study, we evaluated the anti-inflammatory and antigouty arthritis effect of the ethanolic extract of P. sintenense. Active compounds were isolated from the petroleum ether fraction resulting in six novel amide alkaloids (1–6) and 13 known analogues (7–19). All of the compounds exhibited excellent anti-inflammatory activities. Bioinformatics analysis and in vitro experiments showed that compound 4 had anti-inflammatory properties (IC₅₀ = 4.86 ± 0.32 μM) and antigouty arthritis activity. Mechanistic studies revealed that compound 4 exerted its favorable efficacy by regulating macrophage polarization by inhibiting P-STAT1/4. These findings provide new insights into the chemical composition and function of P. sintenense and expand its promising application as a functional food in the prevention and treatment of gouty arthritis.