Isolation of Two New Compounds and Other Constituents from Leaves of Piper crocatum and Study of Their Soluble Epoxide Hydrolase Activities

Two new phenolic glucosides, pipercroside A and B (1 and 2), along with 10 known compounds were isolated from the leaves of Piper crocatum Ruiz & Pav. Their chemical structures were elucidated through extensive spectroscopic analyses, including 1D and 2D NMR experiments and HR-ESI-MS analysis and comparison with previously reported data. All the isolated compounds were assessed for soluble epoxide hydrolase (sEH) inhibitory activity. Among them, erigeside II (5) showed inhibitory activity with an IC50 value of 58.5 µM.