Isolation and Structural Elucidation of Unreported Prenylhydroquinone Glycoside from Sedum kamtschaticum Leaves and Its Effect on Hyperphosphorylated Tau Production in A beta(1-42)-Treated SH-SY5Y Cells

Sedum kamtschaticum Fischer, of the Crassulaceae family, is a perennial and medicinal plant used in Asian folk medicine to alleviate inflammatory disease and improve blood circulation. As part of our ongoing exploration into natural products, seeking to identifying bioactive compounds, we characterized, identified, and isolated an unreported bioactive compound, prenylhydroquinone glycoside (1), which we named kirinchoside from S. kamtschaticum leaves. Using high-resolution (HR)-ESIMS, NMR spectroscopic data, and enzymatic hydrolysis, followed by LC-MS analysis, we determined the structure of this isolated compound. Despite a previous report on the planar structure of compound 1 (kirinchoside), the absolute configuration of 1 had not been verified. We investigated the effects of kirinchoside on hyperphosphorylated tau (p-tau) accumulation, a hallmark of Alzheimer's disease (AD) progression. We observed that treatment with 5 mu M kirinchoside suppressed p-tau levels by 16.9% in amyloid beta (A beta) 1-42-treated SH-SY5Y cells, compared to the negative control. These findings indicate that kirinchoside, an unreported prenylhydroquinone glycoside found in S. kamtschaticum leaves, could be a candidate preventive agent against AD via inhibition of p-tau accumulation.

Automated summary

In this study, a previously unreported bioactive compound, kirinchoside, was isolated from Sedum kamtschaticum leaves. It was found to have anti-inflammatory and blood circulation-improving effects. It also showed potential as a preventive agent against Alzheimer's disease through the inhibition of hyperphosphorylated tau accumulation.