Selaginellin Derivatives from Selaginella tamariscina and Their Upregulating Effects on Low-Density Lipoprotein Receptor Expression.

Two new dimeric selaginellins, diselaginellins C and D (1 and 2), a new unusual derivative, selapiginellin A (4), a new selaginpulvilin U (5), and a known derivative, diselaginellin A (3), were isolated from Selaginella tamariscina (P. Beauv.) Spring. Among these compounds, selapiginellin A (4) is the first naturally occurring compound comprising an ether-linked dimer of a selaginellin and a selaginpulvilin. The absolute configurations of 1, 2, and 4 were elucidated by spectroscopic data analyses. Compound 5 was found to regulate mRNA expression of the low-density lipoprotein receptor (LDLR) gene and LDLR-related genes.