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.