Antiviral Activity and Constituents of the Nepalese Medicinal Plant Astilbe rivularis

During the screening of Nepalese ethnomedicinal plants for antiviral activities, Astilbe rivularis Buch.-Ham. , Saxifragaceae, was identified as a promising species. Bioassay-guided fractionation led to the isolation of arbutin, bergenin and a bergenin derivative. The structures were established by NMR studies. Except bergenin, the two compounds were found in this plant for the first time. A dimer of bergenin has not been described as a natural product before. The compounds showed in vitro antiviral activity against herpes simplex virus type-1 in non cytotoxic concentrations.