An antiviral furanoquinone from Paulownia tomentosa Steud

A methanol extract of the stem bark of Paulownia tomentosa showed antiviral activity against poliovirus types 1 and 3. Sequential liquid-liquid extraction with n-hexane, chloroform and water, and a silicagel column chromatography resulted in the purification of a compound. The compound was identified as methyl-5-hydroxy-dinaphthol[1,2-2',3']furan-7,12-dione-6-carbox yla te on the basis of spectroscopic data. The component caused a significant reduction of viral cytopathic effect when it was subjected to a standard antiviral assay by using HeLa cells. The EC(50) of the compound against poliovirus type 1 strain Brunhilde, and type 3 strain Leon were 0.3 microg/mL and 0.6 microg/mL, respectively.