AN ISOPENTENYLATED FLAVONOL FROM HYPERICUM-JAPONICUM .8. PHLOROGLUCINOL DERIVATIVES FROM HYPERICUM-JAPONICUM

Bioactivity guided fractionation of the methanol and ether extracts of the whole plants of Hypericum japonicum has afforded two new phloroglucinol derivatives, sarothralen C and sarothralen D. Their structures were elucidated as 2-{[3,5,7-dihydroxy-8-(2-methyl-1-oxopropyl)-2-methyl-2-(4-methyl-3-pentenyl)-6-chromanyl] meth- yl}-3,5-dihydroxy-6-(2-methyl-1-oxopropyl)-4,4-dimethyl-2,5-cyclohexadien-1-one and 2-{[3,5,7-dihydroxy-6-(2-methyl-1-oxopropyl)-2-methyl-2-(4-methyl-3-pentenyl)-8-chromanyl] methyl}-3,5-dihydroxy-6-(2-methyl-1-oxopropyl) -4,4-dimethyl-2,5-cyclohexadien-1-one respectively, by spectral methods. These compounds possess antimicrobial activity against Staphylococcus aureus.