new pharmaceutical compositions extracted from ferula assa - foetida are confirmed to effectively treat influenza a virus . the extraction method of the new pharmaceutical compositions mainly includes steps of : extracting f . assa - foetida with methanol to obtain a crude extract ; fractioning the crude extract with n - hexane - methanol to obtain a methanol extract ; fractioning the methanol extract with chloroform - water to obtain a chloroform extract ; and chromatographing the chloroform extract to obtain the pharmaceutical compositions , which can be further fractioned and chromatographed to obtain various sesquiterpene coumarins .