These LC-MS/MS data were analyzed to determine the content of certain sesquiterpene lactones in Liriodendron tulipifera and several Magnolia species. These files are associated with the journal article - Screening the PRISM library against Staphylococcus aureus reveals a sesquiterpene lactone from Liriodendron tulipifera with inhibitory activity. Methods can be found in the journal article.