Abstract
Tarconanthus camphoratus is a perennial traditional medicinal herb and is a rich source of sesquiterpene lactones called parthenolides. 4xi-Germacra-1(10)-11(13)-dien-12-oic-acid-4,5-epoxy-6 alpha -hydroxy-gamma-lactone(parthenolide) contains both an alpha-methylene-gamma-lactone ring and an epoxide group, which interact with the nucleophilic sites of many biological molecules. Here in, we reported the crystal structure in vitro antimicrobial activities and MIC evaluation of parthenolide isolated from Saudi Arabian plant.