Thapsigargin is an organic heterotricyclic compound that is a hexa-oxygenated 6,7-guaianolide isolated fron the roots of Thapsia garganica L., Apiaceae. A potent skin irritant, it is used in traditional medicine as a counter-irritant. Thapsigargin inhibits Ca2+-transporting ATPase mediated uptake of calcium ions into sarcoplasmic reticulum and is used in experimentation examining the impacts of increasing cytosolic calcium concentrations. It has a role as a calcium channel blocker and an EC 3.6.3.8 (Ca(2+)-transporting ATPase) inhibitor. It is an organic heterotricyclic compound, a sesquiterpene lactone and a butyrate ester.
