Jatrophane diterpenes as P-glycoprotein inhibitors. First insights of structure-activity relationship and discovery of a new powerful lead - Corea,G.; Fattorusso,E.; Lanzotti,V.; Tagliatatela-Scafati,O.; Appendino,G.; Ballero,M.; Simon,P.-N.; Dumontet,C.; Di Pietro,A. (J Med Chem, 2003)