Costunolide, a sesquiterpene from the stem bark of Magnolia sieboldii, inhibits the Ras-farnesyl-protein transferase - Park,S.H.; Choi,S.U.; Lee,C.O.; Yoo,S.; Yoon,S.K.; Kim,Y.K.; Ryu,S.Y. (Planta Medica, 2001)