Costunolide, a Sesquiterpene from the Stem Bark of Magnolia sieboldii, Inhibits the RAS-Farnesyl-Proteintransferase - Park, Sung-Hee; Choi, Sang-Un; Lee, Chong Ock; Yoo, Sung-eun; Yoon, Seok Keun; Kim, Young-Kyoon; Ryu, Shi Yong (Planta Medica, 2001)