(untitled) - Jang,M.; Cai,L.; Udeani,G.O.; Slowing,K.V.; Thomas,C.F.; Beecher,C.W.W.; Fong,H.H.S.; Farnworth,R.N.; Kinghorn,A.D.; Metha,R.G.; Moon,R.C.; Pezzuto,J.M. (Science, 1997)