[1] Chem Divers Inc, Small Mol Drug Discovery, San Diego, CA 92121 USA
[2] Russian Acad Sci, Inst Dev Biol, Moscow 119334, Russia
[3] Russian Acad Sci, ND Zelinskii Organ Chem Inst, Moscow 117913, Russia
[4] ImClone Syst, Small Mol Drug Discovery, New York, NY 10014 USA