Isoprene derivatives

摘要

Isoprene derivatives of formula (I) (I) wherein m is an integer of 0 to 3, n is an integer of 5 to 12, A is cyclo(C3-C6)alkylene, phenylene, fluorenylene, pyrrolidinylene, piperazinylene, 9-aza-3-oxabicyclo[3.3.1]-nonylene, R1 and R2 are each independently benzyl, of which a phenyl ring may be substituted by 1 to 5 substituents selected from the group consisting of hydroxy, (C1-C4)alkyl, (C1-C4)alkoxy and halogen, X is a single bond or a divalent radical of -(CH2)pNH-, p is an integer of 0 to 3, or a pharmaceutically acceptable salt thereof. Those compounds are useful as multidrug resistance inhibitors for overcoming multidrug resistance of cancer and agents for enhancing an activity of anti-cancer agents./!