5-Pyrrolidinylsulfonyl Isatins as a Potential Tool for the Molecular Imaging of Caspases in Apoptosis
摘要:
Caspases are the unique enzymes responsible for the execution of the cell death program and may represent an exclusive target for the specific molecular imaging of apoptosis in vivo. 5-Pyrrolidinylsulfonyl isatins represent potent nonpeptidyl caspase inhibitors that may be suitable for the development of caspase binding radioligands ( CBRs). ( S)-5-[ 1-(2-Methoxymethylpyrrolidinyl) sulfonyl] isatin ( 7) served as a lead compound for modification of its N-1-position. Corresponding pairs of N-1-substituted 2-methoxymethyl- and 2-phenoxymethylpyrrolidinyl derivatives were examined in vitro by biochemical caspase inhibition assays. All target compounds possess high in vitro caspase inhibtion potencies in the nanomolar to subnanomolar range for caspase-3 ( K-i = 0.2- 56.1 nM). As shown for compound ( S)-1-( 4-(2-fluoroethoxy) benzyl)-5-[ 1( 2-methoxymethylpyrrolidinyl) sulfonyl] isatin ( 35), the class of N-1-substituted 5-pyrrolidinylsulfonyl isatins competitively inhibits caspase-3. All caspase inhibitors show selectivity for the effector caspases-3 and -7 in vitro. The 2-methoxymethylpyrrolidinyl versions of the isatins appear to possess superior caspase inhibition potencies in cellular apoptosis inhibition assays compared with the 2-phenoxymethylpyrrolidinyl inhibitors.
5-Pyrrolidinylsulfonyl Isatins as a Potential Tool for the Molecular Imaging of Caspases in Apoptosis
摘要:
Caspases are the unique enzymes responsible for the execution of the cell death program and may represent an exclusive target for the specific molecular imaging of apoptosis in vivo. 5-Pyrrolidinylsulfonyl isatins represent potent nonpeptidyl caspase inhibitors that may be suitable for the development of caspase binding radioligands ( CBRs). ( S)-5-[ 1-(2-Methoxymethylpyrrolidinyl) sulfonyl] isatin ( 7) served as a lead compound for modification of its N-1-position. Corresponding pairs of N-1-substituted 2-methoxymethyl- and 2-phenoxymethylpyrrolidinyl derivatives were examined in vitro by biochemical caspase inhibition assays. All target compounds possess high in vitro caspase inhibtion potencies in the nanomolar to subnanomolar range for caspase-3 ( K-i = 0.2- 56.1 nM). As shown for compound ( S)-1-( 4-(2-fluoroethoxy) benzyl)-5-[ 1( 2-methoxymethylpyrrolidinyl) sulfonyl] isatin ( 35), the class of N-1-substituted 5-pyrrolidinylsulfonyl isatins competitively inhibits caspase-3. All caspase inhibitors show selectivity for the effector caspases-3 and -7 in vitro. The 2-methoxymethylpyrrolidinyl versions of the isatins appear to possess superior caspase inhibition potencies in cellular apoptosis inhibition assays compared with the 2-phenoxymethylpyrrolidinyl inhibitors.