Exploration of Orally Available Calpain Inhibitors 2: Peptidyl Hemiacetal Derivatives
摘要:
We previously reported a potent calpain inhibitor 1 ( SJA6017, N-( 4-fluorophenyl)-L-valyl-L-leucinal), which displayed relatively low oral bioavailability ( BA). Replacing the metabolically labile aldehyde moiety of 1 with more chemically stable warheads, such as a cyclic hemiacetal, hydrazone, and alpha-ketoamide, provided the inhibitors with improved in vitro metabolic stability. Cyclic hemiacetal 2 was the most stable of these compounds. The optimization of 2 led to hemiacetal 8 ( SNJ-1715) which exhibited high potency, good aqueous solubility, excellent oral BA, and prolonged plasma half-life in rats. Furthermore, 8 showed neuroprotective efficacy via oral administration in a rat retinal ischemia model.
Exploration of Orally Available Calpain Inhibitors 2: Peptidyl Hemiacetal Derivatives
摘要:
We previously reported a potent calpain inhibitor 1 ( SJA6017, N-( 4-fluorophenyl)-L-valyl-L-leucinal), which displayed relatively low oral bioavailability ( BA). Replacing the metabolically labile aldehyde moiety of 1 with more chemically stable warheads, such as a cyclic hemiacetal, hydrazone, and alpha-ketoamide, provided the inhibitors with improved in vitro metabolic stability. Cyclic hemiacetal 2 was the most stable of these compounds. The optimization of 2 led to hemiacetal 8 ( SNJ-1715) which exhibited high potency, good aqueous solubility, excellent oral BA, and prolonged plasma half-life in rats. Furthermore, 8 showed neuroprotective efficacy via oral administration in a rat retinal ischemia model.
Pseudopeptide Inhibitors of Ras Farnesyl-Protein Transferase
作者:Samuel L. Graham、S. Jane deSolms、Elizabeth A. Giuliani、Nancy E. Kohl、Scott D. Mosser、Allen I. Oliff、David L. Pompliano、Elaine Rands、Michael J. Breslin
DOI:10.1021/jm00032a004
日期:1994.3
Inhibitors of Ras farnesyl-protein transferase are described. These are reduced pseudopeptides related to the C-terminal tetrapeptide of the Ras protein that signals farnesylation. Deletion of the carbonyl groups between the first two residues of the tetrapeptides either preserves or improves activity, depending on the peptide sequence. The most potent in vitro enzyme inhibitor described (IC50 = 5 nM) is Cys[PSICH2NH]Ile[PSICH2NH]Phe-Met(3). To obtain compounds able to suppress Ras farnesylation in cell culture, further structural modification to include a homoserine lactone prodrug was required. Compound 18(Cys[PSICH2NH]Ile[PSICH2NH]Ile-homoserine lactone)reduced the extent of Ras farnesylation by 50 % in NIH3T3 fibroblasts in culture at a concentration of 50 muM. Structure-activity studies also led to 12 (Cys[PSICH2NH]Val-Ile-Leu), a potent and selective inhibitor of a related enzyme, the type-I geranylgeranyl protein transferase.