Studies on Bitter Peptides from Casein Hydrolyzate. XIV. Bitter Taste of Synthetic Analogs of Octapeptide, Arg–Gly–Pro–Phe–Pro–Ile–Ile–Val, Corresponding to the C-Terminal Portion ofβ-Casein
Studies on Bitter Peptides from Casein Hydrolyzate. XIV. Bitter Taste of Synthetic Analogs of Octapeptide, Arg–Gly–Pro–Phe–Pro–Ile–Ile–Val, Corresponding to the C-Terminal Portion ofβ-Casein
Chen, Francis M. F.; Lee, Young; Steinauer, Rene, Canadian Journal of Chemistry, 1987, vol. 65, p. 613 - 618
作者:Chen, Francis M. F.、Lee, Young、Steinauer, Rene、Benoiton, N. Leo
DOI:——
日期:——
Synthesis and biological activity of ketomethylene-containing nonapeptide analogs of snake venom angiotensin converting enzyme inhibitors
作者:Ronald G. Almquist、W. R. Chao、A. K. Judd、C. Mitoma、D. J. Rossi、R. E. Panasevich、R. J. Matthews
DOI:10.1021/jm00398a012
日期:1988.3
Two ketomethylene-containing nonapeptide analogues were synthesized to determine if ketomethylene analogues of the nonapeptide venom inhibitors of angiotensin converting enzyme (ACE) would have oral ACE inhibition activity. Both ketomethylene-containing nonapeptides 18 and 19 were potent inhibitors of rabbit lung ACE with I50s of 3.4 and 8.0 nM, respectively, compared to 340 nM for their parent nonapeptide and 450 nM for captopril. Peptide 18 was rapidly cleaved by trypsin, but 19 was reasonably stable to all enzyme degradation systems tested with maximum degradation of 50% by pepsin in 3 h. Both 18 and 19 when given iv to normotensive rats were between 3 and 10 times more potent than captopril in inhibiting an angiotensin I induced blood pressure increase. Peptide 19 showed no ACE inhibition activity in unanesthetized normotensive rats when administered orally at doses of 10 or 100 mg/kg. Experiments were conducted to determine whether 19 is adsorbed from the gastrointestinal track following oral administration. These experiments indicated that 19 is adsorbed. It is concluded that the lack of oral activity of 19 is probably due to its rapid excretion, probably into the bile.