Comparative Free Radical Scavenging Action of Angiotensin-Converting Enzyme Inhibitors with and without the Sulfhydryl Radical

摘要: The free radical scavenging effects of an angiotensin-converting enzyme (ACE) inhibitor containing sulfhydryl (SH; captopril) were compared with those ACE inhibitors not SH (enalapril, enalaprilat, delapril and its de-esterified products). Electron spin resonance (ESR) using 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) as the trap showed that enalapril (0.6-4.8 mmol/l) inhibited hydroxyl radicals concentration-dependently. Captopril (2.4-10 mmol/ 1), enalaprilat product (1.2–4.8 also in a concentration-dependent manner. captopril (2.4–4.8 on superoxide anion concentration-dependent. Delapril, product, weakly radical. These results indicate both SH- non-SH-containing scavenge more strongly than action is probably related only to presence