Captopril (SQ 14225) hydrochloride is an antihypertensive agent that is a thiol-containing competitive, orally active angiotensin-converting enzyme (ACE) inhibitor with IC 50 of 0.025 μM and has been widely used for research of hypertension and congestive heart failure. Captopril hydrochloride is also a New Delhi metallo-β-lactamase-1 (NDM-1) inhibitor with an IC 50 of 7.9 μM [1] [2] [3].

Captopril (SQ 14225) hydrochloride has been shown to have similar morbidity and mortality benefits to those of diuretics and beta-blockers in hypertensive patients. Captopril hydrochloride has been shown to delay the diabetic nephropathy progression, while enalapril and lisinopril prevent the development of nephropathy in normoalbuminuric patients with diabetes [4]. An equimolar ratio of the cis and trans states of Captopril hydrochloride exists in solution and that the enzyme selects only the trans state of the inhibitor that presents architectural and stereoelectronic complementarity with its substrate binding groove [5].