Evaluation of the inhibition of angiotensin-converting enzyme by new thiomorpholine compounds using capillary zone electrophoresis

Abstract

The inhibition capacity of the angiotensin converting enzyme (ACE) was determined by 5 different methylthiomorpholine compounds: (4-tert-butyl-2-(thiomorpholin-4-ylmethyl)phenol (LQM318), 4-tert-butyl-2,6-bis(thiomorpholin-4-ylmethyl)phenol (LQM319), 3,5-bis(thiomorpholin-4-ylmethyl) pyrogallol (LQM322), 4-methoxy-2-thiomorpholin-4-ylmethyl-1-phenol (LQM328) and 3,6-bis(thiomorpholin-4-ylmethyl)benzene-1,2-diol (LQM329), using Captopril as a reference. This last drug is used as an antihypertensive agent and known for its biological effect over ACE. The study was done using the capillary electrophoresis technique, with an in-line reaction using hippuryl-histidyl-leucine (HHL) as substrate to produce hippuric acid (HA). HA was detected at 254 nm, which is the detection wavelength to get the quantification of this compound. That was performed under the experimental conditions reported for such interaction. From this, the electrophoretic mobility of hippuric acid was computed in order to deduce the effective migration time and the recovered quantity, to prove and quantify the in-line activity of the enzyme.