Acetylcholinesterase inhibition by two phosphoric 4-nitroanilides

Two phosphoric 4-nitroanilides Z2P(O)NH-phi-NO2 (A, Z = Me; B, Z = NMe2) have been prepared and purified by chromatographic techniques. Their spectral data (uv, ir and 1H-nmr) have been determined, and compared with those of other similar compounds. Their ability to inhibit acetylcholinesterase has been measured by a modification of Ellman's method. The data, as computed according to the Michaelis scheme, indicate that A is not an inhibitor, whereas B is a reversible mixed one. These differences are discussed in terms of hydrophobic interactions.