is deprotonated form of is enantiomer of 5-(2-{[2-(2-ethoxyphenoxy)ethyl]amino}propyl)-2-methoxybenzenesulfonamide ent-tamsulosin A 5-(2-{[2-(2-ethoxyphenoxy)ethyl]amino}propyl)-2-methoxybenzenesulfonamide that has (<i>S</i>)-configuration. The enantiomer of tamsulosin. ent-tamsulosin(1+) tamsulosin