Considering the family of Acetylcysteine mucolytic agent ("spiders" at the bottom of Figure and on the right of Figure ), there are obvious, also mucolytic progenies (Mesna, Mecysteine and Carbocysteine) as well as three interesting progenies with different but, we think, promising indications: Bucillamine used in rheumatoid arthritis , Penicilamine used against Wilson's desease , and Tromethamine antiasthmatic . All of these progenies show significant conformational overlap with the Acetylcysteine parent (see examples in Figures ). Several of them contain a reactive thiol group, which may break disulfide bonds in some proteins or act by influencing the oxidative-reductive balance in the organism (in many cases, the actual mechanism remains unknown) . Compounds of similar properties (but containing disulfide bridges rather than free SH groups) were shown to have potential therapeutic effect on COVID-19 .