Abstract: A phosphinic acid derivative represented by the general formula [I], or a pharmaceutically acceptable salt thereof, ##STR1## wherein R.sup.1 represents an alkyl, cycloalkyl or aralkyl group which may be substituted; R.sup.2 and R.sup.5 may be identical or different, and each represents a hydrogen atom, or an ester residue capable of forming a non-toxic ester hydrolyzable in vivo; and A represents a group of the formula ##STR2## wherein R.sup.3 represents an alkyl group, a group of the formula ##STR3## wherein R.sup.30 represents a halogen atom, a carboxyl group, a hydroxyl group, a cycloalkyl group which may be substituted, an aryl group which may be substituted, an arylthio group, a heteroarylthio group which may be substituted, an alkylthio group which may be substituted, an amino group which may be substituted, or a lower alkoxycarbonyl group; R.sup.

Abstract: A 1,3-dithiole derivative having the formula: ##STR1## wherein each of R.sup.1 and R.sup.2 is a substituted or unsubstituted alkyl, cycloalkyl, lower alkenyl, lower alkynyl, aryl or aralkyl group or R.sup.1 and R.sup.2 together form a substituted or unsubstituted alkylene or alkenylene group having from 3 to 6 carbon atoms, which may contain a cycloalkylene group, an o-phenylene group or a hetero atom selected from the group consisting of an oxygen atom, a sulfur atom and a nitrogen atom which may have a substituent, and Q is an acid residue useful for the treatment of liver diseases.

Abstract: A 1,3-dithiol-2-ylidene derivative of the formula: ##STR1## wherein each of R and R.sup.1 which may be the same or different, is a lower alkyl group, a lower alkenyl group, a cycloalkyl group, a lower alkoxyalkyl group, or a substituted or unsubstituted aryl, aralkyl or heterocyclic group, or R and R.sup.1 together form a substituted or unsubstituted ethylene or trimethylene group.