A compound of formula (I) or (II): wherein A is hydrogen or CR.sup.1R.sup.2; Y and Z are each, independently, hydrogen or a halogen; X is --NR.sup.4R.sup.5, or R.sup.7; R.sup.1 is hydrogen, or a substituted or unsubstituted alkyl or alkenyl group containing 1 4 carbon atoms; when X is --NR.sup.4R.sup.5, R.sup.2 is a substituted or unsubstituted alkyl, alkenyl, alkynyl, aryl, aralkyl aralkenyl, or aralkynyl group, that optionally includes at least one heteroatom in its carbon skeleton and contains 1 12 carbon atoms; when X is R.sup.7, R.sup.2 is an unsubstituted alkyl, alkenyl or alkynyl group, or a substituted or unsubstituted aryl, aralkyl aralkenyl, or aralkynyl group, that optionally includes at least one heteroatom in its carbon skeleton and contains 1 12 carbon atoms; R.sup.3 is a substituted or unsubstituted alkyl, alkenyl, alkynyl, aryl, aralkyl aralkenyl, or aralkynyl group, that optionally includes at least one heteroatom in its carbon skeleton and contains 1 12 carbon atoms; R.sup.4 is hydrogen, a substituted or unsubstituted alkyl, alkenyl, alkynyl, aryl, aralkyl aralkenyl, or aralkynyl group, that optionally includes at least one heteroatom in its carbon skeleton and contains 1 12 carbon atoms, --COOR.sup.8, or --COR.sup.8; R.sup.5 is hydrogen, or a substituted or unsubstituted alkyl or alkenyl group containing 1 5 carbon atoms; R.sup.7 is an unsubstituted alkyl, alkenyl, or alkynyl group, that contains 1 4 carbon atoms; and, R.sup.8 is an unsubstituted or halo-substituted alkyl, aryl, or aralkyl group, that contains 1 12 carbon atoms ##STR00001##