Abstract: The invention concerns adducts of 1,8-dihydroxy-9-anthrone, of formula: ##STR1## in which: R.sub.1 and R.sub.2, taken together, form one of the following divalent residues: ##STR2## R.sub.3, R.sub.4, R'.sub.4, R.sub.5 and R'.sub.5 representing H, an alkyl group having 1-8 C with the exception of R.sub.5 =R'.sub.5 =CH.sub.3, a monohydroxyalkyl group with 2-8 C, possibly interrupted by one or more oxygens, a cycloalkyl group having 4-6 C, a phenyl group, or a benzyl group.Utilization of the compounds (I) in human or veterinary medicine, in particular in the treatment of psoriasis and or warts, and in cosmetics.

Abstract: 1,8-Dihydroxy-9-anthrone derivatives, substituted in the 10-position by an unsaturated radical, are described which have utility as ingredients in human and veterinary pharmaceutical and cosmetic preparations and which are compounds of the structural formula ##STR1## wherein R.sub.1 represents a hydrogen atom or a --CO.sub.2 R'.sub.2 radical,R.sub.2 and R'.sub.2 identical or different, represent a hydrogen atom, a linear or branched chain alkyl radical having 1 to 6 carbon atoms, a cycloalkyl radical having 4 to 6 carbon atoms or a benzyl radical,or R.sub.1 and R.sub.2 taken together form a radical --CO--, and n is 0 or 1,with the proviso that when n is 0 and R.sub.1 is --CO.sub.2 R'.sub.2,R.sub.2 and R'.sub.2 do not simultaneously represent the radical CH.sub.3, and the isomers of the compounds of formula (I) and mixtures thereof.