An aromatic polycyclic compound has the formula ##STR1## wherein R represents --SO.sub.3 H, SO.sub.2 NHR.sub.3, ##STR2## --SO.sub.2 R.sub.3, --SOR.sub.3 or --SR.sub.3, R.sub.3 represents lower alkyl, monohydroxyalkyl, polyhydroxyalkyl, aminoalkyl, carboxyalkyl, aminocarboxyalkyl or alkoxyalkyl,R' represents hydrogen, lower alkyl, lower alkoxy, hydroxy, C.sub.1 -C.sub.4 acyloxy or amino,R" represents hydrogen, lower alkyl or lower alkoxy, orR' and R", taken together, form an oxo, methano or hydroxyimino radical,R.sub.1 represents hydrogen or lower alkyl,n is 0 or 1,when n=1, R.sub.2 represents hydrogen or lower alkyl, or R.sub.1 and R.sub.2, taken together form a vinylene radical, andAr represents an aromatic radical selected from ##STR3## wherein R.sub.4, R.sub.5, R.sub.6, R.sub.7, R.sub.8, R.sub.9, R.sub.10 and R.sub.11 represent hydrogen or lower alkyl, at least one of R.sub.4 and/or R.sub.5 being other than hydrogen, and at least two of R.sub.8 -R.sub.11 being other than hydrogen,A represents methylene or dimethylene substituted or not by lower alkyl; when A represents dimethylene, R.sub.8 and R.sub.10 together can form a methylene or dimethylene radical,and the salts of the compound of formula I as well as their geometric and optical isomers.These compounds are useful in human and veterinary medicines and in cosmetic compositions.