Treatment of cutaneous hyperproliferative dermatoses with manoalide

A method of treating psoriasis or acne which method comprises administering to a mammal in need of said treatment an amount therapeutically effective for treating psoriasis and acne of a compound of formula I, either alone or in combination with a pharmaceutically acceptable excipient where formula I is ##STR10## wherein X is --CH.sub.3, --CH.sub.2 OH, --CHO, OR --COOH;

• Y is --H or --OH;
• Z is --H or --OH;
• and
• the dotted line represents either a single bond or a double bond which may be in either the E or Z configuration;
• and
• A is R.sub.m or R.sub.n ##STR11## and when Y is --OH and X is --CHO or --COOH, the compound of formula II includes the hemiacetal or delta-lactose, respectively;
• and
• when X is --COOH, the corresponding alkyl esters, esters derived from alcohols of 1 to 10 carbon atoms;
• and
• when X is --CH.sub.2 OH and/or Y is --OH and/or Z is --OH, the corresponding acyl esters of acids from 1 to 10 carbon atoms;
• and
• the pharmaceutically acceptable salts of those compounds where X or X is --COOH.