New carbamic acid esters, inclusive of salts thereof, which have the formula: ##STR1## wherein n is zero or 1; R.sup.1 and R.sup.2 independently represent --H, --OCH.sub.3 or --OCONHR.sup.6 ; in which R.sup.6 is C.sub.8-26 aliphatic hydrocarbon residue provided that at least one of R.sup.1 and R.sup.2 is --OCONHR.sup.6 ; and R.sup.3, R.sup.4 and R.sup.5 independently represent hydrogen or lower alkyl, or ##STR2## represents cyclic ammonio, exhibit inhibitory activity to multiplication of tumor cells and antimicrobial activity.