Abstract: Prostaglandin analogues of the general formula: ##STR1## [wherein the ring A represents: ##STR2## the ring B represents: ##STR3## (wherein R.sup.6 represents hydrogen, methyl or ethyl, and r is zero, one or two), Y represents ethylene, cis- or trans-vinylene or ethynylene, Z represents a grouping of the formula: --(CH.sub.2).sub.m --, --(CH.sub.2).sub.3 --CHR.sup.7 --, --(CH.sub.2).sub.2 --CHR.sup.7 --CH.sub.2 --, --CH.sub.2 --CHR.sup.7 --(CH.sub.2).sub.2 --, --CHR.sup.7 --(CH.sub.2).sub.3 --, or trans--(CH.sub.2).sub.2 --CH.dbd.CH-- (wherein m is 3, 4 or 5, and R.sup.7 represents methyl or ethyl), R.sup.1 represents a grouping of the formula: --COOR.sup.8, ##STR4## or --CH.sub.2 OR.sup.11 (wherein R.sup.8 represents hydrogen, alkyl, aralkyl, cycloalkyl which is unsubstituted or substituted by at least one alkyl group, or R.sup.

Abstract: The imidazole derivatives of the general formula: ##STR1## wherein R.sup.1 represents a hydrogen atom, or a straight- or branched-chain alkyl group containing from 1 to 12 carbon atoms, R.sup.2 represents a hydrogen atom, or a straight- or branched-chain alkyl group containing from 1 to 4 carbon atoms, R.sup.3 represents a straight- or branched-chain alkyl group containing from 1 to 10 carbon atoms, and m and n, which may be the same or different, each represent zero, or an integer of 1 to 10, and non-toxic acid addition salts thereof, and, when R.sup.1 represents a hydrogen atom, non-toxic salts thereof, are new compounds. These compounds have a strong inhibitory effect on thromboxane synthetase from rabbit platelet microsomes, and are useful as therapeutically active agents for inflammation, hypertension, thrombus, cerebral apoplexy and asthma.