Abstract: Cis-epoxide compounds of formula (I-1) and pharmaceutically acceptable salts, hydrates and solvates thereof: ##STR1## wherein: R.sup.1 is a cycloalkyl, or aryl-substituted lower alkyl group;A is a functionalized acyl group of the formula ##STR2## wherein R.sup.2 is a C.sub.1-4 alkyl, or amide-substituted C.sub.1-2 alkyl group;R.sup.3 is a C.sub.1-4 alkoxy, aryloxyalkyl or arylalkoxy, or a nitrogen-containing aromatic radical, or a lower alkoxy group substituted with a nitrogen-containing aromatic radical, or a radical having the formula of ##STR3## wherein R.sup.4 is a hydrogen or a methyl group and R.sup.5 is an alkyl group substituted with a nitrogen-containing aromatic radical; and m is 0 or 1; and B is a functionalized amino group of the formula ##STR4## wherein R.sup.8 and R.sup.9 are independently a C.sub.1-4 alkyl group optionally substituted with an aromatic radical, or an aromatic group.

Abstract: Novel cis-epoxide compounds of formula (I) are useful for treating or preventing diseases caused by HIV infection: ##STR1## wherein A, B, R.sub.1 to R.sub.4 and n have the same meanings as defined in the specification.The novel HIV protease inhibitor of the formula (I) has a specific structure to form a stable bonding with the enzyme active site, which entails a highly enhanced irreversible inhibition against HIV protease.

Abstract: The present invention relates to novel compounds of formula (I) which have inhibitory activity against human immunodeficiency virus ("HIV") protease, a process for the preparation thereof, and compositions for prevention or treatment of AIDS by HIV infection comprising the above compounds as active ingredients. ##STR1## wherein: R.sup.1 is an aromatic group, a nitrogen-containing aromatic group, C.sub.1-4 alkyl group optionally substituted with an aromatic group or a nitrogen-containing aromatic group, C.sub.1-4 alkoxy group optionally substituted with an aromatic group or a nitrogen-containing aromatic group;R.sup.2 is an amino acid residue or a C.sub.1-8 alkyl group substituted with a C.sub.1-4 alkylsulfonyl group;R.sup.3 is a C.sub.1-4 alkyl group optionally substituted with an aromatic group;R.sup.4 is hydrogen or a C.sub.1-4 alkyl group;R.sup.5 is an aromatic group, a C.sub.1-10 alkyl group or a C.sub.1-4 alkyl groups optionally substituted with an aromatic group; andn is 1 or 2.

Abstract: The present invention relates to novel compounds of formula (I) which has inhibitory activities against human immunodeficiency virus ("HIV") protease, a process for the preparation thereof, and compositions for prevention or treatment of AIDS by HIV infection comprising the above compounds as active ingredients. ##STR1## wherein: R.sup.1 is an aromatic group, a nitrogen-containing aromatic group, C.sub.1-4 alkyl group optionally substituted with an aromatic group or a nitrogen-containing aromatic group, C.sub.1-4 alkoxy group optionally substituted with an aromatic group or a nitrogen-containing aromatic group;R.sup.2 is an amino acid residue or a C.sub.1-8 alkyl group substituted with a C.sub.1-4 alkylsulfonyl group;R.sup.3 is a C.sub.1-4 alkyl group optionally substituted with an aromatic group;R.sup.4 is hydrogen or a C.sub.1-2 alkyl group;R.sup.5 is a C.sub.1-10 alkyl group optionally substituted with an aromatic group; andn is 1 or 2.