Abstract: An apoptosis inhibitor which comprises a compound of the formula: wherein R represents a hydrocarbon group that may be substituted or a heterocyclic group that may be substituted; Y represents a group of the formula: --CO--, --CH(OH)-- or --NR.sup.3 -- where R.sup.3 represents an alkyl group that may be substituted; m is 0 or 1; n is 0, 1 or 2; X represents CH or N; A represents a chemical bond or a bivalent aliphatic hydrocarbon group having 1 to 7 carbon atoms; Q represents oxygen or sulfur; R.sup.1 represents hydrogen or an alkyl group; ring E may have further 1 to 4 substituents, which may form a ring in combination with R.sup.1 ; L and M respectively represent hydrogen or may be combined with each other to form a chemical bond; or a salt thereof, or a compound having an insulin sensitivity enhancing activity.