Novel carboxylic acid derivatives of general formula (I), salts of the same,
esters thereof, or hydrates of them, which are useful as insulin resistance improvers;
and drugs containing the derivatives as the active ingredient. In said formula,
R1 is hydrogen, hydroxyl, alkyl, or the like; L is a single bond, a
double bond, alkylene, or the like; M is a single bond, alkylene, or the like;
T is a single bond, alkylene, or the like; W is carboxyl, CON(RW1)RW2,
or the like; represents a single or double bond; X is oxygen, alkenylene, or the
like; Y is an aromatic hydrocarbon group which may contain a heteroatom, or the
like; and Z is an aromatic hydrocarbon group which may contain a heteroatom.
##STR1##
