The present invention provides compounds of formula (I)
 or a pharmaceutically acceptable salt thereof, wherein:
   A is
    X is CH2-CH2-O or -CH2CH2CH2-;
   Q is
    Y is CH2;
   Z is absent;
   B is H;
   D is H,
 and
E is CO2H;
that are useful as antidiabetic agents. Also disclosed are pharmaceutical compositions comprising compounds of formula (I).
                            本发明提供了式 (I) 的化合物
 或其药学上可接受的盐,其中
A 是
 X是
CH2-   -O或-         -;
Q 是
 Y 是    
Z 不存在;
B 是 H;
D 是 H、
 和
E 是 CO2H;
可用作抗糖尿病药物。还公开了包含式(I)化合物的药物组合物。