Compounds having the following structure (I):
or a stereoisomer, tautomer, pharmaceutically acceptable salt or prodrug thereof, wherein R
1
, R
2
, R
3
, R
4
, R
8
, R
9
, R
10
, R
11
, R
12
, A
1
, A
2
, X, Y and Z are as defined herein. Uses of such compounds as TGR5 antagonists and for treatment of various indications, including Type II diabetes meletus are also provided.