Provided herein are compounds of the formula (I): as well as pharmaceutically acceptable salts thereof, wherein the substituents are as those disclosed in the specification. These compounds, and the pharmaceutical compositions containing them, are useful for the treatment of diseases such as, for example, type II diabetes mellitus and metabolic syndrome.本發明提供式(I)化合物：；(I)；以及其醫藥學上可接受之鹽，其中該等取代基為如本說明書中所揭示之彼等取代基。該等化合物及含其之醫藥組合物適用於治療疾病，諸如II型糖尿病及代謝型症候群。
