Saxagliptin hydrate945667-22-1100 % similar Saxagliptin361442-04-894 % similar Vildagliptin274901-16-537 % similar (αS)-Α[[(1,1-Dimethylethoxy)carbonyl]amino]-3-hydroxytricyclo[3.3.1.13,7]decane-1-acetic acid361442-00-431 % similar