INS and type 2 diabetes mellitus: Alogliptin (ALO) Fig. 1c, 2-[[6-[(3R)-3-aminopiperidin-1-yl]-3-methyl-2,4-dioxopyrimidin-1- yl]methyl]benzonitrile [7] and vildagliptin (VLD) Fig. 1d, (2 S)-1-[2-[(3-hydroxy-1-adamantyl) amino] acetyl] pyrrolidine-2-carbonitrile [4] are Dipeptidyl Peptidase-4 (DPP-4) inhibitors that are used in the therapy of T2DM via increasing Insulin secretion and suppressing glucagon secretion [8].