"Ikuma Y, Hochigai H, Kimura H, Nunami N, Kobayashi T, Uchiyama K, Umezome T, Sakurai Y, Sawada N, Tadano J, Sugaru E, Ono M, Hirose Y, Nakahira H.: Discovery of 3H-imidazo[4,5-c]quinolin-4(5H)-ones as potent and selective dipeptidyl peptidase IV (DPP-4) inhibitors: use of a carboxylate prodrug to improve bioavailability. Bioorg Med Chem, Volume 23 (4), 2015"^^; "10.1016/j.bmc.2014.12.051"^^; "25596166"^^; .