Arylated Quinoline and Tetrahydroquinolines: Synthesis, Characterization and Their Metabolic Enzyme Inhibitory and Antimicrobial Activities

Abstract

AbstractThe aims of this study are to synthesize and characterize some new phenyl quinoline derivatives and to determine the activities of them and the recently prepared substituted phenyl quinolines against Acetylcholinesterase (AChE) and Charbonic anyhydrase (CA) enzymes and some microorganisms. The 6‐phenyl‐ (3a) and 6,8‐diphenyl‐(4a) tetrahydroquinolines were prepared by treatment of 6‐bromo and 6,8‐dibromo‐1,2,3,4‐tetrahydroquinoline with phenylboronic acids in the presence of Pd catalyze in high yields with respect to our reported procedure. Then, bromination of the 6‐phenyl‐ (3a) and 6,8‐diphenyl‐(4a) tetrahydroquinolines furnished novel 3‐bromo phenyl substituted quinolines14and11and 8‐bromo‐6‐pheyltetrahydroquinoline (13) in excellent yields (91, 99 and 92 %, respectively). Structures of all prepared compounds were characterized by1H NMR,13C NMR, FTIR spectroscopy and elemental analysis. Both novel prepared and recent synthesized phenyl substituted tetrahydroquinolines and quinolines were screened for human carbonic anhydrase I, II isoenzymes (hCAs I and II) and AChE inhibitory and antimicrobial activities. Results indicated that all the synthetic compounds exhibited potent inhibitory activities against all targets as compared to the standard inhibitors, revealed by IC50values. Kivalues of novel substituted (trifluoromethoxy, thiomethyl and methoxy) phenyl quinolines3a–d,4a–c,8–12, and14for hCA I, hCA II and AChE enzymes were obtained in the ranges 0.31–12.44, 0.92‐12.45, and 8.56–27.05 μM, respectively. Moreover, phenyl quinolines3a–b,10,11,14displayed antifungal effect against yeasts in the range of 125–15.62 μg/mL.