Synthesis, β-haematin inhibition, and in vitro antimalarial testing of isocryptolepine analogues: SAR study of indolo[3,2-c]quinolines with various substituents at C2, C6, and N11
作者:Ning Wang、Kathryn J. Wicht、Kento Imai、Ming-qi Wang、Tran Anh Ngoc、Ryo Kiguchi、Marcel Kaiser、Timothy J. Egan、Tsutomu Inokuchi
DOI:10.1016/j.bmc.2014.03.030
日期:2014.5
A series of indolo[3,2-c]quinolines were synthesized by modifying the side chains of the omega-aminoalkylamines at the C6 position and introducing substituents at the C2 position, such as F, Cl, Br, Me, MeO and NO2, and a methyl group at the N11 position for an SAR study. The in vitro antiplasmodial activities of the derivative agents against two different strains (CQS: NF54 and CQR: K1) and the cytotoxic activity against normal L6 cells were evaluated. The test results showed that compounds 6k and 6l containing the branched methyl groups of 3-aminopropylamino at C6 with a Cl atom at C2 exhibited a very low cytotoxicity with IC50 values above 4000 nM, high antimalarial activities with IC50 values of about 11 nM for CQS (NF54), IC50 values of about 17 nM for CQR (K1), and RI resistance indices of 1.6. Furthermore, the compounds were tested for beta-haematic inhibition, and QSAR revealed an interesting linear correlation between the biological activity of CQS (NF54) and three contributing factors, namely solubility, hydrophilic surface area, and beta-haematin inhibition for this series. In vivo testing of 6l showed a reduction in parasitaemia on day 4 with an activity of 38%. (C) 2014 Elsevier Ltd. All rights reserved.