Design, synthesis, and biological evaluation of novel quinoline derivatives as small molecule mutant EGFR inhibitors targeting resistance in NSCLC: In vitro screening and ADME predictions.

Here in, we report the design, synthesis and in vitro anticancer activity of a novel series of 24 quinoline analogues of substituted amide and sulphonamide derivatives. The anticancer activity of the synthesised compounds was evaluated against the HCC827, H1975 (L858R/T790 M), A549 (WT EGFR), A-549 and BEAS-2B cell lines. The majority of quinoline compounds demonstrated a significant cytotoxic effect. Compound 21 was found to be the most potent, with IC50 values of 0.010 µM, 0.21 µM, 0.99 µM and 2.99 µM as compared to Osimertinib with IC50 values with of 0.0042 µM, 0.04 µM, 0.92 µM and 2.67 µM. Compound 21 exhibited promising inhibitory enzymatic activity against the EGFR L858R/T790 M with IC50 value of 138 nM, comparable to Osimertinib's 110 nM. Employing a Western blot assay on the phosphorylation of EGFR and the signalling pathways transmission in HCC827 cells, the anticancer activity of the synthesised compounds 18 and 21 was evaluated in terms of its mechanism of action. All the compounds were subjected to a comparative molecular docking study against various EGFR enzyme types, including the wild-type (PDB: 4I23) and T790 M mutant (PDB: 2JIV) enzymes. Furthermore, compounds were examined at the allosteric binding site of the EGFR enzyme with the L858R/T790 M/C797S mutation (PDB ID: 5D41). The MD simulation study was also performed for EGFR-compound 21 complex which indicates the stability compound 21 in both ATP and allosteric site of enzyme. Further, in silico ADME prediction studies of all derivatives were found promising, signifying the drug like properties.

Design and synthesis of novel conformationally constrained 7,12-dihydrodibenzo[b,h][1,6] naphthyridine and 7H-Chromeno[3,2-c] quinoline derivatives as topoisomerase I inhibitors: In vitro screening, molecular docking and ADME predictions.

Novel non-camptothecin (non-CPT) class of conformationally constrained, hitherto unknown 7,12-dihydrodibenzo[b,h][1,6] naphthyridine and 7H-Chromeno[3,2-c] quinoline derivatives have been designed, synthesized and evaluated for anti-cancer activity. In vitro anti-proliferation evaluation against human cancer cell lines (A549 and MCF-7) exhibited significant cytotoxicity. Among the derivatives (8-24), 8 (IC50 0.44 µM and IC50 0.62 µM) and 12 (IC50 0.69 µM and IC50 0.54 µM) were identified as the most promising candidate against A-549 and MCF-7 cancer cell lines respectively. Topo I inhibitory activity of 8 and 12 suggested that, they may be developed as potential anti-cancer molecules in future and rationalized by docking analysis with effective binding modes. Further, in silico ADME prediction studies of all derivatives were found promising, signifying the drug like properties. In precise, the present investigation displays a new strategy to synthesize and emphasis on anticancer activities of conformationally constrained dibenzo[b,h][1,6] naphthyridine derivatives and Chromeno[3,2-c] quinoline derivatives in the context of cancer drug development and refinement.

Synthesis and antimycobacterial activity of prodrugs of indeno[2,1-c]quinoline derivatives.

Recently we have reported anti-TB properties of a new class of conformationally-constrained indeno[2,1-c]quinolines, which are although considerably active (MIC 0.39-0.78 µg/mL) suffered from intense solubility problems. We thought of improving their bioavailability by prodrugs approach. Accordingly esters of the "Lead" indeno[2,1-c]quinolines 1, 15 and 27 derivatives were synthesized and their prodrug nature at the physiological pH were confirmed. Prodrugs were evaluated for their antimycobacterial activity against Mycobacterium tuberculosis H37Rv by MABA assay to show that they have 2- to 4-fold improved anti-TB activities, increased aqueous solubility and superior selectivity index over their respective parent compounds. MIC of these prodrugs was in the range of <0.20-6.0 µg/mL, and in general, no cytotoxicity was observed in VERO cells.

Novel quinoline and naphthalene derivatives as potent antimycobacterial agents.

We have designed and synthesized both the quinoline and naphthalene based molecules influenced by the unique structural make-up of mefloquine and TMC207, respectively. These compounds were evaluated for their anti-mycobacterial activity against drug sensitive Mycobacterium tuberculosis H37Rv in vitro at single-dose concentration (6.25 microg/mL). The compounds 22, 23, 26 and 27 inhibited the growth of M. tuberculosis H37Rv 99%, 90%, 98% and 91% respectively. Minimum inhibitory concentration of compounds 22, 23, 26 and 27 was found to be 6.25 microg/mL. Our molecular modeling and docking studies of designed compounds showed hydrogen bonding with Glu-61, Tyr-64 and Asn-190 amino acid residues at the putative binding site of ATP synthase, these interactions were coherent as shown by Mefloquine and TMC207, where hydrogen bonding was found with Tyr-64 and Glu-61 respectively. SAR analysis indicates importance of hydroxyl group and nature of substituents on piperazinyl-phenyl ring was critical in dictating the biological activity of newly synthesized compounds.