- A concise synthesis of indoloquinoline skeletons applying two consecutive Pd-catalyzed reactions
-
The indoloquinoline alkaloids cryptolepine (1), neocryptolepine (2), isocryptolepine (3), and isoneocryptolepine (4) are important tools in traditional medicine. Now, their precursors 1a-4a were synthesized in two steps starting from the corresponding bromo-iodoquinolines. Our strategy is based on palladium-catalyzed reactions, applying regioselective Buchwald-Hartwig amination on 2,3- and 3,4-dihaloquinolines followed by an intramolecular Heck-type reaction. Both steps were carried out under microwave irradiation.
- Bogányi, Borbála,Kámán, Judit
-
p. 9512 - 9519
(2013/10/08)
-
- Identification, design and biological evaluation of bisaryl quinolones targeting Plasmodium falciparum type II NADH:Quinone oxidoreductase (PfNDH2)
-
A program was undertaken to identify hit compounds against NADH:ubiquinone oxidoreductase (PfNDH2), a dehydrogenase of the mitochondrial electron transport chain of the malaria parasite Plasmodium falciparum. PfNDH2 has only one known inhibitor, hydroxy-2-dodecyl-4-(1H)-quinolone (HDQ), and this was used along with a range of chemoinformatics methods in the rational selection of 17 000 compounds for high-throughput screening. Twelve distinct chemotypes were identified and briefly examined leading to the selection of the quinolone core as the key target for structure-activity relationship (SAR) development. Extensive structural exploration led to the selection of 2-bisaryl 3-methyl quinolones as a series for further biological evaluation. The lead compound within this series 7-chloro-3-methyl-2-(4-(4-(trifluoromethoxy)benzyl)phenyl) quinolin-4(1H)-one (CK-2-68) has antimalarial activity against the 3D7 strain of P. falciparum of 36 nM, is selective for PfNDH2 over other respiratory enzymes (inhibitory IC50 against PfNDH2 of 16 nM), and demonstrates low cytotoxicity and high metabolic stability in the presence of human liver microsomes. This lead compound and its phosphate pro-drug have potent in vivo antimalarial activity after oral administration, consistent with the target product profile of a drug for the treatment of uncomplicated malaria. Other quinolones presented (e.g., 6d, 6f, 14e) have the capacity to inhibit both PfNDH2 and P. falciparum cytochrome bc1, and studies to determine the potential advantage of this dual-targeting effect are in progress.
- Pidathala, Chandrakala,Amewu, Richard,Pacorel, Bénédicte,Nixon, Gemma L.,Gibbons, Peter,Hong, W. David,Leung, Suet C.,Berry, Neil G.,Sharma, Raman,Stocks, Paul A.,Srivastava, Abhishek,Shone, Alison E.,Charoensutthivarakul, Sitthivut,Taylor, Lee,Berger, Olivier,Mbekeani, Alison,Hill, Alasdair,Fisher, Nicholas E.,Warman, Ashley J.,Biagini, Giancarlo A.,Ward, Stephen A.,O'Neill, Paul M.
-
p. 1831 - 1843
(2012/05/04)
-