- Structure-activity relationships for ferriprotoporphyrin IX association and β-hematin inhibition by 4-aminoquinolines using experimental and ab initio methods
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In order to probe structure-activity relationships of association with ferriprotoporphyrin IX (log K) and inhibition of β-hematin formation, a series of 4-aminoquinolines with varying substituents at the 7-position (X) have been synthesized. These have been further elaborated by introduction of two different R groups on the 4-amino nitrogen atom in the form of methyl (R = Me) and ethylamine (R = EtNH2) side chains. Data for a previously investigated series containing an N,N-diethyl-ethylamine side chain were also compared with the findings of this study. Experimentally, log K values for the simple 4-aminoquinoline series (R = H) were found to correlate with the hydrophobicity constant (π) of the group X. The log K values for the series with R = Me and EtNH2 were found to correlate with those of the series with R = H. The log of the 50% β-hematin inhibitory activity (log BHIA50) was found to correlate with log K and either meta (σm) or para (σp) Hammett constants for the series with R = Me and EtNH2, but not the simple series with R = H. To further improve predictability, correlations with ab initio electrostatic parameters, namely Mulliken and CHelpG charges were investigated. The best correlations were found with CHelpG charges which indicated that log K values can be predicted from the charges on atom H-8 and the group X in the quinolinium species computed in vacuum, while log BHIA50 values can be predicted from the CHelpG charges on C-7, C-8 and N-1 for the neutral species in vacuum. These correlations indicate that association and inhibition of β-hematin formation are separately determined. They also suggest that electron withdrawing groups at the 7-position, but not necessarily hydrophobic groups are required for hemozoin inhibition. The upshot is that the correlations imply that considerably more hydrophilic hemozoin inhibitors are feasible.
- Nsumiwa, Samkele,Kuter, David,Wittlin, Sergio,Chibale, Kelly,Egan, Timothy J.
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p. 3738 - 3748
(2013/07/19)
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- Preparation of quinoline hexose analogs as novel chloroquine-resistant malaria treatments (1). Synthesis of 4-hydroxyquinoline-β-glucosides
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Quinoline hexose analogs are expected to be useful as novel agents for treatment of chloroquine-resistant malaria. Here, we report preparation of 4-hydroxy quinoline-β-glucosides from anilines in 4 steps.
- Suzuki, Hiroshi,Aly, Nagwa S. M.,Wataya, Yusuke,Kim, Hye-Sook,Tamai, Ikumi,Kita, Masaki,Uemura, Daisuke
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p. 821 - 824
(2008/02/13)
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- Oxazolo, thiazolo and selenazolo [4,5-c]-quinolin-4-amines and analogs thereof
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Thiazolo-, oxazolo- and selenazolo[4,5-c]quinolin-4-amines and analogs thereof are described including methods of manufacture and the use of novel intermediates. The compounds are immunomodulators and induce cytokine biosynthesis, including interferon and/or tumor biosynthesis, necrosis factor, and inhibit the T-helper-type 2 immune response. The compounds are further useful in the treatment of viral and neoplastic diseases.
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- Thioquinolone compounds which have useful pharmaceutical activity
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Disclosed is a thioquinolone derivative which exhibits highly selective antibacterial activity against Helicobacter pylori.
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- Structure-activity relationships for antiplasmodial activity among 7- substituted 4-aminoquinolines
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Aminoquinolines (AQs) with diaminoalkane side chains (-HNRNEt2) shorter or longer than the isopentyl side chain [-HNCHMe(CH2)3NEt2] of chloroquine are active against both chloroquine-susceptible and -resistant Plasmodium falciparum. (De, D.; et al. Am. J. Trop. Med. Hyg. 1996, 55, 579-583). In the studies reported here, we examined structure-activity relationships (SARs) among AQs with different N,N-diethyldiaminoalkane side chains and different substituents at the 7-position occupied by Cl in chloroquine. 7-Iodo- and 7- bromo-AQs with diaminoalkane side chains [-HN(CH2)2NEt2, -HN(CH2)3NEt2, or -HNCHMeCH2NEt2] were as active as the corresponding 7-chloro-AQs against both chloroquine-susceptible and -resistant P. falciparum (IC50s of 3-12 nM). In contrast, with one exception, 7-fluoro-AQs and 7-trifluoromethyl-AQs were less active against chloroquine-susceptible P. falciparum (IC50s of 15-50 nM) and substantially less active against chloroquine-resistant P. falciparum (IC50s of 18-500 nM). Furthermore, most 7-OMe-AQs were inactive against both chloroquine-susceptible (IC50s of 17-150 nM) and -resistant P. falciparum (IC50s of 90-3000 nM).
- De, Dibyendu,Krogstad, Frances M.,Byers, Larry D.,Krogstad, Donald J.
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p. 4918 - 4926
(2007/10/03)
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