4-N-, 4-S-, and 4-O-Chloroquine Analogues: Influence of Side Chain Length and Quinolyl Nitrogen pKa on Activity vs Chloroquine Resistant Malaria
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- 作者：Jayakumar K. Natarajan ; John N. Alumasa ; Kimberly Yearick ; Kekeli A. Ekoue-Kovi ; Leah B. Casabianca ; Angel C. de Dios ; Christian Wolf ; Paul D. Roepe
- 刊名：Journal of Medicinal Chemistry
- 出版年：2008
- 出版时间：June 26, 2008
- 年：2008
- 卷：51
- 期：12
- 页码：3466 - 3479
- 全文大小：963K
- 年卷期：v.51,no.12(June 26, 2008)
- ISSN：1520-4804
文摘
Using predictions from heme−quinoline antimalarial complex structures, previous modifications of chloroquine (CQ), and hypotheses for chloroquine resistance (CQR), we synthesize and assay CQ analogues that test structure−function principles. We vary side chain length for both monoethyl and diethyl 4-N CQ derivatives. We alter the pKa of the quinolyl N by introducing alkylthio or alkoxy substituents into the 4 position and vary side chain length for these analogues. We introduce an additional titratable amino group to the side chain of 4-O analogues with promising CQR strain selectivity and increase activity while retaining selectivity. We solve atomic resolution structures for complexes formed between representative 4-N, 4-S, and 4-O derivatives vs μ-oxo dimeric heme, measure binding constants for monomeric vs dimeric heme, and quantify hemozoin (Hz) formation inhibition in vitro. The data provide additional insight for the design of CQ analogues with improved activity vs CQR malaria.