[EN] MACROCYCLIC THERAPEUTIC AGENTS, METHODS OF MANUFACTURE, AND METHODS OF TREATMENT [FR] AGENTS THÉRAPEUTIQUES MACROCYCLIQUES, DES MÉTHODES DE FABRICATION, ET MÉTHODES DE TRAITEMENT
[EN] MACROCYCLIC THERAPEUTIC AGENTS, METHODS OF MANUFACTURE, AND METHODS OF TREATMENT [FR] AGENTS THÉRAPEUTIQUES MACROCYCLIQUES, DES MÉTHODES DE FABRICATION, ET MÉTHODES DE TRAITEMENT
Systematic Chemical Mutagenesis Identifies a Potent Novel Apratoxin A/E Hybrid with Improved in Vivo Antitumor Activity
作者:Qi-Yin Chen、Yanxia Liu、Hendrik Luesch
DOI:10.1021/ml200176m
日期:2011.11.10
Apratoxins are cytotoxic marine natural products that prevent cotranslational translocation early in the secretory pathway. We showed that apratoxins downregulate receptors and growth factor ligands, giving a one–two punch to cancer cells, particularly those that rely on autocrine loops. Through total synthesis, we tested the effects of amino acid substitutions, including alanine scanning, on the downregulation
Improved Total Synthesis and Biological Evaluation of Potent Apratoxin S4 Based Anticancer Agents with Differential Stability and Further Enhanced Activity
Apratoxins are cytotoxic natural products originally isolated from marine cyanobacteria that act by preventing cotranslational translocation early in the secretory pathway to downregulate receptor levels and inhibit growth factor secretion, leading to potent antiproliferative activity. Through rational design and total synthesis of an apratoxin A/ E hybrid, apratoxin S4 (1a), we have previously improved the antitumor activity and tolerability in vivo. Compound la and newly designed analogues apratoxins S7-S9 (1b-d), with various degrees of methylation at C34 (1b,c) or epimeric configuration at C30 (1d), were efficiently synthesized utilizing improved procedures. Optimizations have been applied to the synthesis of key intermediate aldehyde 7 and further include the application of Leighton's silanes and modifications of Kelly's methods to induce thiazoline ring formation in other crucial steps of the apratoxin synthesis. Apratoxin S9 (1d) exhibited increased activity with subnanomolar potency. Apratoxin S8 (lc) lacks the propensity to be deactivated by dehydration and showed efficacy in a human HCT116 xenograft mouse model.