Synthesis and structure-activity correlation of natural-product inspired cyclodepsipeptides stabilizing F-actin.
The fundamental role played by actin in the regulation of eukaryotic cell maintenance and motility renders it a primary target for small-molecule intervention. In this arena, a class of potent cytotoxic cyclodepsipeptide natural products has emerged over the last quarter-century to stimulate the fields of biology and chemistry with their unique actin-stabilizing properties and complex peptide-polyketide hybrid structures. Despite considerable research effort, a structural basis for the activity of these secondary metabolites remains elusive, not least for the lack of high-resolution structural data and a reliable synthetic route to diverse compound libraries. In response to this, an efficient solid-phase approach has been developed and successfully applied to the total synthesis of jasplakinolide and chondramide C and diverse analogues. The key macrocylization step was realized using ruthenium-catalyzed ring-closing metathesis (RCM) that in the course of a library synthesis produced discernible trends in metathesis reactivity and E/Z-selectivity. After optimization, the RCM step could be operated under mild conditions, a result that promises to facilitate the synthesis of more extensive analogue libraries for structure-function studies. The growth inhibitory effects of the synthesized compounds were quantified and structure-activity correlations established which appear to be in good alignment with relevant biological data from natural products. In this way a number of potent unnatural and simplified analogues have been found. Furthermore, potentially important stereochemical and structural components of a common pharmacophore have been identified and rationalized using molecular modeling. These data will guide in-depth mode-of-action studies, especially into the relationship between the cytotoxicity of these compounds and their actin-perturbing properties, and should inform the future design of simplified and functionalized actin stabilizers as well.
Max-Planck-Institut für molekulare Physiologie, Otto-Hahn-Strasse 11, 44227 Dortmund, Germany.
René
R
Tannert
Lech-Gustav
LG
Milroy
Bernhard
B
Ellinger
Tai-Shan
TS
Hu
Hans-Dieter
HD
Arndt
Herbert
H
Waldmann
D000199:Actins / Q000737:chemistry*; D000818:Animals; D000970:Antineoplastic Agents / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D001685:Biological Factors / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D002460:Cell Line; D049109:Cell Proliferation / Q000187:drug effects; D018360:Crystallography, X-Ray; D047630:Depsipeptides / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004354:Drug Screening Assays, Antitumor; D006801:Humans; D051379:Mice; D008958:Models, Molecular; D008968:Molecular Conformation; D055550:Protein Stability / Q000187:drug effects; D013237:Stereoisomerism; D013329:Structure-Activity Relationship
D000199:Actins; D000970:Antineoplastic Agents; D001426:Bacterial Proteins; D001685:Biological Factors; D047630:Depsipeptides; C097821:chondramide C; C057531:jasplakinolide