Asymmetric Synthesis and Biological Evaluation of Platensilin, Platensimycin, Platencin, and Their Analogs via a Bioinspired Skeletal Reconstruction Approach

J Am Chem Soc. 2024 Jul 17;146(28):18967-18978. doi: 10.1021/jacs.4c02256. Epub 2024 Jul 8.

Abstract

Platensilin, platensimycin, and platencin are potent inhibitors of β-ketoacyl-acyl carrier protein synthase (FabF) in the bacterial and mammalian fatty acid synthesis system, presenting promising drug leads for both antibacterial and antidiabetic therapies. Herein, a bioinspired skeleton reconstruction approach is reported, which enables the unified synthesis of these three natural FabF inhibitors and their skeletally diverse analogs, all stemming from a common ent-pimarane core. The synthesis features a diastereoselective biocatalytic reduction and an intermolecular Diels-Alder reaction to prepare the common ent-pimarane core. From this intermediate, stereoselective Mn-catalyzed hydrogen atom-transfer hydrogenation and subsequent Cu-catalyzed carbenoid C-H insertion afford platensilin. Furthermore, the intramolecular Diels-Alder reaction succeeded by regioselective ring opening of the newly formed cyclopropane enables the construction of the bicyclo[3.2.1]-octane and bicyclo[2.2.2]-octane ring systems of platensimycin and platencin, respectively. This skeletal reconstruction approach of the ent-pimarane core facilitates the preparation of analogs bearing different polycyclic scaffolds. Among these analogs, the previously unexplored cyclopropyl analog 47 exhibits improved antibacterial activity (MIC80 = 0.0625 μg/mL) against S. aureus compared to platensimycin.

MeSH terms

  • Adamantane* / analogs & derivatives
  • Adamantane* / chemical synthesis
  • Adamantane* / chemistry
  • Adamantane* / pharmacology
  • Aminobenzoates* / chemical synthesis
  • Aminobenzoates* / chemistry
  • Aminobenzoates* / pharmacology
  • Aminophenols* / chemical synthesis
  • Aminophenols* / chemistry
  • Aminophenols* / pharmacology
  • Anilides* / chemical synthesis
  • Anilides* / chemistry
  • Anilides* / pharmacology
  • Anti-Bacterial Agents / chemical synthesis
  • Anti-Bacterial Agents / chemistry
  • Anti-Bacterial Agents / pharmacology
  • Cycloaddition Reaction
  • Enzyme Inhibitors / chemical synthesis
  • Enzyme Inhibitors / chemistry
  • Enzyme Inhibitors / pharmacology
  • Microbial Sensitivity Tests
  • Molecular Structure
  • Polycyclic Compounds* / chemical synthesis
  • Polycyclic Compounds* / chemistry
  • Polycyclic Compounds* / pharmacology
  • Staphylococcus aureus / drug effects
  • Stereoisomerism

Substances

  • platensimycin
  • Aminophenols
  • Polycyclic Compounds
  • platencin
  • Adamantane
  • Anilides
  • Aminobenzoates
  • Anti-Bacterial Agents
  • Enzyme Inhibitors