Function-Oriented Synthesis: Design, Synthesis, and Evaluation of Highly Simplified Bryostatin Analogues

Area of Science:

• Medicinal Chemistry
• Organic Synthesis
• Molecular Pharmacology

Background:

• Bryostatins are complex natural products with significant therapeutic potential, particularly as modulators of protein kinase C (PKC).
• The intricate structure of bryostatins presents challenges for large-scale synthesis and drug development.
• Understanding structure-activity relationships is crucial for designing simplified analogues with retained or improved biological function.

Purpose of the Study:

• To design, synthesize, and evaluate novel, structurally simplified analogues of bryostatin 1.
• To investigate the impact of replacing bryostatin's A- and B-rings with a glutarate linker on PKC isoform affinities and activity.
• To demonstrate the utility of function-oriented synthesis in creating accessible drug leads.

Main Methods:

• Function-oriented synthesis strategy was employed to design analogues.
• Synthesis of two bryostatin analogues: one without and one with a C26-methyl group, featuring a glutarate linker.
• Evaluation of protein kinase C (PKC) isoform affinities using binding assays (Ki determination).
• Assessment of PKC translocation kinetics in vitro.

Main Results:

• The analogue without the C26-methyl group displayed bryostatin-like binding affinities (Ki < 5 nM) to several PKC isoforms.
• The analogue with the C26-methyl group showed significantly reduced PKC affinities (up to 180-fold less potent).
• The potent analogue demonstrated bryostatin-like PKC translocation kinetics, indicating efficient cell permeation and target engagement.

Conclusions:

• Function-oriented synthesis effectively reduced structural complexity while preserving biological activity.
• Simplified bryostatin analogues can retain potent PKC modulation capabilities.
• These findings provide promising new leads for developing therapeutics targeting PKC-related diseases.