Function Oriented Synthesis: Preparation and Initial Biological Evaluation of New A-Ring-Modified Bryologs

Area of Science:

• Medicinal Chemistry
• Organic Synthesis
• Pharmacology

Background:

• Bryostatins are a class of natural products with significant therapeutic potential, particularly in oncology.
• Developing synthetic analogues is crucial for overcoming limitations of natural bryostatin production and improving drug-like properties.
• The A-ring of bryostatins plays a key role in their biological activity and interactions with protein kinase C (PKC).

Purpose of the Study:

• To synthesize and biologically evaluate novel bryostatin A-ring analogues, termed bryologs.
• To establish a versatile synthetic route for generating diverse bryolog structures.
• To investigate the structure-activity relationships (SAR) of these bryologs concerning PKC binding affinity.

Main Methods:

• Design and synthesis of a new series of bryologs utilizing an advanced intermediate for efficient analog generation.
• Evaluation of synthesized bryologs for their binding affinity to protein kinase C (PKC).
• Systematic variation of side chain functionalities to explore their impact on biological activity.

Main Results:

• Successful synthesis of the first bryologs, incorporating a wide range of side chain polarities (alkyl, hydroxyl, carboxyl).
• All synthesized bryologs demonstrated potent binding to protein kinase C, with affinities ranging from 54.7 to 2.4 nM.
• A clear trend was observed where lower side chain polarity correlated with increased PKC binding affinity.

Conclusions:

• The A-ring of bryostatins can be effectively replaced with surrogates (bryologs) to modulate pharmacophore and ADME properties.
• Bryologs represent a promising new class of compounds for developing improved therapeutic agents.
• This study validates the strategy of using A-ring surrogates for fine-tuning the functional characteristics of bryostatin analogues.