Novel squalestatins produced by biotransformation

Area of Science:

• Biotechnology and Microbial Chemistry
• Drug Discovery and Development
• Enzyme Inhibition Studies

Background:

• Squalestatin 1 is a potent inhibitor of squalene synthase, a key enzyme in cholesterol biosynthesis.
• Microbial biotransformation offers a sustainable approach for modifying complex natural products like squalestatin 1.
• Understanding structure-activity relationships is crucial for optimizing drug candidates.

Purpose of the Study:

• To explore the microbial modification of squalestatin 1 using various microorganisms.
• To identify and characterize the biotransformation products of squalestatin 1.
• To evaluate the squalene synthase inhibitory activity of the resulting metabolites.

Main Methods:

• Screening of diverse microbial strains for biotransformation capabilities.
• Fermentation of squalestatin 1 with selected actinomycetes and fungi.
• Isolation, purification, and structural elucidation of biotransformation products using chromatographic and spectroscopic techniques.
• In vitro assays to determine squalene synthase inhibitory activity.

Main Results:

• Two actinomycete strains (S15106, S15138) produced hydroxylated derivatives of squalestatin 1 on the side chain, with some lacking the acetyl ester.
• Several microbial strains hydrolyzed ester functionalities, yielding squalestatins 2 and 3.
• Fusarium sp. F13945 generated a 3-methyl ester derivative and a farnesoic acid derivative.
• All identified biotransformation products exhibited significant squalene synthase inhibitory activity.

Conclusions:

• Microbial biotransformation is effective in generating novel squalestatin 1 analogs with modified side chains and ester groups.
• The observed modifications did not abolish, and potentially retained, the potent squalene synthase inhibitory activity.
• These findings support the potential of microbial-derived squalestatin analogs in therapeutic applications targeting cholesterol biosynthesis.