Kalafungin. II. Chemical transformations and the absolute configuration

Area of Science:

• Medicinal Chemistry
• Organic Chemistry
• Structural Biology

Background:

• Kalafungin is an antifungal agent with a complex polyketide structure.
• Understanding the structure-activity relationship of kalafungin derivatives is crucial for developing new antifungal therapies.
• Previous studies have proposed potential structures for various kalafungin analogues.

Purpose of the Study:

• To confirm the proposed structures of synthesized kalafungin derivatives and analogues.
• To determine the absolute stereochemistry of the active centers in these compounds.
• To provide a basis for further structure-activity relationship studies of kalafungin-based antifungals.

Main Methods:

• Synthesis of kalafungin derivatives and analogues.
• Characterization of compounds using spectroscopic methods (e.g., NMR, Mass Spectrometry).
• Determination of absolute stereochemistry using optical rotatory dispersion (ORD) comparisons.

Main Results:

• The physicochemical properties of the synthesized kalafungin derivatives and analogues align with their proposed structures.
• Optical rotatory dispersion (ORD) analysis definitively established the RRR absolute configuration at the three chiral centers.
• The findings validate the structural assignments for the studied kalafungin compounds.

Conclusions:

• The proposed structures for the kalafungin derivatives and analogues are consistent with experimental data.
• The absolute stereochemistry of the key active centers was unequivocally determined as RRR.
• This study provides critical structural information for the rational design of novel kalafungin-based antifungal agents.