Chiroptical studies of flavanone

Area of Science:

• Analytical Chemistry
• Organic Chemistry
• Computational Chemistry

Background:

• Chiral separation and characterization are crucial for understanding enantiomer properties.
• Traditional methods for determining absolute configuration can be time-consuming and complex.
• Flavanones are an important class of natural products with significant biological activities.

Purpose of the Study:

• To develop and validate an online chiroptical characterization method for flavanone enantiomers.
• To determine the absolute configuration of flavanone enantiomers using hyphenated techniques.
• To compare experimental results with theoretical calculations for enhanced accuracy.

Main Methods:

• High-Performance Liquid Chromatography (HPLC) coupled with Electronic Circular Dichroism (ECD) and Laser Optical Rotation (OR) detection.
• Time-Dependent Density Functional Theory (TD-DFT) calculations for ECD spectrum prediction.
• Density Functional Theory (DFT) calculations for Vibrational Circular Dichroism (VCD) spectrum prediction.
• Fraction collection from repeated HPLC runs for obtaining enantiopure samples.

Main Results:

• Successful on-line chiroptical characterization of both enantiomers of racemic flavanone.
• Assignment of (S)-configuration to ECD(-)310-OR(-)670-flavanone and (R)-configuration to ECD(+)310-OR(+)670-flavanone.
• Theoretical TD-DFT calculations confirmed the assigned absolute configurations.
• VCD spectra analysis further corroborated the absolute configuration determined by on-line HPLC-ECD-OR.

Conclusions:

• The hyphenated HPLC-ECD-OR technique provides an efficient and reliable method for online chiroptical characterization and absolute configuration determination of flavanones.
• Computational chemistry methods (TD-DFT and DFT) are valuable tools for validating experimental findings in chiral analysis.
• This integrated approach enhances stereochemical assignment accuracy and efficiency in chiral compound analysis.