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Structure-chiroptical properties relationship in clavams: an experimental and theoretical study
Marek Chmielewski1, Maciej Cierpucha, Patrycja Kowalska
1Institute of Organic Chemistry of the Polish Academy of Sciences, Warsaw, Poland.
Chirality
|October 10, 2007
Summary
This study validates a helicity rule for determining the stereochemistry of clavams using electronic circular dichroism (ECD) spectroscopy. The findings confirm ECD
Area of Science:
- Organic Chemistry
- Spectroscopy
- Computational Chemistry
Background:
- Biological activity of clavams is highly dependent on stereochemistry.
- Accurate determination of absolute stereochemistry is crucial for structure-activity relationship studies of novel penam analogs.
Purpose of the Study:
- To investigate the validity of a proposed empirical helicity rule for clavams.
- To assess the reliability of electronic circular dichroism (ECD) spectroscopy for stereochemical determination in the presence of interfering chromophores.
- To explore the utility of time-dependent density functional theory (TD-DFT) in interpreting ECD spectra.
Main Methods:
- Synthesis of enantiomeric pairs of model compounds with additional chromophores.
- Electronic Circular Dichroism (ECD) spectroscopy.
- Time-dependent Density Functional Theory (TD-DFT) calculations.
Main Results:
- Comparison of experimental ECD spectra with TD-DFT calculations provided interpretation of Cotton effects.
- The helicity rule was confirmed for the studied systems, even with interfering chromophores.
- ECD spectroscopy proved to be a sensitive method for probing the 3D molecular structure of clavams.
Conclusions:
- The empirical helicity rule is valid for determining the absolute stereochemistry of clavams.
- ECD spectroscopy, supported by TD-DFT calculations, is a reliable tool for stereochemical analysis of clavams.
- This approach facilitates structure-activity relationship studies and the development of new bioactive compounds.
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