Direct deposition GC/IR techniques in natural product identification

Area of Science:

• Analytical Chemistry
• Natural Product Chemistry
• Spectroscopy

Background:

• Gas chromatography/mass spectrometry (GC/MS) is a standard for volatile natural product identification.
• GC/MS analysis primarily provides information on molecular weight and fragmentation patterns.
• Orthogonal analytical methods are crucial for comprehensive structure elucidation.

Purpose of the Study:

• To highlight the utility of coupled gas chromatography/direct deposition Fourier transform infrared (GC/DD-FTIR) spectroscopy for natural product analysis.
• To demonstrate how GC/DD-FTIR provides complementary data to GC/MS.
• To showcase the potential of combining GC/DD-FTIR with computational methods for enhanced structure determination.

Main Methods:

• Coupled gas chromatography/direct deposition Fourier transform infrared (GC/DD-FTIR) spectroscopy.
• Analysis of functional groups and C-C double bonds using FTIR data.
• Integration with gas chromatography/mass spectrometry (GC/MS) for comparative analysis.
• Application of Density Functional Theory (DFT) calculations.

Main Results:

• GC/DD-FTIR yields orthogonal information to GC/MS, particularly regarding functional groups and C-C double bonds.
• The method is effective for the structure elucidation of trace volatile natural products.
• Combining GC/DD-FTIR with DFT calculations enhances the reliability of structural assignments.

Conclusions:

• GC/DD-FTIR is an underused yet powerful technique for volatile natural product identification.
• This spectroscopic method offers valuable complementary data to established techniques like GC/MS.
• The synergy between GC/DD-FTIR and DFT calculations significantly advances the field of natural product structure elucidation.