Identification of Cortex Eucommiae from different producing areas by FTIR microspectroscopy

Area of Science:

• Analytical Chemistry
• Pharmacognosy
• Spectroscopy

Background:

• Cortex Eucommiae is a vital herb in Traditional Chinese Medicine (TCM).
• Geographical origin significantly impacts the quality and chemical composition of TCM herbs.
• Standardized methods are needed to authenticate the origin of Cortex Eucommiae.

Purpose of the Study:

• To compare FTIR microspectroscopy profiles of Cortex Eucommiae from Anhui (A), Henan (B), and Sichuan (C) provinces.
• To identify spectral markers for distinguishing geographical origins.
• To assess the accuracy of FTIR microspectroscopy combined with hierarchical cluster analysis for classification.

Main Methods:

• Fourier-transform infrared (FTIR) microspectroscopy was employed to analyze samples.
• High-resolution spectra were acquired with high reproducibility.
• Curve fitting analysis was performed to evaluate polysaccharide structures and contents.
• Hierarchical cluster analysis was used in conjunction with FTIR data.

Main Results:

• Obvious differences in band frequencies were observed among samples from different provinces.
• Polysaccharide structures and contents varied significantly, as indicated by curve fitting.
• The ratio A1245/A1328 emerged as a practical factor for distinguishing geographical origins.
• FTIR microspectroscopy combined with hierarchical cluster analysis achieved 89.5% accuracy in identification.

Conclusions:

• FTIR microspectroscopy offers an easy and efficient method for distinguishing Cortex Eucommiae based on geographical origin.
• The technique demonstrates practical applicability for quality control and research in Traditional Chinese Medicine.
• Spectral analysis provides valuable insights into the chemical variations influenced by geographical factors.