Assessing essential oil composition in Cinnamomum cassia leaves from different regions of China using GC-MS and FTIR spectroscopy

In this study, volatile compounds from Cinnamomum cassia Presl. leaves from different regions of China were identified using gas chromatography coupled with mass spectrometry (GC-MS) and Fourier-transform infrared (FTIR) spectroscopy combined with chemometrics. The results showed that the essential oil yields greatly varied across regions, with the density of oil cells at the accumulation and saturation stages playing a key role in this yield. GC-MS analysis revealed a higher content of trans-cinnamaldehyde in samples from the Xijiang River basin (No. 1–8) than in those from Baise Guangxi (No. 9). Variable importance in projection analysis identified five differential marker components for assessing the geographical origin of C. cassia leaves: trans-cinnamaldehyde, acetophenone, cis-cinnamaldehyde, camphor, and α-thujene. Hierarchical cluster analysis, similarity evaluation, and principal component analysis from FTIR fingerprinting indicated that essential oil compositions of samples No. 1–6 from the Xijiang River basin were closely related. In contrast, the Baise sample (Western Guangxi) significantly differed from the other eight, likely due to the geographical distance. Our results indicate that the methods employed are effective for determining the geographical distribution and assessing the quality of raw cinnamon in herbal medicine.