藏荆芥和康藏荆芥的红外光谱鉴别OA

To achieve reliable discrimination between Nepeta hemsleyana and Nepeta prattii,this study,employed Fourier transform infrared spectroscopy(FTIR)combined with second-derivative infrared spectroscopy to establish a rapid and specific identification method.The original infrared spectra of Nepeta hemsleyana,Nepeta prattii,and E,Z-nepetalactone were acquired using an FTIR spectrometer.Spectral data were preprocessed using OMNIC 9.0 software,and the spectra were visualized using OriginPro 2024.A systematic comparison of the infrared spectral characteristics and differences between the two species was conducted.The results showed that the original FTIR spectra of Nepeta hemsleyana and Nepeta prattii were generally similar,with nine common absorption peaks identified at 3 725,3 704,3 420,2 926,2 853,1 652,1 260,1 158,and 1 065 cm-1.However,notable differences in peak intensities were observed at 3 420 and 1 652 cm-1.Comparison with the reference spectrum of E,Z-nepetalactone confirmed the presence of this compound in both species,with stronger characteristic absorption peaks observed in Nepeta hemsleyana,suggesting a relatively higher content of E,Z-nepetalactone.Furthermore,second-derivative spectra in the ranges of 1 800～1 200 cm-1 and 1 200～400 cm-1 revealed significant differences between the two species in carbonyl groups,double bonds,and fingerprint regions,enabling effective discrimination between them.The FTIR-based method established in this study is rapid,non-destructive,and highly reproducible.It provides a novel technical approach for the rapid identification of closely related and easily confused Nepeta species used in Xizang's medicine,thereby addressing the limitations of traditional identification methods.