ATR-IR fingerprinting as a powerful method for identification of traditional medicine samples: a report of 20 herbal patterns

Document Type: Original paper


1 Department of Medicinal Chemistry, Shiraz University of Medical Sciences, Shiraz, Iran.

2 Department of Phytopharmaceuticals (Traditional Pharmacy), Faculty of Pharmacy, Shiraz University of Medical Sciences, Shiraz, Iran.

3 Department of Phytopharmaceuticals (Traditional Pharmacy), Faculty of Pharmacy, Shiraz University of Medical Sciences, Shiraz, Iran. Pharmaceutical Sciences Research Center, Shiraz University of Medical Sciences, Shiraz, Iran.


Background and objectives: Attenuated total reflectance-inferared (ATR-IR) spectra can be used as a non-invasive fingerprinting approach in quality control of herbal samples. Methods: Twenty versatile herbal samples were subjected to attenuated total reflectance-inferared (ATR-IR) spectroscopy followed by different clustering methods in order to determine by which method more reasonable classifications would be obtained. Results: All classification methods (K-means, HCA, PCA and SOM) were able to discriminate the two medicinal seeds, Hyocyamus niger and Peganum harmala from other herbal samples. Similarly, the starch samples were clustered in a reasonable method. In HCA, one cluster included three types of starch samples: Zea mays, Oryza sativa and Triticum aestivum. All the four classification methods were able to separate Solanum tuberosum starch from other starch samples. HCA and SOM, were able to classify leaf samples Origanum vulgare and Melissa officinalis belonging to Lamiaceae family, in one category. Crocus sativus and its adulterant Carthamus tinctorius flowers were identified by PCA, HCA and SOM as different categories. Conclusion: The result of this study can be utilized for identification and quality control of traditionally used medicinal plant samples in an unknown sample powder. Such data could be the basis for preparing a data bank on Iranian medicinal samples which in turn is used as a simple, fast and reliable method for characterization of herbal powders in Pharmacopoeias.


[1]  Cordell GA, Colvard MD. Natural products and traditional medicine: turning on a paradigm. J Nat Prod. 2012; 75(3) :514-525.

[2]  Kokalj M, Kolar J, Trafela  T, Kreft S. Finding the most appropriate IR technique for plant species identification. Planta Med. 2011; 77: 38.

[3]  Turner NW, Cauchi M, Piletska EV, Preston C, Piletsky SA. Rapid qualitative and quantitative analysis of opiates in extract of poppy head via FTIR and chemometrics: towards in-field sensors. Biosens Bioelectron. 2009; 24(11): 3322-3328.

[4]  Lai Y, Ni Y, Kokot S. Classification of raw and roasted Semen Cassiae samples with the use of Fourier transform infrared fingerprints and least squares support vector machines. Appl Spectrosc. 2010; 64(6): 649-656.

[5]  Deconinck E, Cauwenbergh T, Bothy JL, Custers D, Courselle P, De Beer JO. Detection of sibutramine in adulterated dietary supplements using attenuated total reflectance-infrared spectroscopy. J Pharmaceut Biomed. 2014; 100: 279-283.

[6]  Samadi, Theodoridou K, Yu P. Detect the sensitivity and response of protein molecular structure of whole canola seed (yellow and brown) to different heat processing methods and relation to protein utilization and availability using ATR-FT/IR molecular spectroscopy with chemometrics. Spectrochim Acta A. 2013; 105: 304-313.

[7]  Ghasemi Dehkordi N. Most commonly used medicinal plants: microscopic and macroscopic quality control. Isfahan: Chaharbagh Pub., 2014.

[8]  Upton R, Graff A, Jolliffe G, Länger R, Williamson E. American herbal pharmacopoeia: botanical pharmacognossy-microscopic characterization of botanical medicines. Boca Raton: CRC Press, 2011.

[9]  Eschrich W. Pulver-atlas der drogen der deutschsprachigen arzneibücher. Stuttgart: Deutscher Apotheker Verlag, 2003.

[10]  Li T, Zhang H. Application of microscopy in authentication of traditional Tibetan medicinal plants of five Rhodiola (Crassulaceae) alpine species by comparative anatomy and micromorphology. Microsc Res Techniq. 2008; 71(6): 448-458.

[11]  Steinley D. K-means clustering: a half-century synthesis.  Br J Math Stat Psychol. 2006; 59(Pt 1): 1-34.

[12]  Li HJ, Jiang Y, Li P. Characterizing distribution of steroidal alkaloids in Fritillaria spp. and related compound formulas by liquid chromatography-mass spectrometry combined with hierarchial cluster analysis. J Chromatogr A. 2009; 1216(11): 2142-2149.

[13]  Sundaram J, Park B, Hinton A, Yoon SC, Windham WR, Lawrence KC. Classification and structural analysis of live and dead Salmonella cells using Fourier transform infrared spectroscopy and principal component analysis. J Agric Food Chem. 2012; 60(4): 991-1004.

[14]  Milano Chemometrics and QSAR Research. Kohonen and CP-ANN toolbox for MATLAB, version 2.0.