Determination of the Pectorales species No. 2 and its components identity by infrared spectroscopy of attenuated total reflection

Introduction. The method of IR spectroscopy is applied in assessing the quality of pharmaceutical substances, drugs of synthetic and natural origin, herbal medicines. Attenuated total reflection IR spectroscopy (ATR IR) is the most modern version of IR spectroscopy. At present, the practice of using IR spectroscopy has not found wide implementation in the assessment of the identity of herbal medicines, despite all the advantages of the method. Pectorales species No.2 is a expectorant multicomponent medicinal herbal preparation. The components of the Pectorales species No.2 are the coltsfoot, plantain leaves, and licorice roots. Despite the fact that these herbal medicines are pharmacopoeial and have a rich medical practice, data on their IR-spectra are not presented in the literature. Objective: to determine the characteristics of the identity of Pectorales species No.2 and its components by the method of attenuated total reflection IR spectroscopy. Material and methods: Dry crushed samples of Pectorales species No.2 and its components were studied on a Tensor 37 Fourier spectrometer (Bruker, Germany). Results. Vibrations characteristic of OH-groups, intermolecular hydrogen bonds of polymers, and NH-groups were found in the range of 3700-3020 cm-1. Vibrations of CHn-groups were revealed in the ranges of 3000-2770 cm-1, 1460-1300 cm-1, 900 cm-1. Vibrations of C=O groups of peptides were detected at 1650 cm-1. Vibrations of NH-groups and CN-groups of peptides, ester group of lipids, OH-groups of polysaccharides, O=C-N groups of peptides were found in the area of “fingerprints”. Conclusion. These data may indicate the presence of phenolic compounds, polysaccharides, lipids, and peptides in the samples. Thus, the characteristics of the identity of Pectorales species No. 2, coltsfoot leaves, plantain leaves, and licorice roots were determined by the method of IR spectroscopy.