Herbal Medicine Characterization Perspectives Using Advanced FTIR Sample Techniques – Diffuse Reflectance (DRIFT) and Photoacoustic Spectroscopy (PAS)

Abstract

This study demonstrates the significant potential of the Fourier transform infrared spectroscopy (FTIR) sampling methods: cantilever-enhanced Fourier transform infrared photoacoustic spectroscopy (FTIR PAS) and diffuse reflectance infrared spectroscopy (FTIR DRIFT) in the field of herbal medicines (HM). In the present work we investigated DRIFT and PAS sampling methods because they do not require sample preparation, samples may be opaque or dark, require small amounts, both liquid and solid samples can be measured, and solid samples can be analyzed on a small scale. Experiments conducted prove high sensitivity, reproducibility and capability in combination with an unsupervised multivariate analysis technique to discriminate important characteristics of HM, such as the identification of plant parts, differentiation of samples by types, and determination of the concentration of extractable compounds in HM.

Green Synthesis of Silver Nanoparticles Using Hypericum perforatum L. Aqueous Extract with the Evaluation of Its Antibacterial Activity against Clinical and Food Pathogens

“…The bands near 1617 cm −1 (sometimes 1640 cm −1 ) and near 1734 cm −1 refer to C=O, C-H, and C=O stretching in the aromatic ring. Bands in the range of 1923–2000 cm −1 prove the existence of an aromatic ring, while bands in the range of 2900–2990 cm −1 correspond to C-H stretching and the broad and intense band near 3400 cm −1 indicates the presence of O−H stretching in phenols [ 64 , 66 , 67 ]. The bands at 510 cm −1 and 590 cm −1 are attributed to the metal-ligand frequency stretching which formed due to the interaction between biomolecules and the AgNPs surfaces [ 68 , 69 ].…”

Hydrogel for the Controlled Delivery of Bioactive Components from Extracts of Eupatorium glutinosum Lam. Leaves

“…The Fourier-transform Infrared spectroscopy (FTIR) spectrum of the extracts is helpful in identifying functional groups of the bioactive compounds by analyzing the % transmittance infrared radiation in the region registered. The O-H, -CH, C-O, C=O, C-N, PO3, C-CL, and C=C bonds could correspond to the stretching vibration designated hydroxyl compounds, alcohols, phenols, and aromatic phenols, amino groups, alkanes, or phosphate ions by wavenumber [ 28 ]. EG-methanolic and EG-ethanolic extracts are samples from the same plant with different solvents in the extraction step and showed similar peaks from 3600 cm −1 to 2000 cm −1 (see Figure 3 ).…”

Phytoconstituents profiling and antioxidant potential of Wrightia tinctoria R. Br.

“…The distinctive FTIR PAS and DRIFT spectra were performed for five different herbals including chamomile, silver birch, Hibiscus, peppermint and corn flower. At two spectral areas 850-1850 cm -1 and 2700-3200 cm -1 , the organic matter and bonds in the sample are visible in the FTIR spectra of the examined HMs (Brangule et al, 2020). Multiple functional groups including amines, phenols, alkenes, alcohols, aliphatic compounds, carboxylic acids, esters and carbonyl compounds were identified using FT-IR spectroscopy.…”