Polyphenols content determination in herbals extracts

Abstract

Some plants  products are a valuable source biologically active substances (BAS), their using on the ordinary diet allows for preventive and therapeutic action in various deseases pathological conditions of the body. Researchers interesting polyphenolic antioxidants among BAS. The method of infrared spectrophotometry (IR-spectroscopy) was applied to detect polyphenols in bark, roots and leaves plants extracts, polyphenolic compounds functional groups were identified: hydroxyl (-OH) and carboxyl (-COOH), the content of which in molecules of various chemical substances transmitted by identical absorption bands. In the spectra of vegetable extracts of oak bark and viburnum, bearberry leaves in the region of 3400 cm-1, there are wide absorption bands of high intensity, which are related to the frequencies of associated OH bonds, the bands at 3606– 3622 cm-1 (υOH) are due to free hydroxyls, and at 3626-3654 cm-1 (υОН) – spatially shielded. In the composition of extracts of bark and leaves of medicinal plants, ethers of phenol carbonic and hydroxycinnamic acids (1500 cm-1 1140-1000 cm-1 υС-O-С, υС = С-О-С) are found. The bands in the region of 1600-1700 cm-1 are characteristic of the carboxyl groups of γ-pyrons of the flavonoid cycle and quinone. According to the heights of the identified peaks, the content of phenolic compounds in the extracts is reduced in the following order: extracts of bearberry leaves (Arctostaphylos Uva-ursi) > Oak bark (Quercus cortex) > Viburnum bark (Cortex Viburni) > Devyasela roots (Inulae Rhizomata Et Radices) > Krovochlabky roots (Rhizoma et radix Sanguisorbae).