Fast screening of some flavonoids content in raw plant materials: Opportunities of 1H NMR spectroscopy

Environmental monitoring and assessment of the prospects for extracting biologically active substances (BAS) from various types of plant biomass requires the development of simple and fast methods for measuring their content in raw materials. A new approach for measuring the content of various flavonoids groups in plant raw material using 1H NMR spectroscopy has been developed, which allows to characterize its resource capabilities and study the effects on their composition different environmental factors without complex sample preparation and standard samples. © The Authors, published by EDP Sciences, 2020

NMR-spectroscopic study of conjugation effects. 8.13C NMR spectra of p-substituted anisoles, thioanisoles, and selenoanisoles

1. According to the data from13C NMR spectra, the effective conformation of anisoles, thioanisoles, and selenoanisoles is determined both by "methyl-ring" spatial interactions as well as by p, π conjugation of the O, S, and Se with the aromatic fragment which varies depending on the electronic nature of the p substituent in the ring. 2. Acceptor p substituents enhance, and donor p substituents reduce, the coplanarity of the molecules and, moreover, the greatest sensitivity to this effect is characteristic of the seleno- and thioanisoles. © 1980 Plenum Publishing Corporation

NMR-spectroscopic study of conjugation effects. 8.13C NMR spectra of p-substituted anisoles, thioanisoles, and selenoanisoles

1. According to the data from13C NMR spectra, the effective conformation of anisoles, thioanisoles, and selenoanisoles is determined both by "methyl-ring" spatial interactions as well as by p, π conjugation of the O, S, and Se with the aromatic fragment which varies depending on the electronic nature of the p substituent in the ring. 2. Acceptor p substituents enhance, and donor p substituents reduce, the coplanarity of the molecules and, moreover, the greatest sensitivity to this effect is characteristic of the seleno- and thioanisoles. © 1980 Plenum Publishing Corporation

NMR-spectroscopic study of conjugation effects. 8.13C NMR spectra of p-substituted anisoles, thioanisoles, and selenoanisoles

1. According to the data from13C NMR spectra, the effective conformation of anisoles, thioanisoles, and selenoanisoles is determined both by "methyl-ring" spatial interactions as well as by p, π conjugation of the O, S, and Se with the aromatic fragment which varies depending on the electronic nature of the p substituent in the ring. 2. Acceptor p substituents enhance, and donor p substituents reduce, the coplanarity of the molecules and, moreover, the greatest sensitivity to this effect is characteristic of the seleno- and thioanisoles. © 1980 Plenum Publishing Corporation