Antiradical Activity of Extractive Substances of Ledum polustre L., Growing in the Krasnoyarsk Territory

Abstract

Objective: In model reactions with a free stable 2,2-diphenyl-1-picrylhydrazyl radical, the antiradical activity (ARA) of extractive substances of wild rosemary (Ledum palustre L.) growing in the Krasnoyarsk Territory was studied: aqueous-alcoholic extracts with an alcohol content of 20, 40, and 70%, water and alcohol extracts and essential oil. Methods: Whole essential oil obtained by exhaustive hydrosteam distillation for 8 h. The component composition of the essential oil was determined by chromato-mass spectrometry using a data bank on mass spectra and on the analysis of linear retention indices. Results and Discussion: At least 35 individual compounds were identified in the essential oil and their quantitative content was determined. The leaves of wild rosemary collected at the beginning of flowering in early June in the Partizansky district of the Krasnoyarsk Territory were used as raw materials. The extracts were obtained using a sample of air-dry raw materials in the amount of 1.00 g, the extraction hydromodule was 1 : 100, the extraction time was 1 h. The results of the DPPH test showed that the antiradical activity of the obtained extracts changes in the following order: essential oil > 40% extract > 70% extract > 20% extract > aqueous extract. Moreover, the essential oil of wild rosemary has an ARA value of 82.7% even when diluted 1 : 10. The obtained extracts were studied by electron spectroscopy in the UV region. It is shown that the extracts contain phenolic compounds represented by phenolcarboxylic acids and flavonoids. In the extracts obtained, the total content of phenolic compounds was determined (by reaction with the Folin–Ciocalteu reagent), which is 0.52–1.05 wt.% in terms of gallic acid. Moreover, this value passes through a maximum in the case of 40% alcohol extract. Conclusions: By reaction with aluminum chloride, the total content of flavonoids in the extracts was determined. It was found that the content of flavonoids in the extracts is 0.73–2.00 wt. % in terms of routine. The maximum content of flavonoids was found in 70% alcohol extract. It is shown that the ARA value correlates well with the total content of phenolic compounds - the correlation coefficient is 0.9512, and no correlation is observed with the total content of flavonoids.