Number Of Flavonols Research Articles

Содержание фенольных соединений индивидуальных растений трех видов рода Bistorta (L.) Scop.

Plants of the Bistorta genus manifest themselves as a rich source of phenolic compounds, exhibiting antioxidant, anti-inflammatory, antitumor effects, etc. One of the important research tasks in this connection involves the identification of the plant organ having the maximum concentration of the target substances, as well as the comparison of the content of secondary metabolites in plants of different species of the genus. The aim of this work was to study the content of phenolic compounds in the organs of individual plants of three species of the Bistorta genus growing in Siberia: B. officinalis, B. vivipara and B. attenuata. The total content of phenolic compounds in water-ethanol plant extracts was determined by spectrophotometric methods. The results of the study revealed a high level of variability of flavonols and catechins in the organs of the studied species. The average variability of tannins is noted in the inflorescences of B. attenuata and B. vivipara, as well as in the leaves and rhizomes of B. officinalis. A decrease to low variability is observed in the leaves of B. vivipara. An uneven distribution of phenolic compounds in the organs of different plant species was established. B. attenuata plants accumulate the largest number of flavonols in inflorescences, while B. officinalis and B. vivipara demonstrate the maximum value in the leaves. B. officinalis contains more catechins in rhizomes, while B. attenuata and B. vivipara demonstrate the highest catechin value in inflorescences. B. officinalis presents a unique plant species with an extremely high content of catechins (10.5%) and tannins (29.8%) in the underground organs. B. attenuata differs from the other two species in having a lower catechin content in all organs, but the highest number of flavonols in inflorescences (10.7%). The unique character of accumulation of substances in plant organs characterising each species should be taken into account when collecting raw materials for medicinal use.

THE INFLUENCE OF LIGHT OF DIFFERENT SPECTRAL REGIONS ON THE SYNTHESIS OF PHENOLIC COMPOUNDS IN GHERKIN SEEDLINGS IN RELATION TO PHOTOMORPHOGENESIS I BIOSYNTHESIS OF PHENOLIC COMPOUNDS

1) Dark-grown gherkin seedlings contain the sugar derivatives of p-coumaric acid and ferulic acid, present in both the cotyledons and hypocotyls, and a number of flavonols, occurring only in the cotyledons. Exposure of these seedlings to light results in an increase in the accumulation of these phenolic compounds after a lag of 1 1/2 to 2 hours. 2) The responsivity of this effect to radiation in the blue and far-red wavelength regions is higher than to red light. Both photoresponse I, the “high-energy reaction”, and photoresponse II, the phytochrome reaction, seem to be involved. 3) The distribution pattern of the phenolics in the hypocotyl changes in the course of the irradiation: An initial increase in the concentration of hydroxycinnamic acids is followed by a decrease, particularly in the apical part. The ratio of ferulic acid to p-coumaric acid increases and is always higher in the lower part of the hypocotyl than in the apical part. 4) The accumulation of hydroxycinnamic acids in the hypocotyl in red and far-red light is largely dependent on the presence of the cotyledons. In blue light there is also a considerable synthesis when the cotyledons are excised.

The factors that affect alkali colour reactions of flavonols: A study of flavonols of uncommon types

In order to get fuller information on the influence of hydroxyl groups on alkali colour reactions a number of flavonols of types uncommon in Nature have been prepared and examined. Though the correlation between structure and alkali colour reactions is complex, when applied with care the reactions can be used for diagnostic purposes. The alkali colour reactions of the flavonols with 2′∶3′ and 2′∶3′∶4′ disposition of hydroxyl groups are not prominent and their fluorescence properties are also very feeble.