Assessment of variability in the content of phenolic compounds in above‐ground organs of natural samples of Silybum marianum (l.) Gaertn L.

The aim of the work is to study the content of flavonoids and anthocyanins in the above‐ground organs of Silybum marianum (L.) Gaertn L., growing in natural conditions, and to assess their accumulation as this depends on the conditions of the place of growth (altitude above sea level) in Dagestan (Russia). In the flowering phase of 2013, the above‐ground part of the plant was collected from natural populations and using the generally accepted differential spectrometric technique. This showed that the total content of flavonoids and anthocyanins in all organs, regardless of the place of collection, is 0.22% – 3.07% in terms of rutin, and 0.03% – 0.26% in terms of 3‐glucoside of cyanidin, respectively. Phenolic compounds were noted in all parts of the plants: their maximum content being in the leaves and inflorescences, while the minimum is in the stems. The dependence of the total content of flavonoids and anthocyanins on the altitude factor is multi‐vectoral; in most cases the connection is insignificant. Since the total content of flavonoids and anthocyanins in all organs of the above‐ground part of natural samples of milk thistle was studied for the first time, the results obtained will be interesting in terms of the complex use of raw materials. The results of assessment of the variability of the content of phenolic compounds in samples depending on the complex of factors of the altitude gradient in the natural conditions of Dagestan provide information for clarifying the mechanisms of accumulation of secondary metabolites.