Optimization of flavonoid extraction conditions from the leaves and stems of medicinal rosemary (Rosmarinus officinalis L.)

Introduction. Rosemary (Rosmarinus officinalis L.) is of significant interest as a source of biologically active compounds, particularly flavonoids and phenolic acids, which possess a pronounced hepatoprotective potential. The pharmaceutical markets of the Republic of Algeria and the Russian Federation have a need for affordable hepatoprotective agents based on herbal raw materials, which determines the relevance of developing domestic herbal preparations.

Objective: to optimize the conditions for the extraction of flavonoid compounds from the leaves and stems of rosemary officinalis for the development of a phytopreparation intended for the prevention and treatment of liver diseases.

Materials and methods. The object of the study was leaves and stems of medicinal rosemary (Rosmarinus officinalis L.), which are part of the shoots. The raw material was provided by the Algerian company “Tazmert” (batch No.ROS-2024-03, expiration date until 03.2026, moisture content 10%). The study investigated the influence of key technological parameters on the extraction process of flavonoids. For the quantitative determination of the total flavonoid content, a differential spectrophotometry method based on the reaction with aluminum chloride was used; measurements were taken at a wavelength of 400 nm with recalculation based on cynaroside.

Results. It was found that the maximum yield of flavonoids (1.76±0.06% in terms of cynaroside) is achieved under the following optimal conditions: a grinding degree of 1-2 mm, 75% ethyl alcohol, a plant material:extractant ratio of 1:100, and an extraction time of 45 minutes. The metrological evaluation confirmed the high reproducibility of the method (RSD did not exceed 2.66%, relative error was 3.3%).

Conclusion. The established optimal extraction conditions enable a yield of total flavonoids of 1.76 ± 0.06% (in terms of cynaroside), which opens prospects for the development of a new effective herbal medicine with hepatoprotective properties. The obtained results create a scientific basis for standardization of rosemary extract production technology and development of domestic medicinal products.