Abstract
This study presents a phytochemical and elemental characterization of Rheum tataricum L. collected in the Almaty region of Kazakhstan, aimed at describing its compositional features as a potential source of plant secondary metabolites. Elemental analysis revealed high levels of calcium, magnesium, phosphorus, sulfur, and zinc in the leaves, whereas the stems contained elevated levels of rubidium and comparable amounts of potassium, sodium, and chlorine. Quantitative phytochemical screening demonstrated a generally stable accumulation of major metabolite groups, including anthraquinones, flavonoids, tannins, triterpenoids, and phenolic acids, across vegetative stages, with noticeable seasonal variation observed primarily for carbohydrates and tannins. The stems were characterized by higher contents of tannins and triterpenoids, whereas the leaves accumulated greater amounts of phenolic acids and micronutrients. These organ-specific and stage-dependent patterns reflect ecological adaptation to semi-desert conditions and suggest complex regulation of secondary metabolism in R. tataricum. The results highlight the phytochemical richness of this species; however, its bio-logical and pharmacological activities cannot be inferred from the present data and require confirmation through dedicated bioassays.