Abstract
<jats:p>For the great burnet (Sanguisorba officinalis L.) raw material rational harvesting, as well as ensuring its comprehensive, waste-free utilization, it is necessary to assess the influence of growing locations, age, vegetation phase, climatic, and soil conditions on the tannins accumulation in its above-ground and underground organs. The research was conducted during the period 2018–2020. Raw material harvesting was carried out in three natural cenopopulations (CP): CP I – floodplain grass-herbaceous meadow, CP II – dryland herbaceous meadow, CP III – birch forest, during different vegetation periods. The tannin content in the raw material was determined by permanganatometric titration in accordance with the requirements of the XV edition State Pharmacopoeia. It was found that in the herb maximum tannins amount accumulates during the flowering phase (6.096–9.323 %) and the minimum during the fruiting period (4.049–7.998 %). Rhizomes and roots are characterized by the presence of two accumulation maxima: at the beginning of vegetation (19.194–24.698 %) and during the flowering period (21.310–26.595 %). The tannin content in the fruiting phase decreases in underground organs by an average of 1.3 times, and in the above-ground organs – by 1.2 times. The studies showed that the moisture level and light availability, soil factors (high content of humus, phosphorus, potassium) contribute to greater tannin accumulation. Its highest content was observed in the above-ground and underground organs of burnet in CP I and CP II. The calculated extremality hydrothermal coefficient (Kextr.) ranged from 0.22 to 0.26 in the study years. The highest Kextr. was obtained for 2019 (0.26), which showed the lowest tannin content. The tannin accumulation patterns obtained data in the great burnet above-ground and underground organs have a practical importance for the pharmaceutical industry.</jats:p>