Dioscorea deltoidea is a medicinal plant valued for its high content of steroidal glycosides (SG) – bioactive compounds with cardioprotective and immunomodulation actions, also used to treat reproductive system disorders. To overcome the limitations of natural resources of this species, a suspension cell culture of D. deltoidea was developed as a renewable and ecologically sustainable source of raw biomass and SG. Cell culture demonstrated stable and intensive growth in the laboratory (20 L) and industrial (630 L) bioreactors operated under a semi-continuous regime (specific growth rate 0.11–1.12 day−1, growth index 3.5–3.7). Maximum dry weight accumulation (8.5–8.8 g/L) and SG content (47–57 mg/g DW) were recorded during the stationary phase. Bioreactor-produced cell biomass contained inorganic macro (К, Ca, Mg, Na) and micro (Zn, Mn, Fe, B, Al, Cu, Cr, Se, Co, Ni) elements in concentrations within the safe range of dietary recommendations. Acute toxicity test showed no or insignificant changes in organ weight, hematological panel and blood biochemistry of laboratory animals fed with 2000 and 5000 mg/kg dry biomass. The results suggest that cell culture of D. deltoidea grown in bioreactors has great potential to be used as functional foods and a component of specialized dietary supplements in complex therapy of reproductive system disorders and mineral deficiency.

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In this paper we study the distance Ramsey number R D (s, t, d). The distance Ramsey number R D (s, t, d) is the minimum number n such that for any graph G on n vertices, either G contains an induced s-vertex subgraph isomorphic to a distance graph in R d or G contains an induced t-vertex subgraph isomorphic to the distance graph in R d . We obtain the upper and lower bounds on R D (s, s, d), which are similar to the bounds for the classical Ramsey number R .

Chemical diversity of secondary metabolites provides a considerable variety of pharmacological actions with a significant extension due to their combinations in plant extracts. Production of plant‐derived medicinal products in cell cultures has advantages because of the efficient use of different biotic and abiotic elicitors and better control of the developmental processes. Using PASS software, we predicted biological activity spectra for phytoconstituents identified in cell cultures of Panax japonicus (12 molecules), Tribulus terrestris (4 molecules), and Dioscorea deltoidea (3 molecules). Mechanisms of action associated with the antihypoxic effect were predicted for the majority of molecules. PharmaExpert software allowed analyzing possible synergistic or additive effects of the combinations of phytoconstituents associated with the antihypoxic action. Experimental studies of the antihypoxic effect of the plants′ extracts in water and ethanol have been performed in 3 animal models: Acute asphyctic hypoxia (AAH), Acute haemic hypoxia (AHeH), and Acute histotoxic hypoxia (AHtH). Effects of Panax japonicus and Tribulus terrestris preparations exceeded the activity of the reference drug Mexidol in the AHtH model. In the AHeH model, all preparations demonstrated moderate activity; the most potent has been observed for Dioscorea deltoidea. Thus, we found that experimental studies in animal models have confirmed the in silico prediction.

One of the main furostanol glycosides in Dioscorea deltoidea suspension cell culture, i.e., protodioscin, was isolated and characterized structurally using NMR spectroscopy, high-resolution mass spectrometry, and an analysis of its accumulation.

An important task is to monitor the physiological state of the cell population when scaling appa ratus cultivation of higher plants' cell cultures to industrial volumes. Investigations were carried out on the culture of Dioscorea deltoidea Wall-strain producer of steroidal glycosides (protodioscin and deltoside)-for which growth characteristics and content of furostanol glycosides were determined during the semirun ning growth in bubble bioreactors (20 and 630 L); total rate of oxygen uptake and the portion of participation of alternative oxidase (AO) in the process were measured in the exponential growth phase. The measurements were performed for 3-4 subculture cycles for each apparatus, starting from the second cycle from the moment of inoculation. The values of oxygen mass transfer coefficients (K La , h -1 ) for bioreactors were determined at modes of mixing and aeration optimal for growing strain. The maximal portion of cyanide resistant respira tion was determined in 20 liter bubble bioreactor with a point aerating device (up to 60-65% of total respi ration rate). The minimal values of (K La (2.0-2.4 h -1 ) were obtained for the same apparatus, as well as lower levels of furostanol glycosides (4.2-8.0% of dry cell weight). Apparently, this effect was due to insufficiently uniform distribution of oxygen in the nutrient medium. Minimal activity of AO (within 15-25%) was noted for the system with more intensive mass transfer of oxygen-in 630 liter bubble bioreactor with the annular aerator (K La 7.1-8.0 h -1 ). Higher biosynthetic rates (7.7-13.9% of dry cell weight) were found in the same bioreactor.

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