Plantago asiatica L. — эндемичный вид наземного растения, произрастающего на территории Восточной Сибири и Дальнего Востока России, также встречается в восточноазиатских странах, не является фармакопейным видом. В данной работе проведен сравнительный фитохимический и фармакогностический анализ листьев Plantago asiatica L. и Plantago major L. Из листьев обоих видов подорожника выделены пектины, определено их содержание в сырье (12,80 ± 0,56 % в листьях Plantago asiatica L. и 5,58 ± 0,25 % в листьях Plantago major L.), а также основные физико-химические характеристики (молекулярно-массовое распределение, содержание ангидрогалактуроновой кислоты, степень метоксилирования).

Plantago asiatica L. is an endemic terrestrial plant species which grows in Eastern Siberia and the Russian Far East, and is also found in East Asian countries; it is not a pharmacopeia species.We report here a comparative phytochemical and pharmacognostic analysis of the leaves of Plantago asiatica L. and Plantago major L. Pectins were isolated from the leaves of both plantain species and their contents in raw materials were determined (12.80 ± 0.56

Poorly esterified pectin was isolated from the seagrass Phyllospadix iwatensis Makino, 1931 and modified using acidic hydrolysis in 0.5 M HCl. The concentration of anhydrogalacturonic acid, the degree of methoxylation, and the molecular weight distribution were determined in the native and hydrolyzed pectins. The sorption capacity of these pectins with regard to strontium and yttrium ions was evaluated at pH 6.0. It was found that the molecular weight of the native pectin decreased by 2.9 times during hydrolysis; the relative content of anhydrogalacturonic acid in the native pectin increased by 14%, while the degree of esterification decreased from 5.22 to 0%. The sorption capacity of the hydrolyzed pectin increased for strontium and yttrium ions by 40 and 48%, respectively. In our study, hydrolyzed pectin fully retained the ability to bind metal ions from their solutions at a low concentration.

Nowadays, heavy metal contamination of environment is considered as a serious threat to public health because of toxicity of these pollutants and the lack of effective materials with metal-binding properties. Some biopolymers such as pectins were proposed for removal of metal ions from industrial water disposals. Chemical structure of pectins is quite variable and substantially affects their metal binding properties. In this work, relationship between molecular weight and Pb(II)-binding capacity of calcium pectates was investigated in a batch sorption system. The results showed that all pectate samples are able to form complexes with Pb(II) ions. The effects of contact time, pH of the media and equilibrium metal concentration on metal-binding process were tested in experiments. The equilibrium time min required for uptake of Pb(II) by pectate compounds was found to be 60 min. Langmuir and Freundlich models were applied for description of interactions between pectates and metal ions. Binding capacity of low molecular pectate was highest among all the samples tested. Langmuir model was figured out to be the best fit within the whole range of pH values. These results demonstrate that calcium pectate with low molecular weight is more promising agent for elimination of Pb(II) ions from contaminated wastewaters.

Pectins from sea grasses are considered as promising substances with pronounced metal-binding activity. Due to the high molecular weight and heterogeneous structure, the use of pectins for removal of metal ions is difficult. Technology of directed pectin degradation was developed and homogenous degraded nanoscaled pectin polymers were synthesized. Experimental samples of degraded pectin isolated from Phyllospadix iwatensis were tested for their metal binding activity in comparison with native pectin from this seagrass and commercial citrus pectin. The metal uptake of all pectin compounds was highest within the pH range from 4.0 to 6.0. The Langmuir, Freundlich and BET sorption models were applied to describe the isotherms and constants. Results showed that depolymerized pectin exerts highest lead and cadmium binding activity with pronounced affinity. All pectin compounds were suggested to be favorable sorbents. Therefore, it can be concluded that degraded pectin is a prospective material for creation of metal-removing water treatment systems.

Low esterified pectin was isolated from the seagrass Zostera marina . Dynamics of the isolation process for the pectin from this seagrass was investigated. Two pectin derivatives: galacturonide (A) with molecular weight 30.55 kDa and galacturonide (B) with molecular weight 3.94 kDa were obtained using acidic hydrolysis of the native pectin from Zostera marina . Molecular weight parameters (Mw, Mn, Mw/Mn) of this pectin and its derivatives as well as of commercial apple pectin were determined using gel-filtration chromatography method. Comparative assessment of Cd 2+ , Pb 2+ , Y 3+ -binding activity of the native Zostera pectin, galacturonides A and B, and commercial apple pectin was performed. The results showed that galacturonide A with molecular weight 30.55 kDa possesses highest metal-binding capacity and may be considered as a candidate for development of medicines with metal-binding activity.

The presence of radioactive substances in wastewaters poses a problem for public health due to the lack of the radioisotope-binding materials. In the present study, the yttrium-binding activity of sodium and calcium salts of alginic acid was investigated in a batch sorption system. The results showed that both polymers are able to form complexes with yttrium ions. The effects of contact time, initial concentration of the metal and pH of the media on the yttrium-binding processes were experimentally investigated. The equilibrium time was found to be at least 60 min required for adsorption of yttrium by alginate compounds regardless of the initial metal concentrations. Langmuir and Freundlich sorption models were applied for description of the binding processes. The results showed that the Langmuir model is best fit within the whole range of pH values used in the studies. The maximum adsorption capacity of calcium and sodium alginates was found to be 99.01 and 181.81 mg/g, respectively, at pH 6.0. Kinetic studies showed that reactions between alginate compounds and yttrium are corresponding to the pseudo-second-order model. These results obviously show that alginate salts may be successfully used as materials for elimination of radioisotopes from water disposals.

Carrageenans the natural polysaccharides received from red seaweed. One of their major biological properties is ability to connect ions of metals. This property allows to consider carrageenans as a basis for development drugs with radioprotective effect. Metals connecting activity of various types of carrageenans was studied in the systems containing ions of strontium or cerium. By results of experiment it is established that k-and i-carrageenans effectively connect ions of strontium and cerium, thus the greatest activity was observed at i-carrageenan.

DEvELOPMENt OF A MEthOD OF stANDARDIzAtION FOR LOw-MOLECULAR PECtINs E.V. Khozhaenko1, 2, R.Yu. Khotimchenko1, 2, V.V. Kovalev1, E.A. Podkorytova1, M.Yu. Khotimchenko1, 2 1 Institute of Marine Biology named after A.V. Zhirmunskiy Far Eastern Branch of RAS (17 Palchevskogo St. Vladivostok 690041 Russian Federation), 2 School of Biomedicine of Far Eastern Federal University (8 Sukhanova St. Vladivostok 690950 Russian Federation) background. Object of this study was developing a method of stan‐ dardization of low‐molecular pectins‐oligouronids according to the chain‐length distribution for subsequent validation. Methods. Standardization of oligouronids was carried out using ex‐ clusion chromatography techniques and analysis of reducing end groups. The authors studied the eluent influence on the separation of oligouronids with molecular weights of 2.8–15.5 kDa on column with hydrophilic sorbent Shodex Asahipak GS‐320 7E. Results. It has been established that the optimal separation of oli‐ gouronids on molecular weight is achieved in 0.1M of sodium ni‐ trate at 35 °C and the eluent speed of 0.8 ml/min. The values of mass average and number average for oligouronids molecular weights obtained respectively with the exclusion chromatography methods and analysis of the end groups were similar that indicates a rela‐ tively small value of polydisperse samples and the validity of these methods for standardizing oligouronids. Conclusions. When comparing the modified tetrazolium method and Nelson method for analyzing oligouronids end groups it was determined that Nelson method allows to obtain more accurate and reliable results and it is applicable for oligouronids standard‐ ization.

Подкорытова Елена Алексеевна – канд. биол. наук, научный сотруд‐ ник лаборатории фармакологии Института биологии моря ДВО РАН; e‐mail: eapodkorytova@mail.ru DEvELOPMENt OF tEChNOLOgy FOR qUICk-DIssOLvINg FORM OF sODIUM ALgINAtE V.V. Kovalev1, R.Yu. Khotimchenko1, 2, E.A. Podkorytova1, E.V. Khozhaenko1, 2 1 Institute of Marine Biology named after A.V. Zhirmunskiy FEB RAS (17 Palchevskogo St. Vladivostok 690041 Russian Federation), 2 School of Biomedicine of Far Eastern Federal University, (8 Sukhanova St. Vladivostok 690950 Russian Federation) background. Brown algae polysaccharides – are the alginates widely used in food and pharmaceutical industries as health promoting medicines in case of poisoning with heavy metals salts and radio‐ nuclides. A significant shortcoming of the alginates is their poor solubility. The purpose of research is development of a method en‐ hancing the sodium alginate solubility based on a transferring the part of uronic acids residues in the alginate molecule to the calcium salts form. Methods.The article covers the influence of calcium content on the alginate solubility. The researchers formed sorption isotherm of cal‐ cium ions by sodium alginate in the environment of 50 % ethanol and obtained the alginate samples containing from 0.2 to 6.82 % of calcium. Also they studied the hydrogels properties of the obtained samples of calcium alginate. Results. It was found that in the case of calcium content in the alginate less than 4.44 % a partial dissolution of the alginate gel starts, while calcium content less than 0.8 % promotes a complete dissolution. There have been also an estimation of dissolution rate for various alginate samples. Calcium alginate samples containing 0.2‐0.8 % of calcium showed a higher rate of dissolution by 6.2‐13.4 times than the original sodium alginate. Conclusions. Technology for producing incomplete calcium salts of alginates may be a new and very efficient approach to the prob‐ lem of their solubility and, therefore, improvement of consumer properties.

Brown algae polysaccharides are the alginates widely used in food and pharmaceutical industries as health promoting medicines in case of poisoning with heavy metals salts and radionuclides. A significant shortcoming of the alginates is their poor solubility. The purpose of research is development of a method enhancing the sodium alginate solubility based on a transferring the part of uronic acids residues in the alginate molecule to the calcium salts form. Methods. The article covers the influence of calcium content on the alginate solubility. The researchers formed sorption isotherm of calcium ions by sodium alginate in the environment of 50 % ethanol and obtained the alginate samples containing from 0.2 to 6.82 % of calcium. Also they studied the hydrogels properties of the obtained samples of calcium alginate. Results. It was found that in the case of calcium content in the alginate less than 4.44 % a partial dissolution of the alginate gel starts, while calcium content less than 0.8 % promotes a complete dissolution. There have been also an estimation of dissolution rate for various alginate samples. Calcium alginate samples containing 0.2-0.8 % of calcium showed a higher rate of dissolution by 6.2-13.4 times than the original sodium alginate. Conclusions. Technology for producing incomplete calcium salts of alginates may be a new and very efficient approach to the problem of their solubility and, therefore, improvement of consumer properties.

The paper describes kinetics of binding of lead ions with low-etherized pectins with different molecular masses determined by means of acid hydrolysis. The authors have determined indices of maximum metal-binding activity of the pectin specimen under study with the environmental pH range of 2 to 6. The Langmuir adsorption model was used to describe adsorption isotherms and calculate adsorption parameters. As reported, as the molecular mass of pectins reduces, the maximum adsorption capacity reliably increases and the affinity of pectin to lead ions decreases.

By means of the modified method of acid hydrolysis from alginic acid were received oligouronides with different values of molecular masses. For definition the molecular-mass characteristics it was used high effective exclusive chromatography. The ability of the received alginates to connect ions of cadmium and lead was studied in vitro. To the description of sorption isotherms and estimation the sorption indicators it was applied Lengmuir, Friendlich's and Bryune-Emmet-Teller (BET)sorption models. It is established that middle-molecular and low-molecular alginates possess bigger sorption ability concerning cadmium and lead, than high-molecular alginate.

Exposure to strontium isotopes remains a widespread problem in most industrialized countries. Modern agents purposed for prevention of the radioisotope absorption as well as for therapy of chronic poisoning with these substances generally exert toxic effects causing mineral misbalance. Dietary non-starch polysaccharides were suggested as substances effectively binding bivalent ions. The present study was carried out to estimate strontium binding capacity of low and high esterified pectin compounds and their influence on strontium absorption, distribution, and removal in laboratory rats. Under in vitro conditions, pectin with low degree of esterification was the most effective and bound 2.2 mmol of strontium ions per gram. Administration of low esterified pectin and its calcium salt in rats resulted in significantly reduced amount of strontium accumulated in liver, heart, kidney, and femur. After advance administration of the strontium chloride solution the low esterified pectin and calcium pectate contributed to the removal of the strontium ions from organs and femur in rats. All their effects were more pronounced than those of high esterified pectin. These effects were also proved by 45.7% and 21.0% increased amount of strontium being eliminated with feces of the animals given respectively calcium pectate and low esterified pectin. The results obtained show that the low esterified pectin and calcium pectate may be considered as the perspective dietary components protecting humans from environmental strontium.

In this study, we determined the parameters of sorption of strontium ions by pectins that were isolated from the sea grasses Zostera marina and Phyllospadix iwatensis collected in the Peter the Great Bay of the Sea of Japan. The maximum strontium binding capacity and the coefficient of affinity with respect to strontium ions were significantly higher in sea grass pectins than in commercial pectin. These parameters were correlated with the etherification degree of pectins. The sea grasses studied here can be considered as a promising source of pectins for the binding and removal of strontium radioisotopes from the human body.