Sergey V Popov

Komi Scientific Center · molecular immunology and biotechnology

This study aims to develop hydrogels from apple pectin (AP) and hogweed pectin (HP) in multiple ratios (4:0; 3:1; 2:2; 1:3; and 0:4) using ionotropic gelling with calcium gluconate. Rheological and textural analyses, electromyography, a sensory analysis, and the digestibility of the hydrogels were determined. Increasing the HP content in the mixed...

The study aims to investigate the adhesion of a hydrogel made of cross-linked low-methyl esterified pectin to rat intestinal serosa ex vivo. The adhesivity of the FeP hydrogel, which was cross-linked by Fe3+ cations, exceeded that of hydrogels cross-linked by Ca2+, Zn2+, and Al3+ cations. The concentration of the cross-linking cation failed to infl...

The aim of the study is to develop and evaluate the printability of k-carrageenan inks enriched with callus tissue of lupin (L. angustifolius) and to determine the effect of two lupin calluses (LA14 and LA16) on the texture and digestibility of 3D-printed gel. The results demonstrated that the enriched ink was successfully 3D printed at concentrati...

Stress effects activate the processes of free radical oxidation in the organism, lead to hyper production of reactive radicals and oxidative stress, provoking the development of an inflammatory process in various parts of the gastrointestinal tract. Pectin polysaccharides together with the enzyme components of the endogenous antioxidant system cont...

The study aimed to compare the in vitro biocompatibility of pectin gels formed by different cross-linking cations. Hydrogel beads named CaPG, ZnPG, FePG, and AlPG were prepared from 4% solutions of apple pectin using ionotropic gelling with CaCl2, ZnCl2, FeCl3, and AlCl3, respectively. Cations influenced the gel strength of the wet gel beads in the...

The aims of the study were to evaluate the influence of pectin isolated from fireweed (FP) on the mechanical and rheological properties of agar (A) gel, to investigate the release of phenolic compounds (PCs) and pectin from A-FP gels at simulated digestion in vitro, and to evaluate the oral processing and sensory properties of A-FP gels. The hardne...

The above-ground part of the Salsola passerine was found to contain ~13% (w/w) of polysaccharides extractable with water and aqueous solutions of ammonium oxalate and sodium carbonate. The fractions extracted with aqueous sodium carbonate solutions had the highest yield. The polysaccharides of majority fractions are characterized by similar monosac...

Introduction COVID19 lockdown is having a significant impact on mental health, patients with eating disorders (ED) are particularly vulnerable. Objectives 1) To explore changes in eating and other psychological features due to confinement in patients with ED from various European and Asian countries; and 2) to assess differences related to diagnos...

There are numerous studies which show that an early school start time has a negative impact on the sleep, well-being, and academic performance of students. There is not enough information on the association between school start time and eating disorders, however: the disruption of the circadian rhythm is known to be a risk factor for eating disorde...

Purpose The concept of time perspective (TP) implies that a mental focus on past, present, or future affect a person makes decisions and take action. Inability to plan their life for a sufficiently long time perspective due to the COVID-19 pandemic appeared to have a pronounced impact on a human’s lifestyle influencing their thoughts, feelings, and...

The study aims to develop gel beads with improved functional properties and biocompatibility from hogweed (HS) pectin. HS4 and AP4 gel beads were prepared from the HS pectin and apple pectin (AP) using gelling with calcium ions. HS4 and AP4 gel beads swelled in PBS in dependence on pH. The swelling degree of HS4 and AP4 gel beads was 191 and 136%,...

The aim of this study is to evaluate the associations among time perspective, sleep-wake rhythm characteristics, and psycho-emotional state during COVID-19 isolation. The study was carried out from April 17 to 14 June 2020and involved 844 people aged 17 to 26 years (average age: 19.4 ± 1.8 years, women: 79.4%). Each study participant filled out the...

This study aimed to investigate the influence of kappa (κ)-carrageenan on the initial stages of the foreign body response against pectin gel. Pectin-carrageenan (P-Car) gel beads were prepared from the apple pectin and κ-carrageenan using gelling with calcium ions. The inclusion of 0.5% κ-carrageenan (Car0.5) in the 1.5 (P1.5) and 2% pectin (P2) ge...

The purpose of this study was to analyze the association between the time perspective and the psychophysiological state of the elderly during the pandemic COVID-19. 433 residents from 11 Russian cities aged 60,8±9,8 years (range - 50-94 years, women - 78,7%) took part in the study. During the online survey, each participant of the study provided pe...

Saliva plays multifunctional roles in oral cavity. Even though its importance for the maintenance of oral health has long been established, the role of saliva in food perception has attracted increasing attention in recent years. We encourage researchers to discover the peculiarity of this biological fluid and aim to combine the data concerning all...

The aim of this study was to isolate pectins with antioxidant activity from the leaves of Epilobium angustifolium L. Two pectins, EA-4.0 and EA-0.8, with galacturonic acid contents of 88 and 91% were isolated from the leaves of E. angustifolium L. by the treatment of plant raw materials with aqueous hydrochloric acid at pH 4.0 and 0.8, respectively...

One of the possible mechanisms of the anti-inflammatory action of pectins is associated with the inhibition of excessive pro-inflammatory activity of macrophages - the cells that regulate inflammation intensity and reparative regeneration. It has been found that pectins with a low degree of methyl esterification of the carboxyl groups of the galact...

s Purpose Food addiction (FA) is one of the causes of widespread obesity in modern society. It was shown that there is an age-associated increase in incidence rate of FA in adolescents/young adults. The purpose of this study was to analyze food preferences in schoolchildren and university students with FA. Methods High school and university stude...

Objective: The purpose of this study was to analyze the relationships between food addiction (FA), anthropometric characteristics, and academic performance. Design: The average age (standard deviation [SD]) of the participants was 17.5 (2.7) years (64.1% female). Each study participant indicated their sex, height, and weight, academic performance...

Purpose: This study tested two hypotheses: a) that during COVID-19 isolation the incidence rate of food addiction is increased, and b) people with present time perspective (TP) are more likely exhibited signs of food addiction (FA). Methods: The final study sample included 949 people, mean age 21.8 ± 7.8 years (range: 17-71 years, women: 78.3%). Ea...

The low methyl-esterified and acetylated xylogalacturonan (DM 20 %, DA 2 %, Mw ∼ 58 kDa) was isolated by water extraction for 4 h × 2 at 50 °C (yield 23 %) from the pulp of baobab fruit (Adansonia digitata L.). Subsequent tightening of the conditions for water extraction by mean increasing the temperature to 70 °C and time to 12 h led to the co-ext...

Binge eating is repeated episodes of eating large amounts of sweet and fatty food in short periods. Dietary fibers, including pectin, significantly reduce the subjective ratings of hunger, and the amount of food eaten. However, studies showing the effect of dietary fibers on satiety use juices or yoghurts with added dietary fiber, or a kissel-like...

Confinement during the COVID-19 pandemic is expected to have a serious and complex impact on the mental health of patients with an eating disorder (ED) and of patients with obesity. The present manuscript has the following aims: (1) to analyse the psychometric properties of the COVID Isolation Eating Scale (CIES), (2) to explore changes that occurr...

Food addiction in young adult residents of Russia: Associations with emotional and anthropometric characteristics • March 2020 • European Eating Disorders Review • DOI: 10.1002/erv.2731 Supporting information

The incidence of food addiction (FA) and associations between FA and anthropometric and psycho‐emotional characteristics of young Russian adults were studied. In this study, 1,237 students (age, M = 20.6, SD = 4.6 years; 79% females) of universities located in four cities of Russia were attended. They provided demographics and filled in the Yale Fo...

The purpose of this investigation was to study the sleep‐wake rhythm characteristics of young persons with food addiction (FA) and symptoms of depression. A total of 2,360 young persons living in northern European Russia were included in the study. The average age of the respondents (± standard deviation [SD]) was 17.9 [4.6] years (66.6% female). E...

Low methyl-esterified pectin (AU701) was found to form gel beads with glycerol. Wet AU701-glycerol gel beads exhibited similar diameter and hardness compared to the AU701-Ca gel beads, prepared by ionotropic gelation with Ca²⁺ and used for comparison. The morphology of dry pectin gel beads determined by scanning electron microscopy revealed that th...

A diet rich in non-digestible plant polysaccharides (dietary fibers) leads to effective appetite suppression and reduces food intake. The mechanical properties of food contribute to the satiating effect of food. It is known that solid food satiates to a greater extent than liquid, as the duration of food processing in the oral cavity increases. The...

The formation of cross-related pectin matrices on the base of physiologically active polysaccharides opens up new prospects for their application in medicine. The purpose of the study was to identify pectin gels that could retain the drag in an artificial gastric environment and did not have a cytotoxic effect. Here, pectins of apple, hogweed, this...

The phase of entrainment (chronotype) is known to be associated with time perspective (TP), suggesting that the state of circadian system is involved in the long-term planning of human life. However, little is known regarding the influence of circadian misalignment on long-term planning ability. The aim of this study was to investigate the associat...

The purpose of this investigation was to study the sleep-wake rhythm characteristics of young persons with food addiction. A total of 2722 young persons living in four settlements located at latitudes between 57 and 62 degrees North were included in the study. The average age of the respondents 17.9±4.6 years (66.6% female). Each participant provid...

We studied the influence of the mechanical properties of pectin hydrogels on acute inflammation and tissue repair after subcutaneous implantation. We used hard and soft pectin hydrogels. The results of histology and the analysis of serum‐level cytokines demonstrated that the intensity of acute inflammation increased with increasing hardness of the...

The pectins were isolated from sterile stems of E. arvense (EA, yield 5.9%) and E. sylvaticum (ES, yield 4.8%) (Equisetaceae) using ammonium oxalate extraction after preliminary treatment with dilute HCl (рH 4.0). The pectins possessed high molecular weight (Mw, 340–360 kDa), high GalA content (ca. 85%), low degrees of methyl-esterification (14–16%...

Gel microparticles were prepared from pectins of campion (SVCgel) and duckweed (LMCgel) callus cultures, as well as from commercial apple pectin (APgel) by emulsion dehydration techniques with successive ionotropic gelation. The morphology and swelling behavior of the microparticles were determined after successive incubation in simulated gastric (...

The rheological characteristics and transit time of gastric digesta and the postprandial glycaemic response in mice orally administered with water (control) or pectin solutions supplemented (AP-Ca) or not supplemented (AP) with CaCO3 were elucidated. AP and AP-Ca increased viscosity, storage and loss moduluses (G’ and G’’) of mice gastric digesta....

Rheological properties of pectins with a different chemical characteristic in a simulated gastrointestinal fluid, as well as behavioural satiety sequence and food intake in mice, were investigated. Mice treated with pectin isolated from floscules of tansy Tanacetum vulgare L. (TVF) spent less time feeding and ate less food. Apple pectin (AU701) fai...

The aim of this work is to produce calcium pectin-silica gel beads containing mesalazine as a drug model in order to control the drug release in the colon. The mesalazine loaded calcium pectin-silica gel beads were prepared using the ionotropic gelation method. Energy-dispersive X-ray analysis revealed that increasing the Na2SiO3 concentration led...

People obtain pectins from plant foods. It has been shown that pectins change the concentration of cytokines. Numerous studies have demonstrated the influence of the immune system on the brain. Thus, we examined the effects of pectins on recognition memory, depression-like behaviour, spontaneous activity, the TNF-α, IL-1β, IL-6, and IFN-γ concentra...

Differences in the size, shape, and surface relief of composite gel particles prepared using pectins from Silene vulgaris (SVCI), Tanacetum vulgare (TVB), and Lemna minor (LML) and chitosan were found using scanning electron microscopy. The adhesive properties of the composite gels depended on the pectin structural features, molecular mass (Mw) and...

We studied the effect of pectin gel particles on endotoxemia in mice induced by restraint stress. It was shown that the concentration of LPS in mouse blood increased during restraint stress, which was associated with memory impairment. Pectin gel particles prevented the development of stress-induced endotoxemia and memory impairment in mice.

The antioxidant properties of vegetable pectin fractions against intraluminal reactive oxygen species were elucidated in vitro in conjunction with their structural features. The pectin fractions were isolated using a simulated gastric fluid (pH 1.5, pepsin 0.5 g/L, 37°C, 4 h) from fresh white cabbage, carrot, onion, and sweet pepper. The fraction f...

The surface structure, biocompatibility, textural and adhesive properties of calcium hydrogels derived from 1, 2 and 4% solutions of apple pectin were examined in this study. An increase in the pectin concentration in hydrogels was shown to improve their stability toward elastic and plastic deformation. The elasticity of pectin hydrogels, measured...

Young residents of the European North of Russia with normal body weight (n = 66) were divided into three groups, SJL ≤ 1 h, 1 < SJL ≤ 2 h, and SJL > 2 h, using the Munich ChronoType Questionnaire. Participants consumed a breakfast consisting of pizza ad libitum and rated their appetite sensations using visual analog scales. Participants in three SJ...

The main complication that may arise after surgery is the formation of adhesions. The current trend in the prevention of postoperative adhesions is the application of anti-adhesive barrier materials for the separation of wound tissue during the critical period of mesothelial repair and healing. In this work, cryogels based on pectin and chitosan we...

Pectin hydrogel particles (PHPs) were prepared by ionotropic gelation of low methylesterified pectin of Tanacetum vulgare L. with calcium ions. Wet PHPs prepared from TVF exhibited a smaller diameter and the lower weight as well as exhibited the best textural properties in terms of hardness and elasticity compared to the PHPs prepared from commerci...

Today, there is a need for the development of biomaterials with novel properties for biomedical purposes. The biocompatibility of materials is a key factor in determining its possible use in biomedicine. In this study, composite cryogels were obtained based on pectin and chitosan using ionic cryotropic gelation. For cryogel preparation, apple pecti...

A low-molecular derivative of the polysaccharide (5 kDa) was obtained and its cytokine-inducing and anti-inflammatory activity was studied by free radical depolymerization of chitosan (110 kDa). It was shown that high-molecular chitosan in vitro inhibited the synthesis of anti-inflammatory cytokine, the tumor necrosis factor alpha induced by endoto...

The discrepancy between biological and social rhythms known as social jetlag (SJL) is common in modern society and has a range of negative consequences for cognitive functioning, well-being and health. Social jetlag is typical for people with late chronotypes. As shown earlier, the prevalence of individuals with a late chronotype is higher among th...

An injectable hydrogel was obtained from the high methyl-esterified plum Prunus domestica L. (PD) pectin and calcium ions (Ca2+). PD hydrogel showed a weak gel-like behavior and could be squeezed out of the syringe with an injection force of ca. 9 N. PD hydrogel was not suitable for the NIH/3T3 fibroblast cell adhesion in vitro. The live/dead fluor...

The objective of this study was to generate supramolecular complexes of pectin and lignin with properties necessary to interrupt the enterohepatic circulation (EHC) of estrogens. Three types of pectin hydrogel particles were prepared from citrus pectin (PHP), citrus pectin/wheat lignin (PLWHP) or citrus pectin/oak lignin (PLOHP). The surface of PHP...

Structural peculiarities of low molecular weight (LMW) sample obtained by mild acid hydrolysis of κ-carrageenan from Chondrus armatus was investigated by a rapid mass spectrometric method. The selected conditions allowed avoiding excess destruction of 3,6-AnGal residues that was shown by using tandem (MS/MS) mode. Main oligosaccharide fraction with...

The aim of this research is to investigate the swelling properties and morphology of the calcium pectinate gel (CaPG) beads made from pectins of campion callus cultured using various medium nutrients (carbon sources, concentration of sucrose, calcium and 2,4-dichlorophenoxyacetic acid (2,4-D)). Gelled spheres were prepared by ionotropic gelation. T...

The composition of diet is one of the major determining factors for lifespan. The dietary pectins are known to have anti-inflammatory properties and may influence aging and longevity. Here we demonstrate the lifespan-extending effect of the low methyl esterified (LM) commercial pectins CU701 and AU701 in wild-type strain of Drosophila melanogaster....

Pectins are the major component of plant cell walls, and they display diverse biological activities including immunomodulation. The pectin macromolecule contains fragments of linear and branched regions of polysaccharides such as homogalacturonan, rhamnogalacturonan-I, xylogalacturonan, and apiogalacturonan. These structural features determine the...

The anti-inflammatory activity of the citrus pectins, CU701 and CU201, with low and high degrees of methylesterification (LM and HM), respectively, was studied after oral administration in mice using three models of inflammation: acetic acid-induced colitis, cytokine production by blood leukocytes in response to lipopolysaccharide (LPS) and endotox...

We previously demonstrated that pectin-protein complex (PPC) isolated from white cabbage adsorb the β-glucuronidase (βG) enzyme of E. coli. Concurrently, we discovered a significant increase in βG activity in the presence of PPC. The aim of this study is to identify the structural components of PPC that are responsible for βG adsorption and activat...

Water-soluble polysaccharide fractions VO1–VO4 were isolated from the squeezed berries of the snowball tree (Viburnum opulus) by successive extraction with water at various temperatures and pH and with aqueous solutions of ammonium oxalate. These fractions were purified by ion-exchange chromatography on DEAE cellulose, and the homogeneity of the pu...

A pectic polysaccharide, lemnan, was isolated from freshly collected duckweedLemna minor L. Its sugar chain was shown to be mainly composed of the residues ofD-galacturonic acid (64%), galactose, arabinose, xylose, andD-apiose, a branched chain sugar. The high content ofD-apiose (25%) indicated that lemnan is an apiogalacturonan type pectin similar...

A pectic polysaccharide named capsicuman (CA) was isolated from fresh sweet pepper by extraction with a saline solution containing hydrochloric acid (pH 1.5) and pepsin at 37°C for 4h. Capsicuman was shown to consist of d-galacturonic acid (GalA, 74.0%), rhamnose (Rha, 1.6%), arabinose (Ara, 2.6%) and galactose (Gal, 2.4%) residues. This polysaccha...

It has been shown that pectin polysaccharides from different plants, depending on their structure, can either protect the intestinal walls of mammals against damage and inhibit the development of inflammation or, on the contrary, have proinflammatory effects. At the same time, galacturonan isolated from any pectin, being the main carbohydrate chain...

A pectic polysaccharide called apiuman was isolated from fresh celery stalks by extraction with an aqueous ammonium oxalate followed by ultrafiltration, and was shown to consist of d-galacturonic acid (GalA, 81.0%), l-rhamnose (Rha, 2.6%), l-arabinose (Ara, 2.5%), and d-galactose (Gal, 3.6%) residues. Apiuman was found to be digestible with α-1,4-d...

We studied the effects of dietary pectins (citrus pectin [CP] and apple pectin) on oral tolerance in mice. Pectins (1 mg/d) were administered orally for 2 wk. Tolerance was induced with 20 mg of ovalbumin (OVA). Levels of serum antibodies (immunoglobulin [Ig] G, IgG1, IgG2a, IgE) and delayed type hypersensitivity response determined in footpad test...

The pectic polysaccharide named rauvolfian RS was obtained from the dried callus of Rauvolfia serpentina L. by extraction with 0.7% aqueous ammonium oxalate. Crude rauvolfian RS was purified using membrane ultrafiltration to yield the purified rauvolfian RSP in addition to glucan as admixture from the callus, with molecular weights 300 and 100-300...

The pectic polysaccharide named potamogetonan (PN) was obtained using extraction of the leaves and stems of the common pondweed Potamogeton natans L. by an aqueous ammonium oxalate. The purified potamogetonan PN-300 was obtained using membrane ultrafiltration of PN and proved to be pectin with a molecular weight of 300 kDa. The capacity of potamoge...

The inhibition of the adhesion of neutrophils to fibronectin by the fragments of the main galacturonan chain of the following pectins was demonstrated: comaruman from the marsh cinquefoil Comarum polustre, bergenan from the Siberian tea Bergenia crassifolia, lemnan from the duckweed Lemna minor, zosteran from the seagrass Zostera marina, and citrus...

To study isolation and chemical characterization of pectin derived from the common cranberry Vaccinium oxycoccos L. (oxycoccusan OP) and the testing of its preventive effect on experimental colitis. Mice were administrated orally with OP two days prior to a rectal injection of 5% acetic acid and examined for colonic damage 24 h later. Colonic infla...

The efficacy of comaruman CP, a pectin of marsh cinquefoil Comarum palustre L., was investigated using a model of acetic acid-induced colitis in mice. Mice were administered comaruman CP orally 2 days prior to rectal injection of 5% acetic acid and examined for colonic damage 24 hr later. Colonic inflammation was characterized by macroscopical inju...

Lemnan LM, apiogalacturonanic pectin of duckweed Lemna minor L. was tested for adjuvant properties following oral administration with protein antigen. Male Swiss mice were orally immunized thrice with weekly intervals with free OVA or OVA with lemnan (LM). Lemnan LM was shown to increase delayed type hypersensitivity (DTH) and serum anti OVA IgG re...

Galacturonan, the main constituent of the backbone (core) of the comaruman macromolecule, a pectin from the marsh cinquefoil Comarum palustre L., was obtained on partial acid hydrolysis of the pectin. Using atomic force microscopy and methylation analysis of the galacturonan, the backbone of the comaruman macromolecule was shown to contain branches...

An effect of apiogalacturonanic pectin of duckweed Lemna minor L. (lemnan LM) was studied on the inflammatory response to ovalbumin injected intradermally into the footpad of control and ovalbumin-fed mice. Lemnan LM (1–2 mg per mouse) was found to enhance by as much as 50–60% the footpad swelling in control mice. Oral administration of ovalbumin w...

A pectic polysaccharide, lemnan LMC, was extracted from the callus of duckweed Lemna minor L. and was tested for adjuvant properties at oral administration with protein antigen. Mice were orally immunized thrice with weekly interval with free hen's egg lysozyme or lysozyme with LMC. Lemnan LMC was shown to increase delayed type hypersensitivity and...

The pectic polysaccharide named bergenan BC was obtained using extraction of the green leaves of Siberian tea Bergenia crassifolia (L.) Fritsch. by an aqueous ammonium oxalate. The polysaccharide obtained was proved to comprise mainly d-galacturonic acid, galactose, rhamnose, arabinose and glucose residues and appeared to be pectin. Delayed type hy...

A pectic polysaccharide named comaruman (CP) was extracted from the aerial part of Comarum palustre with 0.7% aqueous ammonium oxalate and subsequent precipitation with ethanol. Oral administration of comaruman (5-100 mg/kg) was found to reduce a paw edema observed 24 h after injection of 2% formalin in mice. A fraction of comaruman (CP-H9) exhibit...