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Daniil N. Olennikov

Bio: Daniil N. Olennikov is an academic researcher from Russian Academy of Sciences. The author has contributed to research in topics: Chemistry & DPPH. The author has an hindex of 22, co-authored 176 publications receiving 1412 citations. Previous affiliations of Daniil N. Olennikov include North-Eastern Federal University.


Papers
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TL;DR: The results obtained in this study reveal that Siberian Artemisia species and CQAs possess a pronounced inhibitory activity against α-amylase and α-glucosidase and could become a complement to synthetic antidiabetic drugs for controlling blood glucose level.
Abstract: Artemisia genus of Asteraceae family is a source of medicinal plants known worldwide and used as ethnopharmacological remedies for the treatment of diabetes in Northern Asia (Siberia) The aim of this study was to determine the phenolic profile of 12 Siberian Artemisia species (A anethifolia, A commutata, A desertorum, A integrifolia, A latifolia, A leucophylla, A macrocephala, A messerschmidtiana, A palustris, A sericea, A tanacetifolia, A umbrosa) and to test the efficacy of plant extracts and pure compounds for antidiabetic potential Finally, by HPLC-DAD-ESI-TQ-MS/MS technique, 112 individual phenolic compounds were detected in Artemisia extracts in a wide range of concentrations Some species accumulated rare plant phenolics, such as coumarin-hemiterpene ethers (lacarol derivatives) from A latifolia and A tanacetifolia; melilotoside from A tanacetifolia; dihydrochalcones (davidigenin analogs) from A palustris; chrysoeriol glucosides from A anethifolia, A sericea, and A umbrosa; eriodictyol glycosides from A messerschmidtiana; and some uncommon flavones and flavonols The predominant phenolic group from Artemisia species herb was caffeoylquinic acid (CQAs), and in all species, the major CQAs were 5-O-CQA (2028-12799 μg/g) and 3,5-di-O-CQA (735-24361 μg/g) In a series of in vitro bioassays, all studied Artemisia extracts showed inhibitory activity against principal enzymes of carbohydrate metabolism, such as α-amylase (IC50 = 15024-38414 μg/mL) and α-glucosidase (IC50 = 21442-75412 μg/mL) Although many phenolic compounds can be inhibitors, experimental evidence suggests that the CQAs were key to the biological response of Artemisia extracts Mono-, di- and tri-substituted CQAs were assayed and showed inhibition of α-amylase and α-glucosidase, with IC50 values of 4057-17247 μM and 6108-124035 μM, respectively, and they were more effective than acarbose, a well-known enzyme inhibitor The results obtained in this study reveal that Siberian Artemisia species and CQAs possess a pronounced inhibitory activity against α-amylase and α-glucosidase and could become a complement to synthetic antidiabetic drugs for controlling blood glucose level

90 citations

Journal ArticleDOI
TL;DR: It was found that antioxidant activity of preparations obtained from L. sulphureus is conditioned by phenolic compounds, and these compounds were extracted for the first time.
Abstract: Antioxidant activity of fruit bodies of Laetiporus sulphureus (Bull.: Fr.) Murr. (Polyporales) obtained by the natural plantation growing method in Pribaikal'e (Irkutsk region) has been studied. It was determined that the ethyl acetate fraction of L. sulphureus, which was chromatographically separated into seven compounds identified as quercetin, kaempferol, (+)-catechin, p-coumaric, gallic, caffeic, and chlorogenic acids was characterized with more expressed antioxidant activity. All compounds were extracted from this basidiomycete species for the first time. The quantitative amount of the substances isolated from L. sulphureus was determined by HPLC. It was found that antioxidant activity of preparations obtained from L. sulphureus is conditioned by phenolic compounds.

55 citations

Journal ArticleDOI
TL;DR: For the first time, it was established that the cold acclimation of D. palmatum seedlings resulted in various changes in physiological and biochemical parameters such as membrane permeability, photosynthetic potential, membrane fluidity, leaf surface secretory function, reactive oxygen species–antioxidant balance, osmoregulator content and cell wall polymers.
Abstract: The influence of climatic factors, e.g., low temperature, on the phytochemical composition and bioactivity of the arctic plant Dracocephalum palmatum Steph. ax Willd. (palmate dragonhead), a traditional food and medical herb of Northern Siberia, was investigated. D. palmatum seedlings were grown in a greenhouse experiment at normal (20 °C, NT) and low (1 °C, LT) temperature levels and five groups of components that were lipophilic and hydrophilic in nature were characterized. The analyses indicated that D. palmatum under NT demonstrates high content of photosynthetic pigments, specific fatty acid (FA) profile with domination of saturated FA (53.3%) and the essential oil with trans-pinocamphone as a main component (37.9%). Phenolic compounds were identified using a combination of high performance liquid chromatography with diode array detection and electrospray ionization mass-spectrometric detection (HPLC-DAD-ESI-MS) techniques, as well as free carbohydrates and water soluble polysaccharides. For the first time, it was established that the cold acclimation of D. palmatum seedlings resulted in various changes in physiological and biochemical parameters such as membrane permeability, photosynthetic potential, membrane fluidity, leaf surface secretory function, reactive oxygen species–antioxidant balance, osmoregulator content and cell wall polymers. In brief, results showed that the adaptive strategy of D. palmatum under LT was realized on the accumulation of membrane or surface components with more fluid properties (unsaturated FA and essential oils), antioxidants (phenolic compounds and enzymes), osmoprotectants (free sugars) and cell wall components (polysaccharides). In addition, the occurrence of unusual flavonoids including two new isomeric malonyl esters of eriodictyol-7-O-glucoside was found in LT samples. Data thus obtained allow improving our understanding of ecophysiological mechanisms of cold adaptation of arctic plants.

55 citations

Journal ArticleDOI
TL;DR: In the case of Padma Hepaten, the data obtained indicate that urolithins have the potential to play a role in the hepatic prevention against oxidative damage, and it is speculated thatUrolithin C with close values of hepatoprotection to gallic acid is the most potent compound.
Abstract: Chebulic ellagitannins (ChET) are plant-derived polyphenols containing chebulic acid subunits, possessing a wide spectrum of biological activities that might contribute to health benefits in humans. The herbal formulation Padma Hepaten containing ChETs as the main phenolics, is used as a hepatoprotective remedy. In the present study, an in vitro dynamic model simulating gastrointestinal digestion, including dialysability, was applied to estimate the bioaccessibility of the main phenolics of Padma Hepaten. Results indicated that phenolic release was mainly achieved during the gastric phase (recovery 59.38%-97.04%), with a slight further release during intestinal digestion. Dialysis experiments showed that dialysable phenolics were 64.11% and 22.93%-26.05% of their native concentrations, respectively, for gallic acid/simple gallate esters and ellagitanins/ellagic acid, in contrast to 20.67% and 28.37%-55.35% for the same groups in the non-dialyzed part of the intestinal media. Investigation of human gut microbiota metabolites of Padma Hepaten and pure ChETs (chebulinic, chebulagic acids) established the formation of bioactive urolithins (A, B, C, D, M5). The fact of urolithin formation during microbial transformation from ChETs and ChET-containing plant material was revealed for the first time. Evaluation of the protective effect of ChETs colonic metabolites and urolithins on tert-butyl hydroperoxide (t-BHP)-induced oxidative injury in cultured rat primary hepatocytes demonstrated their significant reversion of the t-BHP-induced cell cytotoxicity, malonic dialdehyde production and lactate dehydrogenase leakage. The most potent compound was urolithin C with close values of hepatoprotection to gallic acid. The data obtained indicate that in the case of Padma Hepaten, we speculate that urolithins have the potential to play a role in the hepatic prevention against oxidative damage.

54 citations

Journal ArticleDOI
TL;DR: The presented results suggest that isorhamnetin and quercetin and its glycosides can be considered as potential anti-acetylcholinesterase agents.
Abstract: Marigold (Calendula officinalis L.) is one of the most common and widespread plants used medicinally all over the world. The present study aimed to evaluate the anti-acetylcholinesterase activity of marigold flowers, detect the compounds responsible and perform chemical analysis of marigold commercial products. Analysis of 23 varieties of C. officinalis flowers introduced into Siberia allowed us to select the Greenheart Orange variety due to the superior content of flavonoids (46.87 mg/g) and the highest inhibitory activity against acetylcholinesterase (IC50 63.52 µg/mL). Flavonoids, isorhamnetin and quercetin derivatives were revealed as potential inhibitors with the application of high-performance liquid chromatography (HPLC) activity-based profiling. Investigation of the inhibitory activity of isorhamnetin glycosides demonstrated the maximal potency for isorhamnetin-3-О-(2'',6''-di-acetyl)-glucoside (IC50 51.26 μM) and minimal potency for typhaneoside (isorhamnetin-3-O-(2'',6''-di-rhamnosyl)-glucoside; IC50 94.92 µM). Among quercetin derivatives, the most active compound was quercetin-3-О-(2'',6''-di-acetyl)-glucoside (IC50 36.47 µM), and the least active component was manghaslin (quercetin-3-O-(2'',6''-di-rhamnosyl)-glucoside; IC50 94.92 µM). Some structure-activity relationships were discussed. Analysis of commercial marigold formulations revealed a reduced flavonoid content (from 7.18-19.85 mg/g) compared with introduced varieties. Liquid extract was the most enriched preparation, characterized by 3.10 mg/mL of total flavonoid content, and infusion was the least enriched formulation (0.41 mg/mL). The presented results suggest that isorhamnetin and quercetin and its glycosides can be considered as potential anti-acetylcholinesterase agents.

52 citations


Cited by
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[...]

08 Dec 2001-BMJ
TL;DR: There is, I think, something ethereal about i —the square root of minus one, which seems an odd beast at that time—an intruder hovering on the edge of reality.
Abstract: There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality. Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

33,785 citations

01 Dec 2007

1,121 citations

Journal ArticleDOI
TL;DR: The role and potential of urolithins in human health are critically reviewed, and a perspective of the research approach needed to demonstrate these health effects is presented, based on the existing knowledge.
Abstract: Urolithins are dibenzo[b,d]pyran-6-one derivatives that are produced by the human gut microbiota from ellagitannins and ellagic acid (EA). These metabolites are much better absorbed than their precursors and have been suggested to be responsible for the health effects attributed to ellagitannins and EA that occur in food products as berries and nuts. In the present review, the role and potential of urolithins in human health are critically reviewed, and a perspective of the research approach needed to demonstrate these health effects is presented, based on the existing knowledge. The analytical methods available for urolithin analysis, their occurrence in different tissues and biological fluids, and their metabolism by human gut microbiota are considered. In addition, the interindividual variability observed for the production of urolithins (metabotypes) and its relationship with health status and dysbiosis are also reviewed. The potential mechanisms of action of urolithins are also critically discussed, paying attention to the concentration and the type of metabolites used in the in vitro and in vivo assays and the physiological significance of the results obtained. The gut microbiota metabolism of EA to urolithins and that of daidzein to equol, their individual variations, and the effects on health are also compared.

303 citations

Journal ArticleDOI
TL;DR: Isoquercitrin has higher bioavailability than quercetin and displays a number of chemoprotective effects both in vitro and in vivo, against oxidative stress, cancer, cardiovascular disorders, diabetes and allergic reactions, and is a prospective substance for food supplementation.

286 citations

Journal ArticleDOI
TL;DR: Purity control of glucan fractions is necessary to evaluate the isolation and purification steps; more rigorous structural analyses of purified polysaccharides are required to clarify their structure.
Abstract: Glucans are most widespread polysaccharides in the nature. There is a large diversity in their molecular weight and configuration depending on the original source. According to the anomeric structure of glucose units it is possible to distinguish linear and branched α-, β- as well as mixed α,β-glucans with various glycoside bond positions and molecular masses. Isolation of glucans from raw sources needs removal of ballast compounds including proteins, lipids, polyphenols and other polysaccharides. Purity control of glucan fractions is necessary to evaluate the isolation and purification steps; more rigorous structural analyses of purified polysaccharides are required to clarify their structure. A set of spectroscopic, chemical and separation methods are used for this purpose. Among them, NMR spectroscopy is known as a powerful tool in structural analysis of glucans both in solution and in solid state. Along with chemolytic methods [methylation analysis (MA), periodate oxidation, partial chemical or enzymatic hydrolysis, etc.], correlation NMR experiments are able to determine the exact structure of tested polysaccharides. Vibration spectroscopic methods (FTIR, Raman) are sensitive to anomeric structure of glucans and can be used for purity control as well. Molecular weight distribution, homogeneity and branching of glucans can be estimated by size-exclusion chromatography (SEC), laser light scattering (LLS) and viscometry.

243 citations