Flavonoid Complex Research Articles

Вплив рутин-амонійного комплексу на фізіологічний стан проростків сосни звичайної

In the plant body, phenolic compounds nonspecifically affect the processes of morphogenesis and perform a wide range of regulatory and protective functions. Of particular interest are the processes involved in the complexation of flavonoids as a result of their interaction with ammonium forms of nitrogen. Polar compounds, which are formed in tissues as a result of chemical transformation, are quite mobile in soil solutions and show high biological activity. The properties of phenol-ammonium complexes are of considerable interest in terms of morphogenesis, physiology of stability, as well as in the system of interaction of plants with soil microorganisms. Studies of the effect of phenol-ammonium complex were performed on seeds and seedlings of Scots pine. Quantitative indicators of germination energy and germination were determined by seed germination. Biochemical profiling of seedling tissue extracts was performed by high-performance thin layer chromatography. It has been experimentally confirmed that rutin (quercetin-3-O-rutinoside) after interaction with 10% aqueous ammonia solution forms a complex of substances, among which the chromatography revealed polar products that potentially affect the regulation of growth. At a total concentration of 15 mg/l, these substances significantly increased germination energy and seed germination. In pine seedlings, they stimulated the growth of roots and shoots. The effect of the complex of organic compounds on seedlings depended on the concentration, duration of seed treatment and had a prolonged effect. The obtained phenol-ammonium complex at a concentration of 10-15 mg/l contributed to an increase in the amount of chlorophylls, carotenoids in the tissues of seedlings, and at 20-40 mg/l increased the content of phenolic synthesis products.

Antioxidant capacity and antimicrobial effects of zinc complexes of flavonoids – Does synergism exist?

There is a constant need for effective drugs, combinations of drugs and methods for the prevention of bacterial and viral infections, including coronavirus. It is known that the role of trace elements in strengthening the human immune system is significant. Vitamins, trace elements, including zinc, iron, selenium, magnesium and copper, and omega-3 fatty acids, play essential physiological roles in promoting the immune system. Zinc is a necessary microelement for basic enzymatic physiological processes; it plays an important role in cell division and is involved in the development of cells responsible for non-specific immunity. Zinc deficiency is known to predispose patients to viral infection due to reduced antiviral immunity. In addition, flavonoids as plant metabolites play an important role in oxidative stress prevention. This manuscript aims to discuss the roles of zinc, flavonoids and their complexes in vitro, as well as their antioxidant and antimicrobial activities. The justification for the simultaneous use of zinc and flavonoids is also considered.

Fabrication and interaction mechanism of ovalbumin‐based nanocarriers for metallic ion encapsulation

SummaryOvalbumin (OVA), due to its desirable physiochemistry properties and biocompatibility, has been widely adopted as bioactive compound carriers in the field of pharmacy and food. This study explored the interaction patterns between OVA and three flavonoids, namely naringin, hesperidin and anthocyanin, and the possibilities of OVA–flavonoid complexes as nanocarriers that entrap mineral substances. Results showed that ovalbumin interacts with three flavonoids through hydrophobic interaction and hydrogen bonding. The addition of flavonoids altered the secondary structure of OVA, decreasing the β‐sheets by 9–16% and increasing the random coils by about 20–60% for the hydroxyl groups of flavonoids coalesced with the C = O groups of amides of proteins by hydrogen bonding and hydrophobic interaction occurred from conjugation effects between aromatic rings of flavonoids and amino residues of OVA. The OVA–hesperidin complex showed comprehensive advantages over encapsulating mineral substances such as Mn, Fe, Cu and Zn.

Unravelling discolouration caused by iron-flavonoid interactions: Complexation, oxidation, and formation of networks

Iron-flavonoid interactions in iron-fortified foods lead to undesirable discolouration. This study aimed to investigate iron-mediated complexation, oxidation, and resulting discolouration of flavonoids by spectrophotometric and mass spectrometric techniques. At pH 6.5, iron complexation to the 3–4 or 4–5 site instantly resulted in bathochromic shifting of the π → π* transition bands, and complexation to the 3ʹ-4ʹ site (i.e. catechol moiety) induced a π → dπ transition band. Over time, iron-mediated oxidative degradation and coupling reactions led to the formation of hydroxybenzoic acid derivatives and dehydrodimers, respectively resulting in a decrease or increase in discolouration. Additionally, we employed XRD, SEM, and TEM to reveal the formation of insoluble black metal-phenolic networks (MPNs). This integrated study on iron-mediated complexation and oxidation of flavonoids showed that the presence of the C2–C3 double bond in combination with the catechol moiety and either the 4-carbonyl or 3-hydroxyl increased the intensity of discolouration, extent of oxidation, and formation of MPNs.

Radical Scavenging Efficiency of Flavonoids Increased by Calcium(II) Binding: Structure‐Activity Relationship

AbstractSix structurally related flavonoids including two flavones apigenin and luteolin, one isoflavone genistein, and three flavonols, galangin, kaempferol and quercetin, are affected differently as radical scavengers by presence of Ca(II). Except for apigenin showing no reaction with Ca(II), other flavonoids all coordinate with Ca(II) to form 1 : 2 Ca(II)‐flavonoid complexes confirmed by UV‐vis and mass spectra. Coordination with Ca(II) for luteolin with the 3′, 4′‐catechol group and for flavonols with 3‐hydroxyl and 4‐carbonyl significantly enhance the DPPH• scavenging efficiencies shown by stopped‐flow spectra. Addition of Ca(II) shows no effect on radical scavenging rate of Genistein, as an isomer of apigenin, although both containing the same 4‐carbonyl and 5‐hydroxyl as a potential chelating group as confirmed by mass spectra and cyclic voltammetry. The two structure elements, 3′, 4′‐catechol and the combination of 3‐hydroxyl and 4‐carbonyl, are identified as important factors for Ca(II) enhancement of radical scavenging of flavonoids. Coordination of Ca(II) to kaempferol forming a 1 : 2 Ca(II)‐kaempferol complex at 3,4 site shows the most significant enhancement in radical scavenging efficiency by a factor of 4.4 compared to other investigated flavonoids.

Vanadium-Flavonoid Complexes: A Promising Class of Molecules for Therapeutic Applications.

Several reports have revealed the superior biological activity of metal ion-flavonoid complexes when compared with the parent flavonoid. Among the different metal ions explored, vanadium and its compounds are in the forefront because of their anticancer and antidiabetic properties. However, the toxicity of vanadium-based ions and their inorganic derivatives limits their therapeutic applications. Complexation of vanadium with flavonoids not only reduces its adverse effects but also augments its biological activity. This Review discusses the nature of coordination in vanadium-flavonoid complexes, their structure-activity correlations, with special emphasis on their therapeutic activities. Several investigations suggest that the superior biological activity of vanadium complexes arise because of their ability to regulate metabolic pathways distinct from those acted upon by vanadium alone. These studies serve to decipher the underlying molecular mechanism of vanadium-flavonoid complexes that can be explored further for generating a series of novel compounds with improved pharmacological and therapeutic performance.

Redesigning Nature: Ruthenium Flavonoid Complexes with Antitumour, Antimicrobial and Cardioprotective Activities.

Flavonoids are a class of natural polyphenolic compounds sharing a common 2-phenyl-3,4-dihydro-2H-1-benzopyran (flavan) backbone. Typically known for their antioxidant activity, flavonoids are also being investigated regarding antitumour and antimicrobial properties. In this review, we report on the complexation of both natural and synthetic flavonoids with ruthenium as a strategy to modulate the biological activity. The ruthenoflavonoid complexes are divided into three subclasses, according to their most prominent bioactivity: antitumour, antimicrobial, and protection of the cardiovascular system. Whenever possible the activity of the ruthenoflavonoids is compared with that of commercial drugs for a critical assessment of the feasibility of using them in future clinical applications.

Evaluation of the Gastroprotective Effect of the Flavonoid Complex from Lychnis chalcedonica L. on the Models of Experimental Ulcerogenesis.

Using rat and mouse models of neurogenic, ethanol-induced, and indometacin-induced damage to the gastric mucosa we demonstrated that course preventive treatment with flavonoid complex from aerial parts of Lychnis chalcedonica L. increased the resistance of gastric mucosa to ulcerogenic factors of different etiology. The gastroprotective effect of the phytocomplex in a dose range of 16-1600 μg/kg was comparable with that of the reference drug plantaglucide and was superior to that of the reference drugs eleutherococcus extract and methyluracil in the therapeutic doses. The antiulcerogenic activity of Lychnis chalcedonica flavonoid complex considerably exceeded activity of Lychnis chalcedonica L. extract demonstrated in our previous experiments.

Ruthenium(II)-curcumin liposome nanoparticles: Synthesis, characterization, and their effects against cervical cancer

Ruthenium complexes have increased the scope for improvement in current cancer treatment by replacing platinum-based drugs. However, to reduce metal-associated toxicity, a biocompatible flavonoid, such as curcumin, is indispensable, as it offers uncompensated therapeutic benefits through formation of complexes. In this study, we synthesized metal-based flavonoid complexes using ruthenium(II) and curcumin by adopting a convenient reflux reaction, represented as Ru-Cur complexes. These complexes were thoroughly characterized using 1H, 13C NMR, XPS, FT-IR, and UV–vis spectroscopy. As curcumin is sparingly soluble in water and has poor chemical stability, we loaded Ru-Cur complexes into liposomes and further formed nanoparticles (NPs) using the thin layer evaporation method. These were named Ru-Cur loaded liposome nanoparticles (RCLNPs). The effects of RCLNPs on cell proliferation was investigated using human cervical cancer cell lines (HeLa). These RCLNPs exhibited significant cytotoxicity in HeLa cells. The anticancer properties of RCLNPs were studied using reactive oxygen species (ROS), LDH, and MTT assays as well as live-dead staining. Nuclear damage studies of RCLNPs were performed in HeLa cells using the Hoechst staining assay.

Influence of silymarin components on keratinocytes and 3D reconstructed epidermis

Silymarin is a flavonoid complex isolated from the plant Silybum marianum which is well known for its antioxidant, hepatoprotective and immunomodulatory effects. Since little is known about its anti-inflammatory properties and healing effects, our study focused on whether or not silymarin components reduce inflammation and support epidermis regeneration. Lipopolysaccharides (LPS) and sodium dodecyl sulfate (SDS) were used to induce inflammation in normal human epidermal keratinocytes (NHEKs) and reconstructed epidermis (RHE), respectively. The expression of pro-inflammatory cytokines (IL-1, IL-6 and IL-8) in NHEKs and RHE was measured by enzyme – linked immunosorbent assay (ELISA). The expression of cytokeratin 14 and loricrin in RHE was detected by immunofluorescent analysis. Hematoxylin and eosin staining was used for the morphological evaluation of RHE. It was determined that 2, 3 – dehydrosilybin (DHSB) downregulated the production of selected pro-inflammatory cytokines produced by NHEKs. Although all layers of RHE displayed full thickness, when SDS was applied, cell detachment was seen in the stratum corneum and loricrin expression was diminished.

Study on the structure and digestibility of high amylose Tartary buckwheat (Fagopyrum tataricum Gaertn.) starch-flavonoid prepared by different methods.

Tartary buckwheat (Fagopyrum tataricum Gaertn.) is the only food rich in flavonoid bioactive substances in grains. Studies have shown that flavonoids interaction with amylose has an important impact on the physical and chemical properties and structure of starch. In this study, Tartary buckwheat was used as a raw material. It was then threshed with pullulanase, and a high amylose Tartary buckwheat starch flavonoid complex (HBS/BF) was prepared by physical mixing (PM), water bath treatment (WT), acid-base precipitation (AP), microwave treatment (MT), and ultrasonic treatment (UT); the physical and chemical properties were then evaluated. The results show that HBS/BF-UT and HBS/BF-MT have a higher iodine binding rate than HBS/BF-PM; X-ray diffraction results show that HBS/BF-AP has a V-type crystal form, but the relative crystallinity was reduced. Fourier infrared spectroscopy showed that there is no new covalent bond between Tartary buckwheat starch and flavonoids. In vitro digestion showed that adding flavonoid significantly increased the digestibility of Tartary buckwheat starch. PRACTICAL APPLICATION: These results will provide a theoretical basis for further starch anti-digestion mechanisms and the preparation of resistant starch. These steps will provide insights into the application of Tartary buckwheat starch and flavonoids in the food industry.

Biological properties of ruthenium(II)/(III) complexes with flavonoids as ligands

• Overview of ruthenium(II)/(III) complexes with flavone derivatives. • Therapeutic properties of flavonoids and biological properties of Ru complexes with flavonoids. • Chemistry of Ru(η 6 -arene) complexes of flavonoids. • Interaction between biological targets and flavonoids and their ruthenium(II)/(III) complexes. This review highlights the progress in the development of ruthenium(II)/(III) complexes with flavone derivatives as potential therapeutic agents. We focused on natural hydroxyflavone derivatives and their synthetic amino analogues as ligands in ruthenium(II)/(III) complexes which demonstrate antimicrobial, antitumor activity and/or enzyme inhibition. Some enzymes targeted by flavone derivatives are important for the development and progression of cancer cells which underpins the design concept for the Ru complexes as multitargeted compounds consisting of a bioactive ligand and a ruthenium center.

Baking intervention for the interaction behaviours between bamboo (Phyllostachys heterocycla) leaf flavonoids and gliadin

With the growing interest in formulating nutritionally fortified baked products with added flavonoid-rich ingredients for health benefits, interactions between these ingredient classes have become critical, as they may affect product quality. In this study, the interaction behaviours that are caused by baking intervention between bamboo leaf flavonoids and gliadin were investigated. The flavonoids and gliadin were profiled via Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR) and high-performance liquid chromatography coupled with diode array detection and electrospray ionization hybrid ion trap and time-of-flight mass spectrometry (HPLC-DAD-ESI/IT-TOF-MS/MSn) to obtain molecular structural, qualitative and quantitative information. The content of flavonoids was reduced, the number of −OH groups of the flavonoids was decreased and the chemical shift of phenolic −OH was changed in the baking process. Gliadin exhibited structural changes upon sulfhydryl exposure and α-helix reduction in the baking process. Molecular docking was further performed to explore the binding mechanism in the complex of bamboo leaf flavonoids and gliadin, and the results demonstrated that hydrogen bonding and hydrophobic interaction were the main binding types. This study identified the mechanism of interaction between bamboo leaf flavonoids and gliadin in the baking process, thereby providing data support for the application of bamboo leaf flavonoids in the baking industry.

Оценка противоязвенной активности комплекса флавоноидов Lychnis chalcedonica L. на моделях экспериментального ульцерогенеза

Оценка противоязвенной активности комплекса флавоноидов Lychnis chalcedonica L. на моделях экспериментального ульцерогенеза

Study of Flavonoid/Hydroxypropyl-β-Cyclodextrin Inclusion Complexes by UV-Vis, FT-IR, DSC, and X-Ray Diffraction Analysis.

The objective of this study was to investigate characterization of inclusion complexes of flavonoids with hydroxypropyl-β-cyclodextrin (HP-β-CD). The inclusion complexes of flavonoids with HP-β-CD was prepared by the freeze-drying method and its characterization was investigated by different analytical techniques including ultraviolet-visible spectroscopy, Fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry, and X-ray diffractometry. The catechin/HP-β-CD complex exhibited the highest encapsulation efficiency (83.37%), followed by epicatechin/HP-β-CD (81.51%), morin hydrate/HP-β-CD (81.38%), and quercetin/HP-β-CD (81.16%). The inclusion complexes of HP-β-CD showed a decrease in the absorption of flavonoids with a small shift (≈2 nm) of the λmax, while similar to the characteristic absorption peak of flavonoids. However, the FT-IR spectra of the flavonoid/HP-β-CD inclusion complexes did not display any features that were like the pure flavonoids, although the spectra were very similar to that of HP-β-CD. The melting point of flavonoids disappeared, and the thermal properties of HP-β-CD were altered following formation of the inclusion complex between flavonoids and HP-β-CD, resulting in a shift in the melting peak.

Ultra-high-performance liquid chromatography - high-resolution mass spectrometry profiling and hepatoprotective activity of purified saponin and flavonoid fractions from the aerial parts of wild spinach (Chenopodium bonus-henricus L.).

An ultra-high-performance liquid chromatography- high-resolution mass spectrometry profiling method was used for a comprehensive study of flavonoid and saponin-rich fractions from the aerial parts of wild spinach (Chenopodium bonus-henricus L.). Thirty-six compounds, respectively, 22 saponins of eight sapogenins (phytolaccagenin, bayogenin, medicagenic acid, 2β-hydroxygypsogenin, 2β-hydroxyoleanoic acid, 2-hydroxy-30-nor-gypsogenin, 2-hydroxyakebonic acid, and akebonic acid) together with 12flavonoid glycosides of 6-methoxykaempferol, isorhamnetin, patuletin, spinacetin as well as two ecdysteroids (20-hydroxyecdysone and polypodine B) were detected. The occurrence of sapogenins 2-hydroxy-30-nor-gypsogenin, 2-hydroxyakebonic acid, and akebonic acid in the Chenopodium genus is reported here for the first time. The flavonoid and saponin-rich fractions showed in vitro hepatoprotective and antioxidant activity comparable to those of flavonoid complex silymarin (60μg/mL) in a model of metabolic bioactivation, induced by CCl4. All tested fractions, compared to silymarin, significantly reduced the cellular damage caused by CCl4 in rat hepatocytes, preserved cell viability and GSH level, decreased LDH leakage, and reduced lipid damage. The results showed that saponin-rich fractions F3A and F3B possessed better hepatoprotective activity than flavonoid-rich fractions (F2A and F2B). The most active was fraction F3B and this is probably due to the synergism between the saponins and some acylated flavonol glycosides found there.

System for ecological regulation of the biosynthesis of flavonoids as a strange attractor

Flavonoids are a large class of plant polyphenols with various adaptation functions to environmental factors. The biosynthesis of flavonoids is characterized by a high plasticity of their synthesis and multiple species differences. The HPLC spectra of flavonoid chromatograms from the populations of Juniperus sabina, Glycirrhiza korshinskyi, Achillea millefolia of the South Trans-Urals and pulations of Oxycoccus palustris, Chamaedaphne calyculata, Andromeda polifolia oligotrophic bogs in Western Siberia were studied. Each chromatograms of all species differed in the number of peaks, peak areas, and peak release times (compounds). It was shown that the system of flavonoid biosynthesis is fractal in nature. The species groups of flavonoids have properties of strange attractors. Using the Principal Component Analysis (PCA) clear differences between species and groups of species in contrasting ecosystems is shown. Thus, species-specific populations of flavonoids and compounds with similar physicochemical properties are a distinct regional product. In this regard, along with the search and selection of individual plant species based on the content of one compound, it seems appropriate to search for effective regional complexes of flavonoids

Antibacterial Activity Research of Sea Buckthorn Meal Flavonoids

The article presents the study results of the antibacterial activity of rutin and quercetin, as well as flavonoids sum extract obtained from the fat-free common sea buckthorn meal (Hippophae rhamnoides L.), in comparison with the state standard sample (SSS) of rutin. According to one of the strategies for effectiveness and therapeutic potential evaluating of biologically active substances (BAS), a man studied the physicochemical parameters of fat-free sea buckthorn meal and the component composition of the flavonoid complex isolated from it. Inhibition of test microorganism cultures by the studied flavonoids showed that quercetin detected the maximum antibacterial activity against B. subtilis and B. mesentericus: the zones diameter of microbial growth suppression exceeds the lysis zones diameter of the SSS rutin comparison sample – 20.0 ± 0.1 mm and 16.0 ± 0.1 mm, respectively, whereas in SSS rutin – 1.0 ± 0.1 mm and 10.0 ± 0.1 mm. The researchers determined the quercetin influence on changes in morphological characteristics of B. subtilis and B. mesentericus by comparing micro-preparations, samples of which were taken from the area of bacterial growth after treatment with quercetin. Thus, the cells of the hay bacillus noticeably decreased in size, and the cells of the potato bacillus changed shape – from stringformed to coccoid-formed, indicating the cells forwardness to a quiescent state, which is a way of survival in the adverse conditions caused by quercetin treatment. To quantify the antibacterial effect of flavonoids, a man developed the inhibition coefficient (Ki) of microbial growth; its maximum value in the quercetin sample is 1900.0% for B. subtilis and 60.0 % for B. mesentericus, which allows to consider this sea buckthorn meal flavanol as a promising micro-ingredient for food bioconservation.

Formulation of Orange Juice with Dietary Fibers Enhances Bioaccessibility of Orange Flavonoids in Juice but Limits Their Ability to Inhibit In Vitro Glucose Transport.

The effect of formulating orange juice (OJ) with dietary fibers (DFs) on in vitro bioaccessibility of flavonoids and their ability to inhibit glucose transport in Caco-2 cells were investigated on Valencia orange fruit (OF), OJ, and OJ formulated with 1 and 2.8% DFs. DFs were either orange pomace (P) or commercial pulverized citrus pulp fiber (CF). Juice extraction and formulation with CF led to minimal loss of flavonoids compared to formulation with P (474 μmol/100 g for OF vs 315-368 μmol/100 g for OJ and OJ with CF, and 266-280 μmol/100 g for OJ with P). Addition of DFs led to similar or improved flavonoid bioaccessibility compared to OJ (9.5% in OJ vs 7.9-33.4% with DFs) but higher glucose transport in Caco-2 cells (0.45 μmol/min in OJ alone vs 0.64-0.94 μmol/min with DFs). This paradoxical effect was attributed to potential complexation of flavonoids and DFs, preventing flavonoids from interfering with glucose transport.

Comparative analysis of the total quantity of flavonoids in domestic and imported raw material of stevia

Relevance. Standardization of plant raw material derived from stevia is a topical issue, since this plant (Stevia rebaudiana Bertoni) contains sweet diterpene glycosides and is used as a natural sugar substitute. In addition, stevia contains flavonoids which are biologically active compounds that exert antioxidant, anti-inflammatory and capillary-strengthening properties. Currently, spectrophotometric methods are used to identify and quantify flavonoids in medicinal plants. They are fast, convenient and do not require sophisticated equipment.
 The aim of our paper is comparative phytochemical study of the content of the total flavonoids in stevia raw material of different origin.
 Materials and methods. The study material was dried stevia leaves (Stevia rebaudiana Bertoni), grown in the Penza Region, the Republic of Crimea, the Krasnodar territory, and raw materials imported from Paraguay and India. The content of the total flavonoids was estimated by differential spectrophotometry calculated with reference to cynaroside.
 Results. The study of the quantity of flavonoids in the raw material of stevia of different origin was carried out. In the presence of aluminum chloride stevia flavonoids form a complex compound at the absorption maximum of 408 2 nm. The content of flavonoids in different species of stevia are found to range from 1.13% to 1.74%.
 Conclusion. The obtained results allow to recommend stevia leaves as a source of flavonoids along with other available medicinal plants. It is advisable to classify the complex of flavonoids as the second group of biologically active compounds of stevia leaves.