A mini-review of isolation, chemical properties and bioactivities of polysaccharides from buckwheat (Fagopyrum Mill)

Polysaccharides extracted from common buckwheat (Fagopyrum esculentum) attenuate cognitive impairment via suppressing RAGE/p38/NF-κB signaling and dysbiosis in AlCl3-treated rats

Patients may find it challenging to accept several FDA-approved drugs for Alzheimer's disease (AD) treatment due to their unaffordable prices and side effects. Despite the known antioxidant, anti-inflammatory, and microbiota-regulating effects of common buckwheat (Fagopyrum esculentum) polysaccharides (FEP), their specific role in preventing AD has not been determined. Here, this study investigated the preventive effects of FEP on AD development in AlCl3-treated rats. The physical properties of FEP were evaluated using X-ray diffraction, FTIR, TGA, DSC, monosaccharide composition, molecular weight, and scanning electron microscopy. The results demonstrated that FEP administration improved memory and learning ability in AlCl3-treated rats. Additionally, AD pathological biomarkers (APP, BACE1, Aβ1-42, and p-TauSer404), inflammatory-associated proteins (IL-1β, IL-6, TNF-α, and Iba1), and MDA and the RAGE/p38/NF-κB pathway were elevated in AlCl3-treated rats. Moreover, these effects were reversed by the upregulation of LRP1, anti-inflammatory cytokines (IL-4 and IL-10), antioxidant enzymes (SOD and catalase), and autophagy proteins (Atg5, Beclin-1, and LC3B). Furthermore, FEP treatment increased the levels of short-chain fatty acids (SCFAs) and the abundance of SCFAs-producing microbes ([Eubacterium]_xylanophilum_group, Lachnospiraceae_NK4A136_group, Lactobacillus). Overall, FEP mitigated oxidative stress, RAGE/p38/NF-κB-mediated neuroinflammation, and AD-associated proteins by upregulating autophagy and SCFA levels, which led to the amelioration of cognitive impairment through microbiota-gut-brain communication in AlCl3-treated rats.

Analysis of characteristic aromas of buckwheat with different germplasm using gas chromatography-mass spectrometry combined with chemometrics and multivariate statistical analysis

In this study, the volatile components in 40 samples of Tartary buckwheat and common buckwheat from 6 major producing areas in China were analyzed. A total of 77 volatile substances were identified, among which aldehydes and hydrocarbons were the main volatile components. Odor activity value analysis revealed 26 aromatic compounds, with aldehydes making a significant contribution to the aroma of buckwheat. Seven key compounds that could be used to distinguish Tartary buckwheat from common buckwheat were identified. The orthogonal partial least squares-discriminant analysis was effectively used to classify Tartary buckwheat and common buckwheat from different producing areas. This study provides valuable information for evaluating buckwheat quality, breeding high-quality varieties, and enhancing rational resource development.

Fagopyrins from Buckwheat Flowers: Structural and Stereochemical Characterization Through Combined NMR/CD Spectroscopy and Theoretical Calculations

Fagopyrins are phenantroperylenequinones present in the flowers of Fagopyrum esculentum (buckwheat) endowed with photodynamic activity. It has been reported that fagopyrin extracts actually contain a complex mixture of closely related compounds, differing only on the nature of the perylenequinone substituents. We report our systematic and detailed study on the chemical composition of fagopyrin extracts by a combination of preparative and analytical techniques. The combined use of 1H-NMR and CD spectroscopy was found to be particularly suited to fully characterize all stereochemical aspects of the extracted fagopyrins. For the first time nine isomers have been structurally characterized and their stereochemistry fully elucidated. The presence of two different heterocyclic ring substituents, two stereogenic centers and the inherent axial chirality of the aromatic system provides a complex stereochemical relationships among isomers, thus giving account of the high level of molecular multiplicity found in the extract.

DNA methylation analysis of floral parts revealed dynamic changes during the development of homostylous Fagopyrum tataricum and heterostylous F. esculentum flowers

BACKGROUND

Proper flower development is essential for plant reproduction, a crucial aspect of the plant life cycle. This process involves precisely coordinating transcription factors, enzymes, and epigenetic modifications. DNA methylation, a ubiquitous and heritable epigenetic mechanism, is pivotal in regulating gene expression and shaping chromatin structure. Fagopyrum esculentum demonstrates anti-hypertensive, anti-diabetic, anti-inflammatory, cardio-protective, hepato-protective, and neuroprotective properties. However, the heteromorphic heterostyly observed in F. esculentum poses a significant challenge in breeding efforts. F. tataricum has better resistance to high altitudes and harsh weather conditions such as drought, frost, UV-B radiation damage, and pests. Moreover, F. tataricum contains significantly higher levels of rutin and other phenolics, more flavonoids, and a balanced amino acid profile compared to common buckwheat, being recognised as functional food, rendering it an excellent candidate for functional food applications.

RESULTS

This study aimed to compare the DNA methylation profiles between the Pin and Thrum flower components of F. esculentum, with those of self-fertile species of F. tataricum, to understand the potential role of this epigenetic mechanism in Fagopyrum floral development. Notably, F. tataricum flowers are smaller than those of F. esculentum (Pin and Thrum morphs). The decline in DNA methylation levels in the developed open flower components, such as petals, stigmas and ovules, was consistent across both species, except for the ovule in the Thrum morph. Conversely, Pin and Tartary ovules exhibited a minor decrease in DNA methylation levels. The highest DNA methylation level was observed in Pin stigma from closed flowers, and the most significant decrease was in Pin stigma from open flowers. In opposition, the nectaries of open flowers exhibited higher levels of DNA methylation than those of closed flowers. The decrease in DNA methylation might correspond with the downregulation of genes encoding methyltransferases.

CONCLUSIONS

Reduced overall DNA methylation and the expression of genes associated with these epigenetic markers in fully opened flowers of both species may indicate that demethylation is necessary to activate the expression of genes involved in floral development.

Nutritive profile, pharmaceutical potentials, and structural analysis of multifunctional bioactive fungal polysaccharides-A review

Asian nations have long used edible fungi as food and medicine. Polysaccharides are among the main building units of the cell walls of fungi. Fungal polysaccharides have been documented in the medicinal and industrial sectors as products with a vast array of various biological activities and applications such as antitumor, antioxidant, anticancer, immunomodulation, and antiviral activities, etc. The goal of this review is to give insights into the various biological activities of mushroom polysaccharides and their potential as a medicine for human health. The extraction, purity, and structural analysis of fungal polysaccharides were also reviewed in this work. Also, future prospective, and challenges for fungal polysaccharides in pharmaceutical applications can be found in this review. Overall, this review serves as a valuable resource in exploring the therapeutic potential and applications of fungal polysaccharides. By building upon the existing knowledge base and addressing critical research gaps, researchers can find new opportunities for utilizing fungal polysaccharides as valuable therapeutic agents and functional ingredients in pharmaceuticals, nutraceuticals, and biotechnology.

Efficient and Selective Extraction of Rhamnogalacturonan-I-Enriched Pectic Polysaccharides from Tartary Buckwheat Leaves Using Deep-Eutectic-Solvent-Based Techniques

Tartary buckwheat green leaves are considered to be among the most important by-products in the buckwheat industry. Although Tartary buckwheat green leaves are abundant in pectic polysaccharides, their potential applications in the food industry are quite scarce. Therefore, to promote their potential applications as functional or fortified food ingredients, both deep-eutectic-solvent-assisted extraction (DESE) and high-pressure-assisted deep eutectic solvent extraction (HPDEE) were used to efficiently and selectively extract pectic polysaccharides from Tartary buckwheat green leaves (TBP). The results revealed that both the DESE and HPDEE techniques not only improved the extraction efficiency of TBP but also regulated its structural properties and beneficial effects. The primary chemical structures of TBP extracted using different methods were stable overall, mainly consisting of homogalacturonan and rhamnogalacturonan-I (RG-I) pectic regions. However, both the DESE and HPDEE methods could selectively extract RG-I-enriched TBP, and the proportion of the RG-I pectic region in TBP obviously improved. Additionally, both the DESE and HPDEE methods could improve the antioxidant and anti-glycosylation effects of TBP by increasing its proportion of free uronic acids and content of bound polyphenolics and reducing its molecular weight. Moreover, both the DESE and HPDEE methods could partially intensify the immunostimulatory effect of TBP by increasing its proportion of the RG-I pectic region. These findings suggest that DES-based extraction techniques, especially the HPDEE method, can be promising techniques for the efficient and selective extraction of RG-I-enriched TBP.

Structural properties and biological activities of soluble dietary fibers rich in pectic-polysaccharides from different buckwheat green leaves

Buckwheat green leaves are commonly consumed as functional tea materials due to their various beneficial effects. Although buckwheat green leaves have abundant soluble dietary fibers (SDFs), the information about their structural properties and functional properties remains unknown, largely hindering their applications as functional/health products. Hence, to enhance the usage and application of SDFs from buckwheat green leaves as value-added health products, the structures and biological activities of SDFs derived from different buckwheat green leaves were investigated and compared. Results revealed that SDFs derived from Tartary buckwheat green leaves (TBSDF) and common buckwheat green leaves (CBSDF) were rich in complex pectic-polysaccharides, mainly composing of homogalacturonan (HG) and rhamnogalacturonan I (RG I) pectic domains. Besides, TBSDF had higher proportion of RG I pectic domains than that of CBSDF. Furthermore, the existence of a high content of complex pectic-polysaccharides in TBSDF and CBSDF could contribute to their various biological activities, such as antioxidant, antiglycation, fat/bile acid binding, anticancer, and prebiotic effects. These results can provide some new insights into further development of buckwheat green leaves and related SDFs as value-added health products.

Extraction, purification, structural characterization and biological activity of polysaccharides from Fritillaria: A review

Fritillaria is a traditional Chinese medicine(TCM) with a history of thousands of years. Fritillaria always contain saponins, alkaloids, amino acids, flavones, and polysaccharides. Among them, Fritillaria polysaccharide has a variety of biological activities. Its anti-inflammatory and antiaging activities are new study hotspots. The extraction, purification, quantitative determination, monosaccharide composition, and biological activity of Fritillaria polysaccharides have been examined for several years in an attempt to identify the active components and understand the pharmacological process. In this review, ample original publications related to the distribution, extraction, purification, quantitative determination, monosaccharide composition and biological activities of Fritillaria until 2023 were searched and collected by using various literature databases. Databases included the China National Knowledge Infrastructure, VIP database, Wan Fang database, PubMed, Elsevier, Springer, Science Direct, Google Scholar and Web of Science database, as well as the classic Chinese medical books and PhD and MSc theses. The properties and outcomes of various extractions, purifications, quantitative determination methods, monosaccharide compositions, and biological activities of Fritillaria polysaccharides are discussed here. Additionally, we summarize the research potential of Fritillaria polysaccharide and identify promising research direction candidates.

Physicochemical characterization, rheological properties, and hypolipidemic and antioxidant activities of compound polysaccharides in Chinese herbal medicines by fractional precipitation

This study aimed to investigate the effects of different compound polysaccharides (CPs) extracted from Folium nelumbinis, Fructus crataegi, Fagopyrum tataricum, Lycium barbarum, Semen cassiae, and Poria cocos (w/w, 2:4:2:1:1.5:1) by gradient ethanol precipitation on the physicochemical properties and biological activities. Three CPs (CP50, CP70, and CP80) were obtained and comprised rhamnose, arabinose, xylose, mannose, glucose, and galactose in different proportions. The CPs contained different amounts of total sugar, uronic acid, and proteins. These also exhibited different physical properties, including particle size, molecular weight, microstructure, and apparent viscosity. Scavenging abilities of 2,2'-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS), 1,1'-diphenyl-2-picrylhydrazyl (DPPH), hydroxyl, and superoxide radicals of CP80 were more potent compared to those of the other two CPs. Furthermore, CP80 significantly increased serum levels of high-density lipoprotein cholesterol (HDL-C) and lipoprotein lipase (LPL), and hepatic lipase (HL) activity in the liver, while decreasing the serum levels of total cholesterol (TC), triglyceride (TG), and low-density lipoprotein cholesterol (LDL-C), along with LPS activity. Therefore, CP80 may serve as a natural novel lipid regulator in the field of medicinal and functional food.

The Colonization and Effect of Isaria cateinannulata on Buckwheat Sprouts

The use of entomogenous fungi as endophytes is currently an area of active research. Isaria cateniannulata is an important entomogenous fungus that has been employed for the active control of a range of pests in agricultural and forestry settings, but its direct impact on plants remains to be evaluated. Herein, we assessed the ability of I. cateniannulata to colonize buckwheat, Fagopyrum esculentum and F. tataricum, and its impact on buckwheat defense enzyme activity and physiological indexes. The majority of fungal submerge condia was able to enter into leaves through stomata and veins, and this was followed by conidial attachment, lytic enzyme secretion, conidial deformation, and enhanced defensive enzyme activity within buckwheat, followed by the repair of damaged tissue structures. I. cateniannulata populations on buckwheat leaf surfaces (in CFU/g) reached the minimum values at 24 h after inoculation. At this time, the blast analysis revealed that the sequence identity values were 100%, which was consistent with the sequence of I. cateniannula. The number of I. cateniannulata submerge conidia colonized in the buckwheat leaves gradually rose to peak levels on 7 d post-inoculation, and then gradually declined until 10 d, at which time the buckwheat plant growth index values increased. This study provided novel evidence that I. cateniannulata could be leveraged as an endophytic fungus capable of colonizing buckwheat plants and promoting their growth.

Systematic Review of Human and Animal Evidence on the Role of Buckwheat Consumption on Gastrointestinal Health

BACKGROUND

Buckwheat is a commonly cultivated crop with growing evidence that it is beneficial to gastrointestinal (GI) health. This systematic review summarizes the role of buckwheat in modifying GI health outcomes and microbiomes.

METHODS

Four medical databases and Google Scholar were systematically searched. Clinical trials, observational studies, animal in vivo, and in vitro studies with human and animal GI-derived samples were included.

RESULTS

There were 32 studies (one randomized controlled trial [RCT], one non-randomized trial, 3 observational, 9 in vitro, and 18 animal in vivo studies) included. In preclinical studies, buckwheat extracts were observed to have cytotoxic potential against human-derived GI cancer cell lines. Animals fed with buckwheat had lower GI mucosal inflammation, higher alpha diversity in the GI microbiome, and higher levels of fecal short-chain fatty acids. Human evidence studies and clinical trials were limited and predominantly of moderate risk of bias. The majority of in vitro studies with GI-derived samples and in vivo studies were reliable without restrictions in study design.

CONCLUSION

In vivo and in vitro studies show that buckwheat may have potential GI benefits due to its anti-oxidant and anti-inflammatory potential; however, human evidence remains limited, and its impact on health in humans remains to be elucidated in future trials.

Exploring the Valorization of Buckwheat Waste: A Two-Stage Thermo-Chemical Process for the Production of Saccharides and Biochar

To realize the utilization of the valorization of buckwheat waste (BW), a two-stage thermal-chemical process was explored and evaluated to produce saccharides and biochar. During the first stage, BW underwent a hydrothermal extraction (HTE) of varying severity to explore the feasibility of saccharides production; then, the sum of saccharides yields in the liquid sample were compared. A higher sum of saccharides yields of 4.10% was obtained at a relatively lower severity factor (SF) of 3.24 with a byproducts yield of 1.92 %. During the second stage, the contents of cellulose, hemicellulose, and lignin were analyzed in the residue after HTE. Enzymatic hydrolysis from the residue of HTE was inhibited. Thus, enzymatic hydrolysis for saccharides is not suitable for utilizing the residue after HTE of BW. These residues with an SF of 3.24 were treated by pyrolysis to produce biochar, providing a higher biochar yield of 34.45 % and a higher adsorption ability (based on methyl orange) of 31.11 % compared with pyrolysis of the raw BW. Meanwhile, the surface morphology and biomass conversion were analyzed in this study. These results demonstrate that the two-stage thermal-chemical process is efficient for treating BW and producing saccharides and biochar. This work lays a foundation for the industrial application of BW, and for improving the economic benefits of buckwheat cultivation.

A review of extraction, purification, structural properties and biological activities of legumes polysaccharides

In recent years, polysaccharides derived from legumes polysaccharides have aroused worldwide interests. Phytochemical and pharmacological studies have studied the physicochemical properties (emulsification, stability and foaming) and demonstrated the biological activities (immune regulation, anti-oxidation, anti-tumor, hypoglycemic, hypolipidemic and intestinal flora regulation) of legumes polysaccharides. Besides, it is reported that the extraction methods will affect the structural features of polysaccharides, thus further changing their physicochemical properties and biological activities. This review appraised the available literatures described the extraction, purification, structural characterization, biological activity and functional properties of legumes polysaccharides in recent years. It can provide useful research underpinnings and updated information for the development and application of related polysaccharides in functional food and medicinal field.

Polysaccharides from fungi: A review on their extraction, purification, structural features, and biological activities

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A variety of extraction methods of polysaccharides from fungi are reviewed and compared.

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Purification methods, structure of fungal polysaccharides were reviewed.

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Diverse biological activities of fungal polysaccharides were outlined.

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Structure-activity relationships of fungal polysaccharides were discussed.

Fungi, as the unique natural resource, are rich in polysaccharides, proteins, fats, vitamins, and other components. Therefore, they have good medical and nutritional values. Polysaccharides are considered one of the most important bioactive components in fungi. Increasing researches have confirmed that fungal polysaccharides have various biological activities, such as antioxidant, immunomodulatory, anti-tumor, hepatoprotective, anti-aging, anti-inflammatory, and radioprotective activities. Consequently, the research progresses and future prospects of fungal polysaccharides must be systematically reviewed to promote their better understanding. This paper reviewed the extraction, purification, structure, biological activity, and underlying molecular mechanisms of fungal polysaccharides. Moreover, the structure–activity relationships of fungal polysaccharides were emphasized and discussed. This review can provide scientific basis for the research and industrial utilization of fungal polysaccharides.

Research progress on extraction, purification, structure and biological activity of Dendrobium officinale polysaccharides

Dendrobium officinale Kimura et Migo (D. officinale) is a traditional medicinal and food homologous plant that has been used for thousands of years in folk medicine and nutritious food. Recent studies have shown that polysaccharide is one of the main biologically active components in D. officinale. D. officinale polysaccharides possess several biological activities, such as anti-oxidant, heptatoprotective, immunomodulatory, gastrointestinal protection, hypoglycemic, and anti-tumor activities. In the past decade, polysaccharides have been isolated from D. officinale by physical and enzymatic methods and have been subjected to structural characterization and activity studies. Progress in extraction, purification, structural characterization, bioactivity, structure-activity relationship, and possible bioactivity mechanism of polysaccharides D. officinale were reviewed. In order to provide reference for the in-depth study of D. officinale polysaccharides and the application in functional food and biomedical research.

Buckwheat in Tissue Culture Research: Current Status and Future Perspectives

Buckwheat is a member of a genus of 23 species, where the two most common species are Fagopyrum esculentum (common buckwheat) and Fagopyrum tataricum (Tartary buckwheat). This pseudocereal is a source of micro and macro nutrients, such as gluten-free proteins and amino acids, fatty acids, bioactive compounds, dietary fibre, fagopyrins, vitamins and minerals. It is gaining increasing attention due to its health-promoting properties. Buckwheat is widely susceptible to in vitro conditions which are used to study plantlet regeneration, callus induction, organogenesis, somatic embryogenesis, and the synthesis of phenolic compounds. This review summarises the development of buckwheat in in vitro culture and describes protocols for the regeneration of plantlets from various explants and differing concentrations of plant growth regulators. It also describes callus induction protocols as well as the role of calli in plantlet regeneration. Protocols for establishing hairy root cultures with the use of Agrobacterium rhizogens are useful in the synthesis of secondary metabolites, as well as protocols used for transgenic plants. The review also focuses on the future prospects of buckwheat in tissue culture and the challenges researchers are addressing.

Optimization of the Multienzyme-Assisted Extraction Procedure of Bioactive Compounds Extracts from Common Buckwheat (Fagopyrum esculentum M.) and Evaluation of Obtained Extracts

Optimization of the extraction procedure using a multienzymes cocktail for common buckwheat (Fagopyrum esculentum M.) is important due to the yield, fermentable sugars, oligosaccharides and bioactive compounds for creating higher added value products. This study was undertaken to find out the optimum multienzymes-water extraction on yield and total phenolic compounds for common Buckwheat using response surface methodology (RSM). Three independent variables, time (2, 13, and 24 h), temperature (60 °C, 70 °C, 80 °C), and non-starch polysaccharide (NSP) enzymes mixture (0.10, 0.55, and 1.00 mL), were analyzed to optimize the response variables. NSP hydrolyzing enzymes, cellulase, xylanase, and β-glucanase, were produced by Trichoderma reesei. Estimated optimum conditions for F. esculentum were found: time-2 h, temperature-65 °C, and cellulase activity-8.6 CellG5 Units/mL. Different optimization run samples were collected and lyophilized for further analysis until the hydrophilic property using the water contact angle methodology and rutin content using HPLC was determined. Results indicated NSP enzymes activity did not differ between water contact angles after 13 h of enzymatic water extraction. However, longer fermentation time (24 h) decreased static water contact angle by approximately 3-7° for lyophilized water extract and 2-7° for solid fraction after fermentation. It implies enzymatic hydrolysis during water extraction increased hydrophilic properties in solid fraction and decreased hydrophilicity in water fraction due to the enzymes cleaved glycosidic bonds releasing water-soluble compounds.

Bioactive compounds, health benefits, and industrial applications of Tartary buckwheat (Fagopyrum tataricum)

Tartary buckwheat belongs to the family Polygonaceae, which is a traditionally edible and medicinal plant. Due to its various bioactive compounds, the consumption of Tartary buckwheat is correlated to a wide range of health benefits, and increasing attention has been paid to its potential as a functional food. This review summarizes the main bioactive compounds and important bioactivities and health benefits of Tartary buckwheat, emphasizing its protective effects on metabolic diseases and relevant molecular mechanisms. Tartary buckwheat contains a wide range of bioactive compounds, such as flavonoids, phenolic acids, triterpenoids, phenylpropanoid glycosides, bioactive polysaccharides, and bioactive proteins and peptides, as well as D-chiro-inositol and its derivatives. Consumption of Tartary buckwheat and Tartary buckwheat-enriched products is linked to multiple health benefits, e.g., antioxidant, anti-inflammatory, antihyperlipidemic, anticancer, antidiabetic, antiobesity, antihypertensive, and hepatoprotective activities. Especially, clinical studies indicate that Tartary buckwheat exhibits remarkable antidiabetic activities. Various tartary buckwheat -based foods presenting major health benefits as fat and blood glucose-lowering agents have been commercialized. Additionally, to address the safety concerns, i.e., allergic reactions, heavy metal and mycotoxin contaminations, the quality control standards for Tartary buckwheat and its products should be drafted and completed in the future.

Biopolymer-derived (nano)catalysts for hydrogen evolution via hydrolysis of hydrides and electrochemical and photocatalytic techniques: A review

Over the course of a few decades, the concern of environmental damages of fossil fuels, an increase in CO₂ emission and a decrease of hydrogen have been growing more and more. Accordingly, hydrogen production is a crucial issue nowadays. Different polymers are applied to attain the purpose. Among all polymers, biodegradables polymers are the best choices to develop the main aim. Polysaccharides and proteins are biodegradable polymers with unique places and advantages with regards to their ecofriendly properties. There are different techniques to apply and achieve the foremost purpose. It is worthwhile to mention that green and facile methods are always attracting attention in different aspects and fields. The three non-polluting and economical techniques, that is, electrochemical hydrogen evolution reaction (HER), photocatalytic technique, and hydrolysis of hydrides, are reviewed in this paper. This review helps researchers, who are environment supporters, to evaluate and choose the most ecological biopolymers and processes in their work.

Identification of Potential Peptide Inhibitors of ACE-2 Target of SARS-CoV-2 from Buckwheat & Quinoa

It is well established fact that peptides from various foods offer human health benefits displaying diverse functionalities. Millets considered as super foods is a major alternative in recent days for traditional diet being rich in proteins and fibre along with trace minerals and vitamins. In this connection, proteins from Buckwheat and Quinoa were digested by in vitro simulation digestion for the generation of peptides, analyzed by nLC-MS/MS and the functional annotations of the identified proteins/peptides were carried out. The study led to the identification of 34 small peptides and their parent proteins clustered into 4 gene functional groups and their localization prediction indicated their involvement in energy metabolism, transport and storage. Interestingly, the identified peptides maximally displayed DPP-IV and ACE inhibitions. The present study was extended to unravel ACE-2 inhibition targeting COVID-19 by selecting ACE-2-Spike binding domain for molecular docking studies. The NWRTVKYG interacted with the ACE-2-Spike interface displaying the feasible binding energy (− 213.63) and docking score (− 12.43) and the MD simulation revealed the ability of the peptide in stabilizing the protein-peptide composite. The present investigation thus establishes newer vista for food derived peptides having ACE-2 inhibitory potential as tentative strategy for SARS-CoV-2 therapeutics.

Pectic polysaccharides from edible halophytes: Insight on extraction processes, structural characterizations and immunomodulatory potentials

The preparation, chemical properties and bio-activities of polysaccharides derived from halophytes have gained an increasing interest in the past few years. Phytochemical and pharmacological reports have shown that carbohydrates are important biologically active compounds of halophytes with numerous biological potentials. It is believed that the mechanisms involved in these bio-activities are due to the modulation of immune system. The main objective of this summary is to appraise available literature of a comparative study on the extraction, structural characterizations and biological potentials, particularly immunomodulatory effects, of carbohydrates isolated from halophytes (10 families). This review also attempts to discuss on bioactivities of polysaccharides related with their structure-activity relationship. Data indicated that the highest polysaccharides yield of around 35% was obtained under microwave irradiation. Structurally, results revealed that the most of extracted carbohydrates are pectic polysaccharides which mainly composed of arabinose (from 0.9 to 72%), accompanied by other monosaccharides (galactose, glucose, rhamnose, mannose and xylose), significant amounts of uronic acids (from 18.9 to 90.1%) and some proportions of fucose (from 0.2 to 8.3%). The molecular mass of these pectic polysaccharides was varied from 10 to 2650 kDa. Hence, the evaluation of these polysaccharides offers a great opportunity to discover novel therapeutic agents that presented especially beneficial immunomodulatory properties. Moreover, reports indicated that uronic acids, molecular weights, as well as the presence of sulfate and unmethylated acidic groups may play a significant role in biological activities of carbohydrates from halophyte species.

Breeding Buckwheat for Increased Levels and Improved Quality of Protein

Tartary buckwheat (Fagopyrum tataricum (L.) Gaertn.) and common buckwheat (Fagopyrum esculentum Moench) are important sources of proteins with balanced amino-acid compositions, and thus of high nutritional value. The polyphenols naturally present in Tartary buckwheat and common buckwheat lower the true digestibility of the proteins. Digestion-resistant peptides are a vehicle for fecal excretion of steroids, and in this way, for bile acid elimination and reduction of cholesterol concentrations in serum. Buckwheat proteins are more effective compared to soy proteins for the prevention of gallstone formation. Tartary and common buckwheat grain that contains appropriate amounts of selenium-containing amino acids can be produced as functional food products. The protein-rich by-products of buckwheat are a good source of bioactive substances that can suppress colon carcinogenesis by reducing cell proliferation. The grain embryo is a rich source of proteins, so breeding buckwheat with larger embryos is a possible strategy to increase protein levels in Tartary and common buckwheat grain. However, chemical analysis of the grain is the most relevant criterion for assessing grain protein levels and quality.

A polysaccharide from Fagopyrum esculentum Moench bee pollen alleviates microbiota dysbiosis to improve intestinal barrier function in antibiotic-treated mice

Antibiotics are the most commonly used clinical drugs for anti-infection, but they can also destroy normal microorganisms and cause intestinal barrier dysfunction. To elucidate the effects and mechanism of a water-soluble polysaccharide from Fagopyrum esculentum Moench bee pollen (WFPP) on intestinal barrier integrity in antibiotic-treated mice, BALB/c mice were exposed to a broad-spectrum antibiotic (ceftriaxone) or not (control), and were administered low-, medium- and high-dose WFFP (100 mg kg^-1, 200 mg kg^-1 and 400 mg kg^-1, respectively) daily by oral gavage for 3 weeks. Mice treated with ceftriaxone displayed symptoms of growth retardation, atrophy of immune organs including thymus and spleen, increased gut permeability, and intestinal barrier damage, which were restored after intervention with WFFP at different doses. Moreover, the beneficial effects of WFFP were closely associated with enhanced intestinal sIgA secretion and reduced inflammatory response. Furthermore 16S rDNA gene sequencing revealed that WFPP elevated microbial diversity and richness and changed the community structure, therefore, alleviating microbiota dysbiosis caused by ceftriaxone. Interestingly, WFPP could modulate the abundance of sIgA secretion-related bacteria (e.g. Proteobacteria) and inflammation-related bacteria (e.g. Enterococcus). Therefore, WFPP can relieve antibiotic-induced microbiota dysbiosis to improve intestinal barrier integrity by increasing intestinal sIgA secretion and inhibiting inflammation.

Treasure from garden: Bioactive compounds of buckwheat

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An extensive review on diverse bioactive components of buckwheat.

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Versatile beneficial phytochemicals are abundant in buckwheat.

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Buckwheat has a wide range of pharmacological and beneficial health effects.

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Huge research scope on Fagopyrum cymosum to identify the beneficial phytochemicals.

Buckwheat is a gluten-free crop under the family Polygonaceae abundant with beneficial phytochemicals that provide significant health benefits. It is cultivated and adapted in diverse ecological zones all over the world. Recently its popularity is expanding as a nutrient-rich healthy food with low-calories. The bioactive compounds in buckwheat are flavonoids (i.e., rutin, quercetin, orientin, isoorientin, vitexin, and isovitexin), fatty acids, polysaccharides, proteins, and amino acids, iminosugars, dietary fiber, fagopyrins, resistant starch, vitamins, and minerals. Buckwheat possesses high nutritional value due to these bioactive compounds. Additionally, several essential bioactive factors that have long been gaining interest because these compounds are beneficial for healing and preventing several human diseases. The present review demonstrates an overview of the recent researches regarding buckwheat phytochemicals and particularly focusing on the distinct function of bioactive components with their health benefits.

A Review of Isolation, Chemical Properties, and Bioactivities of Polysaccharides from Bletilla striata

Recently, polysaccharides from Bletilla striata, a member of the orchidaceous family, aroused the wide interest of people, especially their isolation, chemical properties, and bioactivities. It is reported that these polysaccharides are the most important biologically active components of B. striata, exhibiting various biological activities, such as immunomodulatory, antioxidant, antifibrotic, and hemostatic effects. This review appraised the available literatures which described different aspects of B. striata polysaccharides, including the extraction, separation, purification, structural characterization, and biological activities. We expect to lay the foundation for further investigation of the application of B. striata polysaccharides in the field of functional foods and biomedicine.

Pseudocereals: a novel source of biologically active peptides

The interest in the research about underexploited foods has increased in the last two decades. Pseudocereals have been consumed by the ancient populations for hundreds of years. These plants that do not belong to the family of cereals, but that have properties and uses similar to them, stand out among underexploited foods. Some of the most representative species are quinoa, amaranth, chia and buckwheat. They do not contain gluten but high valued proteins and peptides can be obtained from them, as well as other nutritional and bioactive compounds such as flavonoids, phenolic acids, fatty acids, vitamins and minerals. Anticancer, antioxidant, anti-inflammatory, hypocholesterolemic and antihypertensive properties have been found and postulated for pseudocereals protein derived peptides. These interesting characteristics of pseudocereals are producing an increase of the relevance of these crops. The purpose of this work was to carry out an exhaustive revision of the scientific literature describing the biological activities of peptides and protein hydrolysates obtained from the most widely studied pseudocereals: quinoa, amaranth, chia and buckwheat.

Tartary Buckwheat Extract and Chitosan Coated Tilapia (Oreochromis Niloticus) Fillets Determine Their Shelf Life

The preservation effects of tartary buckwheat extract (T) and chitosan (C) coatings on the physicochemical (pH value, thiobarbituric acid value, Peroxide value (PV), total volatile basic nitrogen (TVB-N), K value, surface color and the texture profiles), bacteriological (total viable counts (TVC) and psychrotrophic bacteria counts (PBC)), and sensory characteristics of tilapia (Oreochromis niloticus) fillets storage at 0 °C for 18 days were evaluated. The fillets coated with 0.5% T + 1.0% C, 1.0% T + 1.0% C and 1.5% T + 1.0% C maintained better quality and had longer shelf life with respect to samples coated with chitosan alone and the control. Base on the limit values of TVB-N, K value, TVC and sensory preference scores, the shelf life of control fillets was 6 days. By contrast, shelf life of 9 days for 0.5% T + 1.0% C-coated fillets, 12 days for 1.0% T + 1.0% C treated-fillets, and 15 days for 1.5% T + 1.0% C-treated fillets were obtained. Therefore, TBE combined with chitosan coatings have the potential to extend the shelf life of tilapia fillets during storage at 0 °C. PRACTICAL APPLICATION: This study provides basic theory regarding the application of TBE to fish preservation. The edible coating of TBE combined with chitosan has potential use in developing activity food preservation coating.