Rye flavonoids – Structural profile of the flavones in diverse varieties and effect of fermentation and heat on their structure and antioxidant properties

Mechanisms of flavonoid inhibition of Maillard reaction product formation in relation to whole grains processing

Whole grains (WG) are beneficial to health but have reduced sensory quality, partly attributable to inhibition of Maillard reaction products (MRP) by WG phenolics. The study investigated how major flavonoid classes in cereals affect Maillard reaction pathways. Flavonoids were reacted with xylose-lysine aqueous system at 160 °C/12 min. Additionally, breads were made with catechin, and wheat and sorghum bran fortification. Low Mw MRP were profiled using UPLC-MS/MS, while melanoidins were characterized using fluorescence spectroscopy and HPSEC-MALS. The flavonoids significantly (p < 0.05) reduced both melanoidin content (by 33-86%) and Mw (3.5-15 kDa vs 20 kDa control), leading to lighter bread crust. Flavonoids inhibited MRP via direct condensation with early-stage amines and carbonyls into stable adducts, and reduction of late-stage polymerization reactions, increasing accumulation of cyclic N-containing intermediates. Inhibitory trend was flavones>flavanones>flavanols. C-Ring π-bond dramatically enhance flavonoid MRP inhibition; thus flavone-rich cereal grains are likely to strongly impact MRP-dependent sensory attributes of WG products.

Polyphenol recovery from sorghum bran waste by microwave assisted extraction: Structural transformations as affected by grain phenolic profile

Sorghum milling waste stream (bran), contains diverse phenolic compounds with bioactive properties. The study determined the potential of microwave assisted extraction (MAE) to recover the bran phenolic compounds. Red, white, and lemon-yellow pericarp sorghum brans were subjected to MAE and phenolic yield and structural transformation vs conventional extraction (control) assessed by UPLC-MS/MS, Folin-Ciocalteu and Trolox equivalent antioxidant capacity methods. Phenols yield increased from 3.7-20.3 to 12.6-75.5 mg/g, while antioxidants capacity increased average 3.3X in MAE extracts vs controls. Hydroxycinnamic acids increased most dramatically (3.0-32X) in MAE extracts (0.08-2.64 to 2.57-8.01 mg/g), largely driven by release of cell-wall derived feruloyl- and coumaroyl-arabinose. MAE hydrolyzed flavonoid glycosides into aglycones, and depolymerized condensed flavonoid heteropolymers into flavanones, flavanols and (deoxy)anthocyanidins. Thus, MAE dramatically enhances yield of valuable phenolics from sorghum bran waste, but also alters the phenolic profile in ways that may influence their chemical and biological properties.

Pinobanksin from peony seed husk: A flavonoid with the potential to inhibit the proliferation of SH-SY5Y

Pinobanksin, as one of the flavonoids, has powerful biological activities but has been under-recognized. In this study, we optimized the extraction method of phragmites from peony seed shells by using organic solvent extraction. The yield of PSMS was 10.54 ± 0.13% under the conditions of ethanol volume fraction 70%, extraction temperature 70°C, material-liquid ratio 1:25 g/mL, and extraction time 60 min; the optimized PSMS could be effectively separated in S-8 macroporous resin coupled with C18. The relative content of PSMS was increased from 0.42% in PSMS to 92.53% after C18 purification; the antioxidant activity test revealed that pinobanksin could exert antioxidant ability by binding catalase (CAT) enzyme. Second, it was found that pinobanksin could effectively inhibit the proliferation of SH-SY5Y cells, mainly by binding to BCL2-associated X (BAX), B-cell lymphoma-2 (BCL-2), and cyclin-dependent Kinase 4/6 (CDK4/6) to produce more hydrogen bonds to inhibit their activities. This study confirms the medicinal potential of pinobanksin and provides the basis for the proper understanding of pinobanksin and the development of related products.

Integrated Analysis of Metabolomics Combined with Network Pharmacology and Molecular Docking Reveals the Effects of Processing on Metabolites of Dendrobium officinale

Dendrobium officinale (D. officinale) is a precious medicinal species of Dendrobium Orchidaceae, and the product obtained by hot processing is called "Fengdou". At present, the research on the processing quality of D. officinale mainly focuses on the chemical composition indicators such as polysaccharides and flavonoids content. However, the changes in metabolites during D. officinale processing are still unclear. In this study, the process was divided into two stages and three important conditions including fresh stems, semiproducts and "Fengdou" products. To investigate the effect of processing on metabolites of D. officinale in different processing stages, an approach of combining metabolomics with network pharmacology and molecular docking was employed. Through UPLC-MS/MS analysis, a total of 628 metabolites were detected, and 109 of them were identified as differential metabolites (VIP ≥ 1, |log2 (FC)| ≥ 1). Next, the differential metabolites were analyzed using the network pharmacology method, resulting in the selection of 29 differential metabolites as they have a potential pharmacological activity. Combining seven diseases, 14 key metabolites and nine important targets were screened by constructing a metabolite-target-disease network. The results showed that seven metabolites with potential anticoagulant, hypoglycemic and tumor-inhibiting activities increased in relative abundance in the "Fengdou" product. Molecular docking results indicated that seven metabolites may act on five important targets. In general, processing can increase the content of some active metabolites of D. officinale and improve its medicinal quality to a certain extent.

An Overview of Bioactive Phenolic Molecules and Antioxidant Properties of Beer: Emerging Trends

Beer is one of the oldest and most common beverages worldwide. The phenolic contents and antioxidant properties of beer are crucial factors in evaluating its nutritional quality. Special beers brewed with the addition of adjuncts are gaining in consumer preference, in response to demands for healthy food and new gustatory and olfactory stimuli. Many studies recently dealt with functional beers brewed with the addition of adjuncts. This review focuses on bioactive molecules, particularly the composition of phenolic compounds, and the antioxidant activity of beer. The current knowledge concerning the effect of the addition of adjuncts in the form of fruit, vegetables, herbs, and natural foods on the polyphenol content, antioxidant properties, and phenolic profile of beer is reviewed, with an outline of the emerging trends in brewing processes. Future studies need to complete the identification and characterization of the bioactive molecules in beer, as well as studying their absorption and metabolic fate in humans.

Changes in Bio-Functional Compounds, ACE Inhibition, and Antioxidant Capacity after Mixed Fermentation of Eight Whole Grains

Whole grains are rich in nutrients and antioxidants and can be fermented to increase their biological functions. This study used two fermentation steps to ferment eight whole grains. The bio-functional compounds, ACE inhibition, and antioxidant capacity were measured during the second fermentation step. The results indicate that the total phenols content increased by 2605%, total flavonoid content increased by 1707%, ABTS radical scavenging capacity increased by 239%, DPPH radical scavenging capacity increased by 325%, GABA increased by 4810%, glucuronic acid increased by 4278%, ACE inhibition increased by 69.28%, and total amino acids increased by 2197.72% after 13 weeks of fermentation. These results showed that a fermentation beverage with eight whole grains could be considered a drink with health benefits.

Metabolomics based inferences to unravel phenolic compound diversity in cereals and its implications for human gut health

Background

Scope and approach

Key findings and conclusion

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Phenolic compounds are critical in avoiding metabolic disorders associated with oxidative stress.

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Breeding cereal crops to enrich phenolic compounds in grains contributes to personalized nutrition.

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A diet rich in cereal phenolics likely to increase human gut health, thereby lowering the risk of non-communicable illness.

Comparing the LC-MS Phenolic Acids Profiles of Seven Different Varieties of Brown Rice (Oryza sativa L.)

Brown rice, an important material of whole-grain food, is increasingly popular for its health benefits. Thus, seven varieties of brown rice from southern China were analyzed in this study, concerning the free and bound phenolic compounds in the extract. The phenolic profiles of different brown rice were obtained and compared by the combination of HPLC and LC-MS analysis, in which eleven phenolic acids were identified. It was indicated that the total phenolic contents of different brown rice varied from 92.32 to 196.54 mg of gallic acid equivalent (GAE)/100 g DW. Ferulic acid and p-coumaric acid, free and bound, dominated within the phenolic acids. To be mentioned, the total phenols of Luotiangongmi (a kind of red rice) were significantly higher than the other six varieties. The high phenolic content of brown rice can further guide us to explore the functional properties of the crops.

Rye Flour and Rye Bran: New Perspectives for Use

Rye (Secale cereale L.) is abundantly cultivated in countries like Europe and North America, particularly in regions where soil and climate conditions are unfavorable for the growth of other cereals. Among all the cereals generally consumed by human beings, rye grains are characterized by the presence of the highest content of fiber. They are also a rich source of many phytochemical compounds, which are mainly distributed in the outer parts of the grain. This review focuses on the current knowledge regarding the characteristics of rye bran and wholemeal rye flour, as well as their applications in the production of both food and nonfood products. Previous studies have shown that the physicochemical properties of ground rye products are determined by the type of milling technique used to grind the grains. In addition, the essential biologically active compounds found in rye grains were isolated and characterized. Subsequently, the possibility of incorporating wholemeal rye flour, rye bran, and other compounds extracted from rye bran into different industrial products is discussed.

Kaempferide enhances antioxidant capacity to promote osteogenesis through FoxO1/β-catenin signaling pathway

BACKGROUND

Forkhead box O1 (FoxO1)/β-catenin signaling pathway is a main oxidative defense pathway, which plays essential roles in the regulation of osteoporosis (OP). The natural products possess quality therapeutic effects and few side effects. It is used as a novel strategy in the treatment of OP. However, there is no systematic study in the natural antioxidant drug based on the FoxO1/β-catenin signaling pathway. This paper aims to discover pro-osteogenesis natural antioxidants for the prevention and treatment of OP.

METHODS

Systems pharmacology; combined with reverse drug targeting, systems-ADME process, network analysis and molecular docking, was used to screen natural antioxidants based on the FoxO1/β-catenin signaling pathway. Then in vitro experiments were performed to evaluate the osteogenesis effects of screened natural antioxidants.

RESULTS

Kaempferide was screened as the most potential antioxidant to improve osteogenesis by the regulation of the FoxO1/β-catenin signaling pathway. In vitro experiments showed that kaempferide significantly increased the expression of antioxidant genes and promoted osteogenic differentiation. Furthermore, kaempferide also improved the osteogenic differentiation inhibited by H2O2 through the enhancement of antioxidant capacity. Notably, kaempferide promoted cell antioxidant capacity by the increased nuclear translocation of FoxO1 and β-catenin.

CONCLUSIONS

These findings suggest that kaempferide is the natural antioxidant to promote osteogenesis effectively through the FoxO1/β-catenin signaling pathway. Natural antioxidant therapy maybe a promising strategy for the prevention and treatment of OP.

Changes in extractable phenolic profile during natural fermentation of wheat, sorghum and teff

Whole grain polyphenols are associated with structure-specific bioactive properties. However, the phenolic profile of grain ingredients can be significantly altered by processes like fermentation. This study investigated how polyphenol profiles in different cereal grains respond to microbial metabolism during sourdough fermentation. Whole grain wheat (white and red), sorghum (white and lemon-yellow), and teff (white and brown) flours were subjected to natural sourdough fermentation for 48-96 h, and phenolic profiles and their metabolites monitored using UPLC-tandem quadrupole MS. Flavonoid O-glycosides (dominant in sorghum) were rapidly metabolized (66% reduction in 48 h) to release aglycones (2.5 fold increase). O-Glycoside groups in mixed O/C-glycosides (dominant in teff) were selectively hydrolyzed, but more slowly (11-32% reduction in 48 h) than homo-O-glycosides, suggesting steric hindrance from the C-glycoside groups. Flavonoid C-glycosides (dominant in wheat) and aglycones (white sorghum) were generally stable to microbial degradation. Extractable phenolic acids and their esters (most abundant in white sorghum) were extensively degraded (80% reduction in 48 h) with few metabolites detected at the end of fermentation. Thus, extractable phenolics in sorghum were generally most extensively metabolized, whereas those in wheat were the least impacted by sourdough fermentation. New microbial metabolites, putatively identified as O-methylcatechol-vinyl-isoflavans, were detected in all fermented samples, with levels increasing with fermentation time. Based on structure, these compounds were likely derived from cell wall C-C linked diferulic acid metabolism. As expected, Folin reactive phenols and antioxidant capacity increased in fermented samples, but the extent was distinctly smaller in sorghums (1.3-1.9 fold) vs teff (2.4-3.2 fold) and wheat (2.0-6.1 fold), likely due to higher presence of easily metabolizable phenolics in sorghum. The phenolic profile of a cereal grain affects the products of microbial metabolism during fermentation, and may thus alter phenolic-dependent bioactive properties associated with a specific grain.

Effect of food processing on the antioxidant activity of flavones from Polygonatum odoratum (Mill.) Druce

Polygonatum odoratum (Mill.) Druce (POD) is a natural plant widely used for food and medicine, thanks to its rich content of a strong antioxidant agent called homoisoflavones. However, food processing methods could affect the stability of POD flavones, resulting in changes to their antioxidant activity. This study attempts to evaluate the antioxidant activity of POD flavones subject to different processing methods and determines which method could preserve the antioxidant activity of POD flavones. Therefore, flavones were extracted from POD samples, which had been treated separately with one of the four processing methods: extrusion, baking, high-pressure treatment, and yeast fermentation. After that, the antioxidant activity of the flavones was subject to in vivo tests in zebrafish embryos. The results show that yeast fermentation had the least disruption to the antioxidant activity of POD flavones, making it the most suitable food processing method for POD. By contrast, extrusion and high-pressure treatment both slightly weakened the antioxidant activity of the flavones and should be avoided in food processing. The research results provide a reference for the development and utilization of POD and the protection of its biological activity.

Recent Applications of Heteropolyacids and Related Compounds in Heterocycle Synthesis. Contributions between 2010 and 2020

Over the past two decades, polyoxometalates (POM) have received considerable attention as solid catalysts, due to their unique physicochemical characteristics, since, first, they have very strong Bronsted acidity, approaching the region of a superacid, and second, they are efficient oxidizers that exhibit rapid redox transformations under fairly mild conditions. Their structural mobility is also highlighted, since they are complex molecules that can be modified by changing their structure or the elements that compose them to model their size, charge density, redox potentials, acidity, and solubility. Finally, they can be used in substoichiometric amounts and reused without an appreciable loss of catalytic activity, all of which postulate them as versatile, economic and ecological catalysts. Therefore, in 2009, we wrote a review article highlighting the great variety of organic reactions, mainly in the area of the synthesis of bioactive heterocycles in which they can be used, and this new review completes that article with the contributions made in the same area for the period 2010 to 2020. The synthesized heterocycles to be covered include pyrimidines, pyridines, pyrroles, indoles, chromenes, xanthenes, pyrans, azlactones, azoles, diazines, azepines, flavones, and formylchromones, among others.