Distinct Flavonoid Research Articles

Total flavonoids from Rosa rugosa Thunb.: A comprehensive review of its extraction and purification process, chemical composition, biological effect and applications.

Rosa rugosa Thunb. is a kind of traditional Chinese medicine with homology of medicine and food in China for a long history. The total flavonoids from R. rugosa Thunb. (TFR), possessing antioxidant, anti-tumor, antidepressant, and antibacterial activities, can effectively prevent and treat cardiovascular, hyperglycemia, hyperlipidemia, and other diseases. However, few studies have focused on TFR analyses and no comprehensive review has yet been published. In order to provide a theoretical foundation and research direction for further study and development, this paper methodically reviewed the extraction and purification procedure, chemical composition, biological activity, toxicology, and application in food of TFR on the basis of previous research. A total of 102 distinct flavonoids have been isolated from R. rugosa Thunb. Further pharmacological activities and chemical analyses research will contribute to the development of TFR products in R. rugosa Thunb.

Enhanced antioxidant activities, polyphenols, flavonoids, and free amino acid contents of Nelumbo nucifera bee pollen via high hydrostatic pressure treatment

ABSTRACT The aim of the present study was to address the effect of high hydrostatic pressure (HHP) on bioactive compounds and antioxidant activity of Nelumbo nucifera (Lotus) bee pollen (LBP). The total phenolic contents (TPC) and free amino acids were determined and flavonoid composition was identified by UPLC-Triple-TOF-MS. Five analytical methods including DPPH, ABTS, reducing power, FRAP, and silver nanoparticles antioxidant capacity were used for the antioxidant activity analysis. The results revealed a significant increase in the TPC and free amino acid compositions after HHP treatment. The DPPH, ABTS, reducing power, FRAP, and AgNPAC of the extracted fractions were augmented by over 13.94, 2.9, 2.68, 85, and 2.6 times, respectively. PCA analysis showed a strong correlation between TPC, some distinct flavonoids, and antioxidant activities. These results indicated that HHP enhances the antioxidant activity of LBP via increase in amino acids, TPC, and some flavonoids such as Licoagrone, Kuwanon K, Cyanidin 3-rutinoside, etc.

A Novel Approach for Apical Periodontitis Prevention Through RIPK3 Inhibition Using Organic Flavonoids

Background: Apical periodontitis (AP) entails inflammatory bone resorption facilitated by the induction of necroptosis through receptor-interacting protein kinase 3 (RIPK3). Consequently, the inhibition of RIPK3 holds the potential for favorable effects in addressing AP. A comprehensive investigation, encompassing 44 flavonoids, was undertaken to identify potential inhibitors of RIPK3. Methods: The crystal structure of the RIPK3 catalytic domain (PDB ID: 7MON) underwent meticulous preparation through the removal of ligands and energy optimization. Overall, 44 flavonoids were examined in this study. Utilizing AutoDock 4.0, molecular docking analyses were performed to evaluate the binding energies within the active site of RIPK3 concerning the examined herbal isolates, with subsequent comparison to the results obtained from a positive control inhibitor. Furthermore, the BIOVIA Discovery Studio Visualizer played a crucial role in elucidating the interactions between the top-ranked flavonoids and the residues of RIPK3. Results: Five distinct flavonoids—orientin, rutin, vicenin-2, amentoflavone, and nicotiflorin—manifested notable inhibitory effects on RIPK3, boasting inhibition constant values at either the femtomolar or picomolar scale. Notably, the first three members of this set showcased superior binding affinity to the active site of RIPK3 compared to the reference compound. Conclusion: The proposition arises that flavonoid, particularly orientin, rutin, vicenin-2, amentoflavone, and nicotiflorin, stand as promising herbal isolates for the therapeutic management of AP.

Comparative Analysis of Citrus Species' Flavonoid Metabolism, Gene Expression Profiling, and Their Antioxidant Capacity under Drought Stress.

Citrus species are widely cultivated across the globe and frequently encounter drought stress during their growth and development phases. Previous research has indicated that citrus species synthesize flavonoids as a response mechanism to drought stress. This study aimed to comprehensively quantify and analyze the presence of 85 distinct flavonoids in the leaf and root tissues of lemon (drought susceptible) and sour orange (drought tolerant). In drought-stressed sour orange roots, flavonoids, such as isosakuranin, mangiferin, trilobatin, liquiritigenin, avicularin, silibinin, and glabridin, were more elevated than control sour orange roots and drought-stressed lemon roots. Additionally, hydroxysafflor yellow A, cynaroside, tiliroside, and apigenin 7-glucoside were increased in drought-stressed sour orange leaves compared to drought-stressed lemon leaves. Under drought stress, flavonoids such as (-)-epigallocatechin, silibinin, benzylideneacetophenone, trilobatin, isorhamnetin, 3,7,4'-trihydroxyflavone, and liquiritigenin were significantly increased, by 3.01-, 3.01-, 2.59-, 2.43-, 2.07-, 2.05-, and 2.01-fold, in sour orange roots compared to control sour orange roots. Moreover, the total flavonoid content and antioxidant capacity were significantly increased in drought-stressed sour orange leaves and root tissues compared to drought-stressed lemon leaves and root tissues. The expression levels of genes involved in flavonoid biosynthesis were highly expressed in sour orange leaves and roots, compared to lemon leaves and root tissues, post-drought stress. These findings indicate that lemons fail to synthesize protective flavonoids under drought conditions, whereas sour orange leaves and root tissues enhance flavonoid synthesis, with higher antioxidant activities to mitigate the adverse effects of reactive oxygen species generated during drought stress.

Investigating the Antioxidant Capacity of Newly Synthesized Flavonoids via DPPH Assay.

Numerous naturally occurring and artificially synthesized flavonoids have garnered attention for their impressive ability to combat oxidative stress and scavenge free radicals when evaluated in laboratory settings. The core aim of our investigation revolved around assessing the antioxidant potential of a diverse range of synthesized flavonoids through in vitro experiments. We crafted 29 distinct flavonoids using the aldol condensation mechanism via a chalcone intermediate to accomplish this. We meticulously characterized these newly formed compounds using a variety of spectroscopic techniques. We employed the widely recognized DPPH free radical method for the crucial antioxidant evaluation, a benchmark in such studies. The radical scavenging efficacy of our synthesized flavonoids was then meticulously compared to that of the positive control, ascorbic acid, renowned for its antioxidant prowess, and the IC50 values for each compound were calculated and examined. Surprisingly, our results showed that the flavonoids we tested had a wide range of antioxidant activity, with IC50 values that ranged from 75.8 ± 8.30 to 397 ± 25.10 μg/mL. Intriguingly, compounds US5, US13, US16, US17, US18, and US21 outshone even ascorbic acid in their antioxidant potential, displaying remarkable scavenging abilities against free radicals. This discovery holds promise for further exploration of these compounds as potential antioxidants with potential applications in health and wellness.

Exploring the Flavonoid Biosynthesis Pathway of Two Ecotypes of Leymus chinensis Using Transcriptomic and Metabolomic Analysis

This research investigates the flavonoid biosynthesis pathways of two ecotypes of Leymus chinensis, distinguished by their gray-green (GG) and yellow-green (YG) leaf colors, to uncover the molecular bases of their adaptability to different environmental conditions. By integrating comprehensive transcriptomic and metabolomic analyses, we identified 338 metabolites, with 161 showing differential expression—124 upregulated and 37 downregulated. The transcriptomic data revealed substantial variation, with 50,065 genes differentially expressed between the ecotypes, suggesting complex genetic regulation of the flavonoid biosynthesis pathways involving 20 enzyme-coding genes. KEGG pathway enrichment analysis further highlighted the involvement of 26 genes in the synthesis of four distinct types of flavonoid metabolites, indicating the sophisticated modulation of these pathways. Our results demonstrate that the GG and YG ecotypes of Leymus chinensis exhibit distinct flavonoid profiles and gene expression patterns, with the GG ecotype showing a higher accumulation of quercetin and kaempferol (increased by 25% and 33%, respectively, compared to YG), suggesting enhanced antioxidant capacity. Conversely, the YG ecotype displayed a broader spectrum of flavonoid metabolites, possibly indicating an adaptive strategy favoring diverse ecological interactions. Our results show that the GG and YG ecotypes of Leymus chinensis exhibit distinct flavonoid profiles and gene expression patterns, suggesting divergent adaptive strategies to environmental stress. This study highlights the crucial role of flavonoid metabolites in plant adaptation strategies, enhancing our understanding of plant resilience and adaptability. The distinct metabolic profiles observed suggest that the GG ecotype may be better equipped to handle oxidative stress, while the YG ecotype could be predisposed to broader ecological interactions. This emphasizes the value of applying machine learning in predicting plant adaptability, providing a new perspective for the future exploration of how plants adapt to environmental challenges. Meanwhile, the information gleaned from this nuanced study offers a foundation for future investigations into the genetic and environmental factors involved in plant adaptation.

Multi-omics landscape to decrypt the distinct flavonoid biosynthesis of Scutellaria baicalensis across multiple tissues.

Scutellaria baicalensis Georgi, also known as huang-qin in traditional Chinese medicine, is a widely used herbal remedy due to its anticancer, antivirus, and hepatoprotective properties. The S. baicalensis genome was sequenced many years ago; by contrast, the proteome as the executer of most biological processes of S. baicalensis in the aerial parts, as well as the secondary structure of the roots (xylem, phloem, and periderm), is far less comprehensively characterized. Here we attempt to depict the molecular landscape of the non-model plant S. baicalensis through a multi-omics approach, with the goal of constructing a highly informative and valuable reference dataset. Furthermore, we provide an in-depth characterization dissection to explain the two distinct flavonoid biosynthesis pathways that exist in the aerial parts and root, at the protein and phosphorylated protein levels. Our study provides detailed spatial proteomic and phosphoproteomic information in the context of secondary structures, with implications for the molecular profiling of secondary metabolite biosynthesis in non-model medicinal plants.

Uncovering nutritional metabolites and candidate genes involved in flavonoid metabolism in Houttuynia cordata through combined metabolomic and transcriptomic analyses

The perennial herb Houttuynia cordata has long been cultivated and used as medicinal and edible plant in Asia. Nowadays, increasing attention is attracted due to its numerous health benefits. Flavonoids are the main chemical constituents exerting pharmacological activities. In the present study, we investigated both metabolome and transcriptome of two H. cordata accessions (6# and 7#) with distinct flavonoids contents. In total 397 metabolites, i.e., 220 flavonoids, 92 amino acids and derivatives, 20 vitamins, and 65 saccharides were abundant in aboveground part. Cyanidin-3-O-rutinoside and quercetin-3-O-galactoside were the most abundant flavonoids, which can be categorized into seven classes, namely anthocyanidins, chalcones, flavanols, flavanones, flavanonols, flavones, and flavonols. Flavonols was the most abundant group. Contents of 112 flavonoids differed significantly between the two accessions, with catechin-(7,8-bc)-4α-(3,4-dihydroxyphenyl)-dihydro-2-(3H)-one, cinchonain Id, and cinchonain Ic being the dominant flavonoid metabolites among them. Pinocembrin-7-O-neohesperidoside, pinocembrin-7-O-rutinoside, and kaempferol-3-O-galactoside-4′-O-glucoside were uniquely abundant in accession 7. Transcriptome data revealed a total of 110 different expressed genes related to flavonoid metabolism, with more highly expressed genes observed in 7#. We annotated a total of 19 differential flavonoid metabolites and 34 differentially expressed genes that are associated with the flavonoid metabolic network. Based on the transcriptome and qPCR data a total of 8 key candidate genes involved in flavonoid metabolism were identified. The ANS gene were found to play an important role in the synthesis of cyanidin-3-O-glucoside, while the CHI, F3′H and FLS genes were mainly responsible for controlling the levels of flavanones, flavones, and flavonols, respectively. Collectively, the present study provides important insights into the molecular mechanism underlying flavonoid metabolism in H. cordata.

Standardized extract of Ginkgo biloba enhances memory persistence over time

BackgroundPreviously, our group has shown that treatment with a standardized extract of Ginkgo biloba leaves (EGb) before acquisition/encoding of the conditioned suppression and object recognition task produced recent memory persistence by upregulating CREB-1 and BDNF in the hippocampal formation in a dose-dependent manner. Moreover, memory durability is influenced by processes that occur after encoding. Since the effects of EGb on consolidation processes and memory persistence are unknown, the characterization of these effects will help elucidate both the beneficial and harmful effects of “cognitive enhancers” treatments. MethodsWe investigated the effects of EGb treatment (250, 500 and 1000 mg Kg−1) on consolidation of conditioned lick suppression memory and its persistence, i.e., assessing fear memory retrieval and extinction, 2–4 days (recent long-term memory) or 40–42 days (remote long-term memory) after its acquisition. We also analyzed the compounds in the EGb by UHPLC-HRMS/MS and molecular networking (MN) for dereplication. ResultsWe show, for the first time, that EGb-induced persistence of conditioned suppression. Interestingly, while a higher dose promoted both recent and remote long-term memory persistence without preventing the acquisition of fear extinction memory, the lower dose induced the persistence of original fear remote memory and prevented extinction fear memory formation. The intermediate dose seems to be related to anti-anxiety effects. Furthermore, dereplication of EGb assisted by GNPS detected, besides ginkgolides A, B and D, distinct flavonoids, including quercetin, rutin and nicotiflorin. ConclusionThis study is the first to show that EGb treatment modulates recent and remote fear memory consolidation and its persistence. Additionally, our phytochemical analysis of the EGb corroborates the presence of flavonoids and terpenoids, which may account for the biological effects of EGb on the duration of memory and shed light on its potential as an adjunct to the treatment of memory decline or anxiety disorders.

Biochemical Characterization of Black and Green Mutant Elderberry during Fruit Ripening.

The content of sugars, organic acids, phenolic compounds and selected enzyme activities in the anthocyanin pathway were analyzed in NIGRA (Sambucus nigra var. nigra-black fruits) and VIRIDIS (S. nigra var. viridis-green fruits) fruits over four stages of ripening. The share of glucose and fructose in green fruits was higher than in colored fruits, and the sugar content increased significantly until the third developmental stage. Ripe NIGRA berries had 47% flavonol glycosides, 34% anthocyanins, 3% hydroxycinnamic acids and 14% flavanols, whereas the major phenolic group in the VIRIDIS fruits, making up 88% of the total analyzed polyphenols, was flavonols. NIGRA fruits were rich in anthocyanins (6020 µg g-1 FW), showing strong activation of the late anthocyanin pathway (dihydroflavonol 4-reductase, anthocyanidin synthase). In both color types, phenylalanine ammonia lyase and chalcone synthase/chalcone isomerase activities were highest in the first stage and decreased during ripening. In VIRIDIS fruit, no anthocyanins and only one flavanol (procyanidin dimer) were found. This was most likely caused by a lack of induction of the late anthocyanin pathway in the last period of fruit ripening. The VIRIDIS genotype may be useful in studying the regulatory structures of anthocyanin biosynthesis and the contribution of distinct flavonoid classes to the health benefits of elderberries.

Kaempferitrin: A Flavonoid Marker to Distinguish Camellia oleifera Honey.

C. oleifera is an economically important oilseed crop and medical plant. However, as a characteristic honey resource, the standard protocol used to identify the composition of C. oleifera honey has not been established yet. Previously, distinctive flavonoid has been shown as an effective marker to trace the botanical origin of honey. In this study, we examined the flavonoid types in C. oleifera honey and nine other monofloral honeys by using liquid chromatography tandem-mass spectrometry (LC-MS/MS) and compared the differences and identified eight distinct flavonoids in C. oleifera honey. Then, comparing the 8 flavonoids with the 14 flavonoids common to C. oleifera honey and nectar, two distinct flavonoids were identified in C. oleifera honey and nectar. Finally, we identified kaempferitrin as the distinct flavonoid marker in C. oleifera honey using the degree of influence of the partial least-squares discriminant analysis (PLS-DA) model on C. oleifera honey and ployfloral honey.

Inhibition of the predicted allosteric site of the SARS-CoV-2 main protease through flavonoids

Since its emergence in 2019, coronavirus infection (COVID-19) has become a global pandemic and killed several million people worldwide. Even though several types of vaccines are available against the COVID-19 virus, SARS-CoV-2, new strains are emerging that pose a constant danger to vaccine effectiveness. In this computational study, we identified and predicted potent allosteric inhibitors of the SARS-CoV-2 main protease (Mpro). Via molecular docking and simulations, more than 100 distinct flavonoids were docked with the allosteric site of Mpro. Docking experiments revealed four top hit compounds (Hesperidin, Schaftoside, Brickellin, and Marein) that bound strongly to the Mpro predicted allosteric site. Simulation analyses further revealed that these continually interacted with the enzyme’s allosteric region throughout the simulation time. ADMET and Lipinski drug likenesses were calculated to indicate the therapeutic value of the top four hits: They were non-toxic and exhibited high human intestinal absorption concentrations. These novel allosteric site inhibitors provide a higher chance of drugging SARS-CoV2 Mpro due to the rapid mutation rate of the viral enzyme’s active sites. Our findings provide a new avenue for developing novel allosteric inhibitors of SARS-CoV-2 Mpro. Communicated by Ramaswamy H. Sarma

Comprehensive transcriptomic and metabolomic analysis revealed distinct flavonoid biosynthesis regulation during abnormal pistil development in Japanese apricot

Japanese apricot is an imperative stone fruit plant with numerous processing importance. The failure of reproductive system is the most common cause of fruit loss, through which pistil abortion is the fundamental one. To understand this mechanism, we used a combination of transcriptomic and metabolomic approaches to investigate the biochemical and molecular basis of flavonoid biosynthesis. Due to the regulated expression of flavonoid pathway-related genes in plants, flavonoid biosynthesis is largely regulated at the transcriptional level. A total of 2272 differently expressed genes and 215 differential metabolites were found. The expression of the genes and metabolites encoding flavonoid biosynthesis was lower in abnormal pistils that are in line with the flavonoid quantification from abnormal pistils. Besides, a couple of genes were also detected related to MYB, MADS, NAC and bHLH transcription factors. Remarkably, we found ‘hydroxycinnamoyl transferase (LOC103323133)’ and flavonoid related metabolite ‘2-hydroxycinnamic acid’ was lower expressed in abnormal pistil, proposing the cause of pistil abortion. Collectively, the present study delivers inclusive transcriptional and metabolic datasets that proposed valuable prospects to unravel the genetic mechanism underlying pistil abortion.

FLAVONES AND THEIR DERIVATIVES: SYNTHETIC AND PHARMACOLOGICAL IMPORTANCE

Flavones (from the Latin flavus, which means “yellow”) are a kind of flavonoid with a backbone of 2-phenylchromen-4-one. Flavones, one of the most important classes of plant secondary metabolites, are well-known for their anti-cancer, anti-inflammatory, anti-microbial, antioxidant, anti-osteoporatic, anti-diabetic, anti-estrogenic, anti-allergic, and metal chelating properties. These family compounds have been intensively studied synthetically due to their wide spectrum of biological actions, and more than 4000 chemically distinct flavonoids have been identified from plants. However, new advances in synthetic chemistry have resulted in the production of a number of therapeutically important derivatives. This article summarizes the synthesis of flavones, their derivatives, and other flavone analogues which have the potential for treating a range of illnesses and ailments.

Response surface methodology-optimized extraction of flavonoids with antioxidant and antimicrobial activities from the exocarp of three genera of coconut and characterization by HPLC-IT-TOF-MS/MS

Response surface methodology optimization based on central composite design was applied to extract flavonoids from the exocarp of three coconut genera. The antioxidant and antimicrobial activities and structures of the flavonoids were determined. The results indicated that the optimal extraction conditions were ethanol concentration, 60%; temperature, 50 ℃; time, 90 min; liquid/material ratio, 40 mL/g; ultrasonic power, 150 W. Under these conditions, the yields of green, red and yellow coconut exocarp were 366.03 ± 7.57, 596.38 ± 10.32, and 403.78 ± 5.56 mg rutin/g powder, respectively. The flavonoids exhibited eminent DPPH and ABTS radical scavenging activities with IC50 values of 0.01–0.02 mg/mL. At a concentration of 2 mg/mL, they exhibited antimicrobial activity against Vibrio parahaemolyticus, Listeria monocytogenes, Escherichia coli, Staphylococcus aureus, Salmonella and Pseudomonas aeruginosa. In total, 17 flavonoids and 5 phenolic acids were characterized by UPLC-IT-TOF-MS/MS; among them, catechin, kaempferol, and quercetin were abundant. Yellow coconut had a distinct flavonoid spectrogram from other genera and contained more methoxy flavonoids.

Seasonal variation of phenolic compounds in Zostera marina (Zosteraceae) from the Baltic Sea

Seasonal variations of phenolic compounds, in leaves of Zostera marina L. from the Baltic Sea near Kiel/Germany were investigated. Dominant compounds were mono- and disulfated flavonoids and phenylpropanoic acids, in particular luteolin 7,3ʹ-O-disulfate and diosmetin 7-O-sulfate as well as rosmarinic acid, a dimeric phenylpropanoid. All detected sulfated flavones showed similar seasonal trends: there were two significant concentration peaks in June and November. Moreover, two geographically distinct flavonoid chemotypes were identified based on their respective main flavonoid; one chemotype was characterized by the prevalence of luteolin 7,3ʹ-O-disulfate (German Baltic Sea), and the other by the prevalence of diosmetin 7-O-sulfate (Norwegian North Sea). Furthermore, an undescribed tetrameric phenylpropanoid, 7ʹʹ,8ʹʹ-didehydrosalvianolic acid B, was isolated and its structure was established by extensive NMR, MS, and CD experiments. This compound inhibited activity of Na+/K+-ATPase in the micro-molar range without any cytotoxic effects against human cancer and normal cells.

Comparative metabolomics analysis revealed biomarkers and distinct flavonoid biosynthesis regulation in Chrysanthemum mongolicum and C. rhombifolium.

Chrysanthemums are traditional flowers that originated in China and have high ornamental, economic and medicinal value. They are widely used as herbal remedies and consumed as food or beverages in folk medicine. However, little is known about their metabolic composition. The aims of this work were to determine the metabolic composition of and natural variation among different species of Chrysanthemum and to explore new potential resources for drug discovery and sustainable utilisation of wild Chrysanthemum. The metabolomes of Chrysanthemum mongolicum (Ling) Tzvel. and Chrysanthemum rhombifolium H. Ohashi & Yonek. were compared using a widely targeted metabolomics approach based on liquid chromatography-tandem mass spectrometry (LC-MS/MS). In total, 477 metabolites were identified, of which 72 showed significant differences in expression between C. mongolicum and C. rhombifolium, mainly in flavonoids, organic acids and nucleotides. The flavone and flavonol biosynthesis pathway showed significant enrichment among the differentially expressed metabolites. The contents of genkwanin, trigonelline, diosmin, narcissoside, 3,4-dihydroxyphenylacetic acid, linarin, N',N'-p-coumarin, C-hexosyl-tricetin O-pentoside, chrysoeriol, acacetin and kaempferol-3-O-gentiobioside were significantly different between the two species and represent potential biomarkers. The types of flavonoid-related metabolites in the flavonoid biosynthesis pathway differed between C. mongolicum and C. rhombifolium. The mechanisms underlying the unique adaptations of these two species to their environments may involve variations in the composition and abundance of flavonoids, organic acids, and nucleotides. These methods are promising to identify functional compounds in Chrysanthemum species and can provide potential resources for drug discovery and the sustainable utilisation of Chrysanthemum plants.

Transcriptomic and metabolomic joint analysis reveals distinct flavonoid biosynthesis regulation for variegated testa color development in peanut (Arachis hypogaea L.)

Peanut is one of the important oil and economic crops, among which the variegated testa peanut is a unique member. The molecular mechanisms underlying the pigment synthesis in variegated testa are still unclear. Differentially expressed genes (DEGs) in the flavonoid metabolism pathway in pigmented areas indicated that there were 27 DEGs highly related to the synthesis of variegated testa color among 1,050 DEGs. Of these 27, 13 were up-regulated and 14 were down-regulated, including 3 PALs, 1 C4H, 2 CHSs, 1 F3H, 1 F3'H, 2 DFRs, 2 LARs, 2 IAAs, 4 bHLHs, and 9 MYBs. GO (Gene Ontology) analysis indicated that DEGs were similarly enriched in three branches. KEGG (Kyoto Encyclopedia of Genes and Genomes) analysis suggested flavonoid biosynthesis is the most direct metabolic pathway for the synthesis of testa variegation. The liquid chromatography–tandem mass spectrometry (LC–MS/MS) results showed that cyanidin and delphinidin were the primary metabolites that caused the color differences between the pigmented and the non-pigmented areas. Through the verification of 20 DEGs via qPCR, the results were consistent with transcriptome sequencing in four comparison groups. The results in this study lay the foundation for revealing the molecular regulation mechanisms of flavonoid synthesis in variegated testa peanut.

Study on the change of flavonoid glycosides to aglycones during the process of steamed bread containing tartary buckwheat flour and antioxidant, α-glucosidase inhibitory activities evaluation in vitro

Tartary buckwheat dough (120 g) was used to produce steamed tartary buckwheat bread (STB). Alterations in antioxidant capacity and α-glucosidase inhibitory activity levels, and the concentrations of various flavonoid compounds, were investigated after each processing stage. It was identified that aglycone (quercetin and kaempferol) levels were increased after dough formation and fermentation stages. These stages were also associated with higher antioxidant capacity and α-glucosidase inhibitory activity. After steaming, flavonoid compound and antioxidant activity levels were slightly decreased in comparison to those observed after dough formation and fermentation steps, although they were higher than in raw flour.To clarify the anti-diabetic potential of individual flavonoid compounds, the antioxidant and α-glucosidase inhibitory activities of four distinct flavonoids were investigated. The results of the present study revealed that aglycones have more potent anti-diabetic effects than their corresponding glycosides, which may explain the change in antioxidant and α-glucosidase inhibitory activities of samples taken after the different processing stages. Correlation analysis also indicated that flavonoids’ being in their aglycone form was positively associated with higher antioxidant and α-glucosidase inhibitory activities. Overall, these data suggest that deglycosylation of flavonoids, which occurs during the preparation of STB, contributes to higher hypoglycemic potential in tartary buckwheat bread products.

Hypericum triquetrifolium and H. neurocalycinum as Sources of Antioxidants and Multi-Target Bioactive Compounds: A Comprehensive Characterization Combining In Vitro Bioassays and Integrated NMR and LC-MS Characterization by Using a Multivariate Approach.

Hypericum triquetrifolium and H. neurocalycinum were evaluated for their phytochemical content and in vitro bioactivity. NMR analyses were performed on the methanol extract of the aerial parts of H. triquetrifolium to establish the main classes of phytoconstituents. Then, LC-DAD-MSn analyses were performed in order to compare the composition of aerial parts and roots extracts of both Hypericum species, obtained using either methanol or water as solvents. Results, processed using multivariate data analysis, showed a significantly higher phenolic content of methanol extracts compared to water extracts, while minor qualitative differences were observed between the two. Distinctive flavonoid and PAC patterns were observed for H. triquetrifolium and H. neurocalycinum, and specific compounds were exclusively detected in one or the other species. Specifically, the phloroglucinols 7-epiclusianone, hyperfirin and hyperforin were present only in H. neurocalycinum, while hyperforin was detected only in H. triquetrifolium. Extracts were assayed using different in vitro tests to evaluate their antioxidant properties and their inhibitory activity against several enzymes, showing significant antioxidant and metal chelating activities. Furthermore, inhibitory properties against acetylcholinesterase, butyrylcholinesterase and tyrosinase were observed. Multivariate approaches were used to correlate biological data with the phytochemical composition of the different extracts. The results, showing positive correlations between specific chemical constituents and the measured bioactivities, represent preliminary data that could guide future studies aimed at isolating bioactive constituents from H. neurocalycinum and H. triquetrifolium for further pharmacological evaluations.