Flavone Content Research Articles

Comparative analysis of volatile compounds and functional components in fresh and dried monk fruit (Siraitia grosvenorii)

Monk fruit (Siraitia grosvenorii) is a medicinal and edible plant that is often used to prepare tea and alleviate coughs in China. Most of the S. grosvenorii available on the market is dried. However, the drying process affects the composition and content of the chemical components in the plants. To date, there have been few studies that have compared the chemical composition in fresh and dried S. grosvenorii. The chemical composition of fresh and dried plant tissue was analyzed using gas chromatography-mass spectrometry, high-performance liquid chromatography, and spectrophotometry, and their statistical differences were compared. The effect of altitude on the chemical composition of S. grosvenorii was also studied. The volatile compounds in both fresh and dried S. grosvenorii primarily consisted of alkanes, alkenes, organic acids, and aldehydes, which accounted for 93.62 % and 87.64 % of the volatiles in fresh and dried S. grosvenorii tissues, respectively. The most abundant volatile compound was n-hexadecanoic acid (fresh: 31.73 %, dried: 37.49 %). After hot air drying, the contents of alkanes, alkenes, esters, and alcohols increased by 5.76 %, 2.68 %, 2.35 %, and 2.96 %, respectively, whereas the contents of aldehydes decreased by 13.94 %. Compared with fresh S. grosvenorii, the levels of mogroside V, vitamin C, protein, fructose, and glucose in the dried tissue of this plant decreased significantly by 13.13 %, 100.0 %, 46.31 %, 40.39 %, and 75.07 %, respectively, while the contents of total phenolics, total flavones, total flavonols, and sucrose increased significantly by 144.9 %, 84.94 %,142.1 %, and 128.0 %, respectively. The contents of fructose and glucose significantly positively correlated with altitude.

Antioxidant Benefits and Potential Mechanisms of Slightly Acidic Electrolyzed Water Germination in Sesame.

Slightly acidic electrolytic water (SAEW) treatment for seed germination is a promising technique for sustainable agriculture. This study investigated the antioxidant activity of germinated sesame seeds treated with SAEW for the first time. Specifically, the impact and correlation of SAEW on the activities of total phenols, total flavonoids, and antioxidant oxidase in sesame seeds were examined. The results showed that SAEW with low ACC inhibited sesame germination, SAEW with high ACC promoted sesame germination, and sesame buds treated with SAEW with 30 mg/L and 50 mg/L ACC showed lower antioxidant activity and total phenolic and flavone content compared to tap water. In contrast, SAEW with 30 mg/L ACC had no significant effect on sesame growth but positively influenced the antioxidant activity of sesame seed germination by promoting phenolic compound synthesis through increased phenylalanine ammonia-lyase (PAL) activity and enhancing antioxidant activity by boosting PAL, polyphenol oxidase (PPO), and peroxidase (POD) activities. Generally, antioxidant ability was the most prominent in SAEW with 30 mg/L ACC, and positive correlations between antioxidation and total phenols and flavonoids content were found in sesame. These findings provide valuable insights into the mechanisms underlying the enhanced antioxidant capacity observed in germinated sesame seeds under SAEW stress.

In Vitro Assessment of the Antidiabetic and Anti-Inflammatory Potential of Artemisia absinthium, Artemisia vulgaris and Trigonella foenum-graecum Extracts Processed Using Membrane Technologies.

Recently, there has been increased interest in the discovery of new natural herbal remedies for treating diabetes and inflammatory diseases. In this context, this work analyzed the antidiabetic and anti-inflammatory potential of Artemisia absinthium, Artemisia vulgaris and Trigonella foenum-graecum herbs, which have been studied less from this point of view. Therefore, extracts were prepared and processed using membrane technologies, micro- and ultrafiltration, to concentrate the biologically active principles. The polyphenol and flavone contents in the extracts were analyzed. The qualitative analysis of the polyphenolic compounds was performed via HPLC, identifying chlorogenic acid, rosmarinic acid and rutin in A. absinthium; chlorogenic acid, luteolin and rutin in A. vulgaris; and genistin in T. foenum-graecum. The antidiabetic activity of the extracts was analyzed by testing their ability to inhibit α-amylase and α-glucosidase, and the anti-inflammatory activity was analyzed by testing their ability to inhibit hyaluronidase and lipoxygenase. Thus, the concentrated extracts of T. foenum-graecum showed high inhibitory activity on a-amylase-IC50 = 3.22 ± 0.3 μg/mL-(compared with acarbose-IC50 = 3.5 ± 0.18 μg/mL) and high inhibitory activity on LOX-IC50 = 19.69 ± 0.52 μg/mL (compared with all standards used). The concentrated extract of A. vulgaris showed increased α-amylase inhibition activity-IC50 = 8.57 ± 2.31 μg/mL-compared to acarbose IC50 = 3.5 ± 0.18 μg/mL. The concentrated extract of A. absinthium showed pronounced LOX inhibition activity-IC50 = 19.71 ± 0.79 μg/mL-compared to ibuprofen-IC50 = 20.19 ± 1.25 μg/mL.

Integrated analysis of multiple metabolome and transcriptome revealed the accumulation of flavonoids and associated molecular regulation mechanisms in Rubus chingii Hu at different developmental stages

The traditional Chinese herb Rubus chingii Hu (R. chingii) is widely used in clinical practice due to its beneficial effects. Flavonoids are the important class of pharmacological substances in R. chingii, however, the molecular mechanism underlying the differences in active flavonoid contents in R. chingii at different developmental stages remain poorly understood. In this experiment, we selected four developmental stages (GG, GY, YR, RR) of R. chingii as the research material. We studied the untargeted and targeted metabolic profiles of flavonoids in different periods of R. chingii, combining full-length and comparative transcriptome analyses. Functional analyses were conducted on genes implicated in flavonoid differences. GG and RR displayed relatively higher and lower contents of flavonols, flavones, flavanols, flavanones, and isoflavonoid, respectively. RNA-seq analyses showed structural genes such as RcPAL, RcC4H, Rc4CL, RcCHS, RcCHI, RcF3H, RcF3′H, and RcFLS in flavonoid biosynthesis pathway were upregulated in GG, which were essential for the accumulation flavanones, flavones, and flavonols (effective components). qRT-PCR analyses investigated that six structural genes RcCHI, RcF3H, 2 RcCHS, and 2 Rc4CL, two TFs RcMYB308 and RcMYB123 had a consistent expression pattern with which in transcriptome. Also, an interaction network showed that the RcMYB308 could positively regulate Ka3R, Qu, Qu3G, AS, Hy, Ti through RcF3H. Furthermore, Subcellular localization analysis revealed that RcMYB308 was localization to the nucleus. In tobacco, RcMYB308 was overexpressed, resulting in higher flavonoids, RcF3H, RcF3′H, RcCHI, and RcFLS. RcMYB308 upregulated RcF3H in dual-luciferase assays. These results provide new insights for further understanding the molecular mechanism regulating flavonol biosynthesis in R. chingii fruit, and also provide a potential MYB regulator for molecular breeding of R. chingii.

Determination of Phytochemical Contents in Extracts from Different Growth Stages of Oroxylum indicum Fruits Using HPLC-DAD and QAMS Methods.

Flavones are major compounds found in several parts of Oroxylum indicum (O. indicum). The quantification of multiple components by one marker (QAMS) method and the high-performance liquid chromatography (HPLC) method were developed for the quantitative analysis of extracts from the young fruits, green mature fruits, dry pod coats and seeds of O. indicum. Oroxin A, oroxin B and chrysin-7-O-glucuronide were identified in the O. indicum extracts. Oroxylin A and 5-hydroxymethylfurfural were isolated and structurally identified from the pod coat and young fruit extracts, respectively. From the HPLC analysis of the seven major flavones in the extracts, baicalin was the major compound in all extracts investigated (0.4-11% w/w of the extract). All flavone contents were low in the young fruit extract (<1% w/w of the extract). The green mature fruit and dry pod coat extracts showed similar constituent compositions. They contained small amounts of baicalin and oroxylin A, which were found only in these two extracts. Oroxylin A could be used as a marker to indicate the maturity of O. indicum fruits, while 5-hydroxymethylfurfural could be used as a marker for the young fruits. Baicalin was found to be a suitable single marker to calculate the contents of all flavones in the O. indicum extracts.

Succession of endophytic fungi and rhizosphere soil fungi and their correlation with secondary metabolites in Fagopyrum dibotrys.

Golden buckwheat (Fagopyrum dibotrys, also known as F. acutatum) is a traditional edible herbal medicinal plant with a large number of secondary metabolites and is considered to be a source of therapeutic compounds. Different ecological environments have a significant impact on their compound content and medicinal effects. However, little is known about the interactions between soil physicochemical properties, the rhizosphere, endophytic fungal communities, and secondary metabolites in F. dibotrys. In this study, the rhizosphere soil and endophytic fungal communities of F. dibotrys in five different ecological regions in China were identified based on high-throughput sequencing methods. The correlations between soil physicochemical properties, active components (total saponins, total flavonoids, proanthocyanidin, and epicatechin), and endophytic and rhizosphere soil fungi of F. dibotrys were analyzed. The results showed that soil pH, soil N, OM, and P were significantly correlated with the active components of F. dibotrys. Among them, epicatechin, proanthocyanidin, and total saponins were significantly positively correlated with soil pH, while proanthocyanidin content was significantly positively correlated with STN, SAN, and OM in soil, and total flavone content was significantly positively correlated with P in soil. In soil microbes, Mortierella, Trechispora, Exophiala, Ascomycota_unclassified, Auricularia, Plectosphaerella, Mycena, Fungi_unclassified, Agaricomycetes_unclassified, Coprinellus, and Pseudaleuria were significantly related to key secondary metabolites of F. dibotrys. Diaporthe and Meripilaceae_unclassified were significantly related to key secondary metabolites in the rhizome. This study presents a new opportunity to deeply understand soil-plant-fungal symbioses and secondary metabolites in F. dibotrys, as well as provides a scientific basis for using biological fertilization strategies to improve the quality of F. dibotrys.

Characterization Variation of the Differential Coloring Substances in Rapeseed Petals with Different Colors Using UPLC-HESI-MS/MS.

Rapeseed's (Brassica napus L.) colorful petals have important ornamental values. However, the mechanisms of regulating petals coloration in rapeseed are still unknown. In our study, we investigated the key differential coloring substances in nine rapeseed cultivars with different petal colors, and 543 metabolites were detected and characterized through UPLC-HESI-MS/MS. Among them, the kinds and contents of flavonols, flavones, and anthocyanidins were the main contributors to petals' coloration. Tamarixetin-, quercetin-, butin-, naringenin- and luteolin-derivates were the main pigment bases in white and yellow petals. Peonidin-3,5-O-diglucoside, peonidin-3-O-(6″-O-caffeoyl)glucoside, and quercetin-derivatives were the main coloring substances in pink petals. Acylated cyanidin derivatives might lead to a series of different purple petal colors. Glycosylated anthocyanins were responsible for the coloration of rapeseed red petals, and peonidin-3-O-glucoside and kaempferol-derivatives were mainly detected from the red petals. These results provide comprehensive insights into the difference in flavonoid metabolites in rapeseed petals with different colors and supply theoretical supports for the breeding of novel colorful rapeseed cultivars.

Fermentation improves flavors, bioactive substances, and antioxidant capacity of Bian-Que Triple-Bean Soup by lactic acid bacteria.

The ancient traditional Chinese drink Bian-Que Triple-Bean Soup made by fermentation (FTBS) of Lactococcus lactis subsp. lactis YM313 and Lacticaseibacillus casei YQ336 is a potential functional drink. The effect of fermentation on the flavor and biological activity of FTBS was evaluated by analyzing its chemical composition. Five volatile flavors were detected in modified FTBS. Fermentation decreased the proportion of nonanal (beany flavor substances) but significantly increased the total flavone contents, phenol contents and many bioactive small molecule substances in FTBS. The changes of these substances led to the significant improvement of FTBS sensory evaluation, antioxidant activity and prebiotic potential. This research provides a theoretical basis for the application of Lactic acid bacteria (LAB) in the fermentation of edible plant-based foods and transformation from traditional food to industrial production.

Metabolic Characteristics of Hairy Root Clones of Scutellaria pycnoclada and Scutellaria baicalensis

Scutellaria baicalensis is the most studied species of the genus, while Scutellaria pycnoclada is a poorly studied endemic species. Ten lines of the hairy roots of S. pycnoclada were obtained using Agrobacterium rhizogenes A4. The hairy root cultures of S. pycnoclada and the previously obtained roots of S. baicalensis were cultured on liquid and agar Gamborg media. A total of 14 flavonoids were detected via HPLC MS/MS in S. pycnoclada, and 17 were detected in S. baicalensis. Among them were flavones characteristic of both the roots and the aboveground parts of the plants. S. pycnoclada had a lower diversity of methylated flavones than S. baicalensis. Moreover, tenaxin I was absent in all S. pycnoclada lines on agar medium. HPLC analysis revealed that the flavone content in the different hairy root lines was 1.4–12.7 times higher on liquid medium than on agar medium. S. baicalensis and S. pycnoclada differed significantly in the ratio of the main flavones. In S. baicalensis, baicalin (7.83 mg/g DW) and wogonoside (6.29 mg/g DW) dominated when cultured on liquid medium, and wogonin (2.08 mg/g DW) dominated when cultured on solid medium. In S. pycnoclada, baicalin predominated (52–88% of the total content). S. pycnoclada is assumed to have a different set of O-methyltransferases and less biosynthetic enzyme activity than S. baicalensis.

Untargeted-based metabolomics analysis and in vitro/in silico antiviral activity of extracts from Phyllanthus brasiliensis (Aubl.) Poir.

This study describes the molecular profile and the potential antiviral activity of extracts from Phyllanthus brasiliensis, a plant widely found in the Brazilian Amazon. The research aims to shed light on the potential use of this species as a natural antiviral agent. The extracts were analysed using liquid chromatography-mass spectrometry (LC-MS) system, a potent analytical technique to discover drug candidates. In the meantime, in vitro antiviral assays were performed against Mayaro, Oropouche, Chikungunya, and Zika viruses. In addition, the antiviral activity of annotated compounds was predicted by in silico methods. Overall, 44 compounds were annotated in this study. The results revealed that P. brasiliensis has a high content of fatty acids, flavones, flavan-3-ols, and lignans. Furthermore, in vitro assays revealed potent antiviral activity against different arboviruses, especially lignan-rich extracts against Zika virus (ZIKV), as follows: methanolic extract from bark (MEB) [effective concentration for 50% of the cells (EC50 ) = 0.80 μg/mL, selectivity index (SI) = 377.59], methanolic extract from the leaf (MEL) (EC50 = 0.84 μg/mL, SI = 297.62), and hydroalcoholic extract from the leaf (HEL) (EC50 = 1.36 μg/mL, SI = 735.29). These results were supported by interesting in silico prediction, where tuberculatin (a lignan) showed a high antiviral activity score. Phyllanthus brasiliensis extracts contain metabolites that could be a new kick-off point for the discovery of candidates for antiviral drug development, with lignans becoming a promising trend for further virology research.

Development of a Comprehensive Quality Evaluation System for Foxtail Millet from Different Ecological Regions.

Foxtail millet (Setaria italica L.) is a critical grain with high nutritional value and the potential for increased production in arid and semiarid regions. The foxtail millet value chain can be upgraded only by ensuring its comprehensive quality. Thus, samples were collected from different production areas in Shanxi province, China, and compared in terms of quality traits. We established a quality evaluation system utilizing multivariate statistical analysis. The results showed that the appearance, nutritional content, and culinary value of foxtail millet produced in different ecological regions varied substantially. Different values of amino acids (DVAACs), alkali digestion values (ADVs), and total flavone content (TFC) had the highest coefficients of variation (CVs) of 50.30%, 39.75%, and 35.39%, respectively. Based on this, a comprehensive quality evaluation system for foxtail millet was established, and the quality of foxtail millet produced in the five production areas was ranked in order from highest to lowest: Dingxiang > Zezhou > Qinxian > Xingxian > Yuci. In conclusion, the ecological conditions of Xinding Basin are favorable for ensuring the comprehensive quality of foxtail millet. .

Comparative analysis of metabolite profiling and free radical scavenging activity in phenotypic variants of OsCOP1 colored rice mutant seed

Interest in colored rice has been increasing due to its health benefits. This study examined the metabolite profiling of CONSTITUTIVELY PHOTOMORPHOGENIC 1 (COP1) mutated rice seed (yel-mutant). The wild-type (WT) and the yel-mutant having yellow (y)- and purple (p)-pericarp variants from Chucheong (cc) and Samkwang (sk) cultivars were investigated for differences in bioactive metabolite profiles and free radical scavenging activity. The total fatty acid content decreased by >50% in the yel-mutant against the WT, while no significant difference was observed between yellow- and purple-pericarp variants (p < 0.05). The yel-mutant of both cultivars showed significantly higher flavone contents than their WT (non-detected). Most of the metabolites examined were highly produced in the yel-cc-p and the yel-sk-y than in the other phenotypic variants studied. This study provides further useful information for colored rice breeding by revealing the detailed biofunctional metabolic profile under COP1 mutation in colored rice.

Impact of Fermentation Conditions on Physicochemical Properties, Antioxidant Activity, and Sensory Properties of Apple-Tomato Pulp.

The aim of the study was to optimize the conditions [inoculum size (4, 6, and 8%), fermentation temperature (31, 34, and 37 °C), and apple: tomato ratio (2:1, 1:1, and 1:2)] on the viable cell count and sensory evaluation in apple-tomato pulp by response surface methodology (RSM), and determine the physicochemical properties, antioxidant activity, and sensory properties during fermentation. The optimal treatment parameters obtained were an inoculum size of 6.5%, a temperature of 34.5 °C, and an apple: tomato ratio of 1:1. After fermentation, the viable cell count reached 9.02 lg(CFU/mL), and the sensory evaluation score was 32.50. During the fermentation period, the pH value, total sugar, and reducing sugar decreased by 16.67%, 17.15%, and 36.05%, respectively. However, the total titratable acid (TTA), viable cell count, total phenol content (TPC), and total flavone content (TFC) increased significantly by 13.64%, 9.04%, 21.28%, and 22.22%, respectively. The antioxidant activity [2,2-diphenyl-1-picrylhydrazyl (DPPH) free-radical scavenging ability, 2,2'-azino-di(2-ethyl-benzthiazoline-sulfonic acid-6) ammonium salt (ABTS) free-radical scavenging ability, and ferric-reducing antioxidant capacity power (FRAP)] also increased by 40.91%, 22.60%, and 3.65%, respectively, during fermentation. A total of 55 volatile flavour compounds were detected using HS-SPME-GC-MS among the uninoculated samples and fermented samples before and after fermentation. The results showed that fermentation increased the types and total amount of volatile components in apple-tomato pulp, and eight new alcohols and seven new esters were formed. Alcohols, esters, and acids were the main volatile components in apple-tomato pulp, accounting for 57.39%, 10.27%, and 7.40% of the total volatile substances, respectively.

Construction of the first high-density genetic linkage map and QTL mapping of flavonoid and leaf-size related traits in Epimedium

BackgroundLeaves are the main medicinal organ in Epimedium herbs, and leaf flavonoid content is an important criterion of Epimedium herbs. However, the underlying genes that regulate leaf size and flavonoid content are unclear, which limits the use of breeding for Epimedium development. This study focuses on QTL mapping of flavonoid and leaf-size related traits in Epimedium.ResultsWe constructed the first high-density genetic map (HDGM) using 109 F1 hybrids of Epimedium leptorrhizum and Epimedium sagittatum over three years (2019–2021). Using 5,271 single nucleotide polymorphism (SNP) markers, an HDGM with an overall distance of 2,366.07 cM and a mean gap of 0.612 cM was generated by utilizing genotyping by sequencing (GBS) technology. Every year for three years, 46 stable quantitative trait loci (QTLs) for leaf size and flavonoid contents were discovered, including 31 stable loci for Epimedin C (EC), one stable locus for total flavone content (TFC), 12 stable loci for leaf length (LL), and two stable loci for leaf area (LA). For flavonoid content and leaf size, the phenotypic variance explained for these loci varied between 4.00 and 16.80% and 14.95 and 17.34%, respectively.ConclusionsForty-six stable QTLs for leaf size and flavonoid content traits were repeatedly detected over three years. The HDGM and stable QTLs are laying the basis for breeding and gene investigation in Epimedium and will contribute to accelerating the identification of desirable genotypes for Epimedium breeding.

The transcription factors SbMYB45 and SbMYB86.1 regulate flavone biosynthesis in Scutellaria baicalensis

Scutellaria baicalensis Georgi is an important Chinese medicinal plant that is rich in the flavones baicalin, wogonoside, and wogonin, providing it with anti-cancer, anti-inflammatory, and antibacterial properties. However, although the biosynthetic pathways of baicalin and its derivates have been elucidated, the regulation of flavone biosynthesis in S. baicalensis is poorly understood. Here, we found that the contents of baicalin and its derivates increased and that baicalin biosynthetic pathway genes were induced in response to light, and baicalin and baicalein are not exclusively produced in the roots of S. baicalensis. Based on the fact that MYB transcription factors are known to play important roles in flavone biosynthesis, we identified SbMYB45 and SbMYB86.1 in S. baicalensis and determined that they bind to the promoter of the flavone biosynthesis gene SbCHI to enhance its transcription. Moreover, overexpressing SbMYB45 and SbMYB86.1 enhanced the accumulation of baicalin in S. baicalensis leaves. We demonstrate that SbMYB45 and SbMYB86.1 bind to the cis-acting element MBSII in the promoter of CHI to redundantly induce its expression upon light exposure. These findings indicate that SbMYB45 and SbMYB86.1 transcriptionally activate SbCHI in response to light and enhance flavone contents in S. baicalensis.

Effect of low temperature microwave treatment on lipid stability and antioxidant capacity of whole wheat flour

The aim of this study was to inactivate the enzyme and improve the lipid stability of whole wheat flour (WWF) by microwave (MW) heating. With the temperature of MW treatment reaching 70 °C and the time extending to 20 min, the activities of lipase, lipoxygenase, peroxidase and polyphenol oxidase of WWF decreased by 64.29%, 37.45%, 32.1% and 27.13% respectively. During storage, free fatty acids decreased with the increase of MW treatment temperature (60, 65 and 70 °C) and time (5, 10, 15 and 20 min), however the peroxide value did not change significantly. The effects of MW treatment on the color and antioxidant capacity of WWF were also compared. The results showed that the color, total phenolic content and antioxidant capacity of the MW-stabilized WWF were similar to those of the control, but were able to significantly inhibit the deterioration of L* and a* values of WWF. In addition, MW treatment at 70 °C for 20 min could significantly reduce the free flavone content of WWF. Overall, MW treatment is a promising stabilization method, which can maintain WWF quality and antioxidant capacity, which is very important for industrial production.

Effects of Magnesium on Transcriptome and Physicochemical Index of Tea Leaves.

Magnesium (Mg) is one of the essential elements for the growth of tea tree and is extremely important for its development. In this study, we investigated the effect of Mg on the transcriptome and physicochemical indexes of tea leaves, and the results showed that Mg could significantly affect the gene expression of tea leaves. The results of Orthogonal Partial Least-Squares Discriminant Analysis (OPLS-DA) model analysis showed that a total of 300 key genes (Variable Importance for the Projection, VIP > 1) were screened under different concentrations of Mg treatment, among which 140 genes were up-regulated and 160 genes were down-regulated. The bubble map was used to screen the characteristic genes from the above key genes, and a total of 121 representative characteristic genes were obtained, mainly involving 9 metabolic pathways. Among them, gene expression of three metabolic pathways, including porphyrin metabolism, alpha-linolenic acid metabolism and photosynthesis, showed an increasing trend with the increase of Mg concentration, while gene expression of four metabolic pathways, including biosynthesis of secondary metabolites, anthocyanin biosynthesis, ABC transporters, pentose and glucuronate interconversions, showed a decreasing trend. The results of physiological index analysis showed that with the increase of Mg concentration, the photosynthetic physiological index, theanine and soluble sugar content of tea leaves showed an increasing trend, while the content of tea polyphenol, flavone and caffeine showed a decreasing trend. The results of TOPSIS analysis showed that the physiological indexes of tea trees most affected by Mg were chlorophyll, tea polyphenols and flavonoids, while the metabolic pathways most affected by Mg on gene expression were the metabolic pathways and biosynthesis of secondary metabolites. It can be seen that the effects of Mg on tea tree were mainly related to photosynthesis and synthesis of secondary metabolites, and Mg was beneficial for improving the photosynthetic capacity of tea tree, enhancing the accumulation of primary metabolites, and thus increasing tea yield. However, Mg was not conducive to the synthesis of secondary metabolites of tea tree and the accumulation of main quality indexes of tea leaves.

Effect of Fermentation Humidity on Quality of Congou Black Tea.

This study investigated the effect of different fermentation humidities (55%, 65%, 75%, 85% and 95%) on congou black tea quality and bioactivity. Fermentation humidity mainly affected the tea's appearance, aroma and taste quality. The tea fermented at low humidity (75% or below) showed a decrease in tightness, evenness and moistening degree, as well as a heavy grassy and greenish scent, plus a green, astringent and bitter taste. The tea fermented at a high humidity (85% or above) presented a sweet and pure aroma, as well as a mellow taste, plus an increase of sweetness and umami. With increasing fermentation humidity, the tea exhibited a drop in the content of flavones, tea polyphenols, catechins (EGCG, ECG) and theaflavins (TF, TF-3-G), contrasted by a rise in the content of soluble sugars, thearubigins and theabrownins, contributing to the development of a sweet and mellow taste. Additionally, the tea showed a gradual increase in the total amount of volatile compounds and in the content of alcohols, alkanes, alkenes, aldehydes, ketones and acids. Moreover, the tea fermented at a low humidity had stronger antioxidant activity against 2, 2-Diphenyl-1-picrylhydrazyl (DPPH) and a higher inhibiting capability on the activities of α-amylase and α-glucosidase. Overall results indicated the desirable fermentation humidity of congou black tea should be 85% or above.

Impact of Light and Dark Treatment on Phenylpropanoid Pathway Genes, Primary and Secondary Metabolites in Agastache rugosa Transgenic Hairy Root Cultures by Overexpressing Arabidopsis Transcription Factor AtMYB12.

Agastache rugosa, otherwise called Korean mint, has a wide range of medicinal benefits. In addition, it is a rich source of several medicinally valuable compounds such as acacetin, tilianin, and some phenolic compounds. The present study aimed to investigate how the Tartary buckwheat transcription factor AtMYB12 increased the primary and secondary metabolites in Korean mint hairy roots cultured under light and dark conditions. A total of 50 metabolites were detected by using high-performance liquid chromatography (HPLC) and gas chromatography-time-of-flight mass spectrometry (GC-TOFMS). The result showed that the AtMYB12 transcription factor upregulated the phenylpropanoid biosynthesis pathway genes, which leads to the highest accumulation of primary and secondary metabolites in the AtMYB12-overexpressing hairy root lines (transgenic) than that of the GUS-overexpressing hairy root line (control) when grown under the light and dark conditions. However, when the transgenic hairy root lines were grown under dark conditions, the phenolic and flavone content was not significantly different from that of the control hairy root lines. Similarly, the heat map and hierarchical clustering analysis (HCA) result showed that most of the metabolites were significantly abundant in the transgenic hairy root cultures grown under light conditions. Principal component analysis (PCA) and partial least-squares discriminant analysis (PLS-DA) showed that the identified metabolites were separated far based on the primary and secondary metabolite contents present in the control and transgenic hairy root lines grown under light and dark conditions. Metabolic pathway analysis of the detected metabolites showed 54 pathways were identified, among these 30 were found to be affected. From these results, the AtMYB12 transcription factor activity might be light-responsive in the transgenic hairy root cultures, triggering the activation of the primary and secondary metabolic pathways in Korean mint.

A study of a complex of bioactive compounds in the fruits of promising blue honeysuckle (&lt;i&gt;Lonicera caerulea&lt;/i&gt;l.) cultivars

Background. Blue honeysuckle (Lonicera caerulea L.) is a valuable source of bioactive compounds (BAC) of polyphenolic nature and rare for horticultural berries iridoids, which have antioxidant, anti-inflammatory, antimicrobial and other properties and are widely used in the food, medical and cosmetic industries.Materials and methods. The berries of 20 released honeysuckle cultivars of Russian, Canadian and U.S. origin, reproduced at the I.V. Michurin Federal Science Center in Tambov Province, were studied for the content of the main BAC groups using modern methods (spectrophotometry, HPLC-UV, HPLC-RID, and HPLC-DAD-MS).Results and discussion. The main BAC groups (the content and profile of anthocyanins, proanthocyanidins, flavonols and flavones, hydroxycinnamic acids (HCA), iridoids, and organic acids) as well as mono- and disaccharides were studied in detail. A comparative study of the biological value of domestic and foreign honeysuckle cultivars was carried out.Conclusions. The study resulted in identifying the most promising cultivars of honeysuckle according to the content of the main BAC groups.