Flavonoid Composition Research Articles

Widely targeted metabolomics reveals the effect of different raw materials and drying methods on the quality of instant tea.

Instant teas are particularly rich in tea polyphenols and caffeine and have great potential as food ingredients or additives to improve the quality of food and enhance their nutritional and commercial value. To determine the relationships between raw material, drying method, and sensory and other quality attributes, instant teas were prepared from three tea varieties, namely black, green and jasmine tea, using two drying methods, namely spray-drying (SD) and freeze-drying (FD). Both the raw tea material and drying method influenced the quality of the finished instant teas. Black tea was quality stable under two drying, while green tea taste deteriorated much after SD. Jasmine tea must be produced from FD due to huge aroma deterioration after SD. FD produced instant tea with higher sensory quality, which was attributed to the lower processing temperature. Chemical compositional analysis and widely targeted metabolomics revealed that SD caused greater degradation of tea biochemical components. The flavonoids content changed markedly after drying, and metabolomics, combined with OPLS-DA, was able to differentiate the three varieties of tea. Instant tea preparations via SD often lost a large proportion of the original tea aroma compounds, but FD minimized the loss of floral and fruity aroma compounds. Changes in the tea flavonoids composition, especially during drying, contributed to the flavor development of instant tea. These results will provide an practicle method for high-quality instant tea production through choosing proper raw tea material and lowering down drying temperature with non-thermal technologies like FD.

FLAVONOIDS OF AERIAL PARTS OF SPREADING MARIGOLD (TAGETES PATULA L.)

The arial parts of the spreading marigold (Tagetes patula L.) of the Asteraceae family is a promising source of biologically active compounds, including flavonoids. It is known, that the content of total flavonoids in the flowers of this plant reaches 9% (calculated on patulitrin), and in the aboveground part (leaves and stems) – about 3.0% (calculated on rutin), however, data on the component composition of flavonoids are contradictory.
 The aim of the study is to study the flavonoid component composition of the arial p part of the rejected marigolds.
 As a result of studies using column chromatography on silica gel L 40/100, 6-methoxykaempferol (2), 7-O-glucoside of methoxykaempferol (3), quercetin (6), patuletin (7) and patulitrin (7-O-β-D-glucopyranoside of patuletin) (12) were isolated for the first time from the flowers of Tagetes patula L. (Mandarin variety), and from the arial parts (leaves and stems) of this species - kaempferitrin (3-O-α-L-rhamnopyranoside-7-O-α-L-rhamnopyranoside of kaempferol) (4), 3-O-β-D-xylopyranoside-7-O-α-L-rhamnopyranoside of kaempferol (5), quercetin (6), patuletin (7), 3-O-β-D-xylopyranoside-7-O-α-L-rhamnopyranoside of quercetin (8), 7-O-α-L-rhamnopyranoside of quercetin (9), quercitrin (10), isoquercitrin (11). Interestingly, that the common components of the herbs (leaves and stems) and flowers are only two flavonoids – quercetin (6) and patuletin (7). As for patulitrin (7-O-β-D-glucopyranoside of 3,5,7,3’,4’-pentahydroxy-6-methoxyflavone, or patuletin) (12), which is the dominant flavonoid of the flowers of this plant, this component is not found in the herbs of this plant. It was determined, that glycosides of kaempferol (1) and quercetin (6) predominate in the herb of the Tagetes patula L. with the dominant flavonoid being 3,7-O-dirhamnoside of kaempferol (4).
 The identification of the isolated flavonoids was carried out using UV, 1H-NMR, 13C-NMR spectroscopy and mass spectrometry, as well as the results of acid and enzymatic hydrolysis.
 3-O-β-D-xylopyranoside-7-O-α-L-rhamnopyranoside of kaempferol (5) and 3-O-β-D-xylopyranoside-7-O-α-L-rhamnopyranoside of quercetin (8), isolated from the herb of the Tagetes patula L., are new natural compounds.

Interpopulation Variability of Polyphenol Concentration in the Leaves of <i>Spiraea aquilegifolia</i> (Rosaceae) from the Republic of Buryatia

Abstract—Composition and content of flavonoids and phenol carboxylic acids in the leaves of Spiraea aquilegifolia Pall. from natural populations of the Republic of Buryatia (Western Transbaikalia) are given in the article. Aqueous ethanol (40%) extracts from raw materials were used for chromatographic study of phenolic compounds. The analysis of phenolic compounds was carried out on an analytical High-Performance Liquid Chromatography (HPLC) system consisting of an Agilent 1200 liquid chromatograph (USA) with a diode array detector, an autosampler, and a system for collecting and processing chromatographic data ChemStation. At least 24 phenolic compounds were identified in aqueous ethanol extracts from Spiraea aquilegifolia Pall. leaves by HPLC. Three acids (chlorogenic, p-coumaric and p-hydroxybenzoic) and six flavonols (hyperoside, isoquercitrin, avicularin, astragalin, quercitrin and kaempferol) were identified among them. Flavonols hyperoside (2.9–8.2 mg/g), avicularin (3.0–5.8 mg/g) and isoquercitrin (0.8–2.5 mg/g) are the main substances in aqueous ethanol extracts from leaves. Plants from populations located at the northern distribution limit in the Western Transbaikalia have a higher content of phenol carboxylic acids (near the village Koma) and flavonols (near the village Klyuchi). Plants from populations located to the eastern limit (near villages Kusoty and Zagan) have the lowest concentration of identified phenolic compounds. A high and very high level of interpopulation variability of the studied biochemical parameters has been established. This can be explained by the functional significance of the identified compounds and their active participation in general metabolic processes in the plant. The content of identified free phenolic acids and flavonols in S. aquilegifolia was characterized by medium and high levels, compared to other studied Spiraea species. This confirms the prospects for further study of the composition of phenolic compounds of S. aquilegifolia.

Recommendation to Consume Plant Products for their Health Benefits may Take a Different Perspective with Global Warming

Abstract: Over the past few decades, the multifaceted anticancer action of various plant-derived flavonoids has been demonstrated both in in vitro and in vivo preclinical experiments as well as in clinical trials and large-scale epidemiological studies. These secondary metabolites, synthesized in plants in response to different environmental stresses, can exert diverse biological activities in the human body after ingestion of plant-based foods. Flavonoids are indeed well-known for their antioxidant, anti-inflammatory, antiproliferative, proapoptotic, anti-migratory, antiinvasive, anti-metastatic, and anti-angiogenic properties, thereby preventing and slowing the development of different types of human cancers. Accordingly, more and more people all over the world have increased their everyday intake of fruits, vegetables, whole grains, and spices to get the benefits of flavonoids. In this commentary article, a critical view is presented on the possible gradual decrease in the health-promoting effects of edible and medicinal plant products related to changes in their flavonoid content and composition as a consequence of global warming. It is indeed generally accepted that biosynthesis and accumulation of certain flavonoids can be higher in plants cultivated in colder conditions, while a high temperature may even block the production of these agents. It only remains to be determined in the future as to what extent the lowering of flavonoids content in plant-based diets during global warming can contribute to continuously increasing worldwide incidence of new cancer cases, revealing the actual costs of human-induced environmental changes.

The effects of Monascus purpureus fermentation on metabolic profile, α-glucosidase inhibitory action, and in vitro digestion of mulberry leaves flavonoids

Mulberry leaves (MLs) were considered to have great hypoglycemic potential because of their rich flavonoid compounds. To enhance the hypoglycaemic effect of MLs, we exploited the fermentation potential of Monascus purpureus to improve its flavonoid profile. Targeted metabolomics analysis showed that we optimized flavonoid composition by subjecting MLs to M. purpureus fermentation. Significant improvements in flavonoid content were observed, with both solid-state fermentation (SSF) and submerged fermentation (SMF) enhancing the flavonoid profiles. Specifically, kaempferol and quercetin were significantly upregulated, whereas astragalin, isoquercetin, and rutin were downregulated, suggesting enhanced antidiabetic properties. Our investigation revealed the metabolic pathways that emphasize the importance of flavonoid biosynthesis. Enhanced α-glucosidase (AG) inhibitory activities were identified in fermented MLs, which are essential for diabetes management. The IC50 values for the inhibitory activities of SSF-MLs and SMF-MLs against AG reached 112.80 ± 1.29 μg/mL and 123.90 ± 0.96 μg/mL, respectively. The types of AG inhibition by the seven major flavonoids were revealed by enzyme inhibition kinetics. Molecular docking revealed the interaction mechanisms underlying AG inhibition. Furthermore, our study demonstrated that SMF optimizes the bioavailability of flavonoids during in vitro digestion. This study presents M. purpureus-assisted MLs fermentation as an relevant strategy, enriching its therapeutic potential for diabetes.

A novel non-centrifugal sugar prepared from tiger nut (Cyperus esculentus L.) meal: Preparation methods and comparison with sugarcane

The lack of research on the rich sucrose in tiger nut meal has been a major obstruction to the comprehensive utilization of tiger nut (Cyperus esculentus L.). In this study, for the first time, tiger nut meal was used to producing non-centrifugal sugar (NCS). Three samples − NCS-W1 (NCS prepared by water extraction and concentrated at 115 °C), NCS-W2 (NCS prepared by water extraction and concentrated at 135 °C), and NCS-E (NCS prepared by 70 % ethanol–water extraction and concentrated at 115 °C) were obtained, with yields of 14.25–14.59 %. These samples and sugarcane NCS products (NCS-C1, NCS-C2, NCS-L) were compared and analyzed in terms of color, pH, turbidity, soluble solid content, and proximate composition. Their Fourier-transformed infrared spectra, crystal patterns, and thermal stabilities were also analyzed. The NCS-W1, -W2, and -E showed excellent performance, and they were better than sugarcane NCS products in terms of free radical scavenging ability and cytoprotective effects. Differences in phenolic acid composition, flavonoid composition, amino acid, mineral content, and vitamins C and E content were also analyzed. This work demonstrates that tiger nut meal might be a new source of NCS. As such it would contribute to the full utilization of tiger nut.

Bioactive properties and volatile compounds of the essential oil of the leaves of giant fennel (Çaksır) growing in Türkiye

In the present study, the chemical composition and total phenolic and flavonoid values of the essential oil (EO) of leaves of Ferula communis L. were evaluated and their in vitro antifungal activities against six foodborne saprophytic mold species were tested. Detection of the compounds of the EO was done using gas chromatography and mass-selective detection. Twenty-five different components were determined in F. communis EO, primarily including α-eudesmol (28.53%), β-eudesmol (20.88%), γ-eudesmol (10.15%), and caryophyllene oxide (9.11%). The antioxidative activity of the volatile oils was determined by DPPH (14.455 μg/mL), ABTS (23.015 μg/mL), and FRAP (7.945 μmol Fe/g) methods. The total phenolic (20.091 mg GAE/g) and total flavonoid (0.196 mg QE/g) compositions were also specified. The antifungal activities of the EO were investigated using disc diffusion and broth microdilution methods. The EO showed the highest antifungal activity against Penicillium digitatum (inhibition zone diameter 23.96 mm; (P<0.05). The minimum inhibitory concentrations (MICs) and minimum fungicidal concentrations (MFCs) of the EO of F. communis leaves ranged from 0.0180 to 0.235 mg/L and 0.012 to 0.096 mg/L, respectively, for the foodborne saprophytic molds (P<0.05). According to the MIC/MFC ratios, the EO of F. communis exerted lethal effects on four of the studied mold species and inhibitory effects on the remaining five.

Analysis of the Flavonoidome Reveals the Different Health-Promoting Flavonoid Characteristics in Fruit.

Flavonoids are one of the important metabolites of plants, and many flavonoids have functions of antioxidant or antimicrobial, which can help plants resist environmental stress. On the other hand, flavonoids also have a health-promoting effect for humans, such as antioxidant and anti-aging, and some flavonoids can assist in disease treatment. Fruit is one of the main sources of plant food and flavonoids intake for humans. Understanding the flavonoidome of various fruits is helpful to choose fruit combinations according to different demands. In this study, we explored the composition and relative content of flavonoids in 22 fruits and analyzed some health-promoting flavonoids in fruits. In addition, we selected several fruits and measured their antioxidant capacity through experiments. Our study initially established a database of fruit flavonoidome, and can provide reference for nutrition research, fruit breeding and industrial development.

Pharmaceutical Activity of Medicinal Plant Amaranthus viridis Linn. Due to Its Chemical Constituents: A Review

Background: Amaranthus viridis, a herbal plant belonging to the family Amaranthaceae, has gained significant attention in the field of traditional medicine due to its rich chemical composition. This plant is known to contain various bioactive components that contribute to its pharmaceutical value. With its extensive range of chemical compounds, Amaranthus viridis has found applications in therapeutic, pharmaceutics, and cosmetic industries. In this study, we aim to explore the medicinal potential of Amaranthus viridis and investigate its various pharmaceutical activities. Methods: The process of writing this review involved conducting comprehensive electronic research using reputable sources, including international and national article databases, along with books accessed through platforms like Google Scholar, PubMed, IEEE Xplore, ScienceDirect and others. The gathered data is subsequently analyzed, followed by employing synthetic approaches with narrative methods to derive meaningful conclusions and interpretations. Results: Amaranthus viridis displays potent antioxidant and anti-inflammatory properties, attributed to its rich composition of flavonoids, cardiac glycosides, and zinc. Its diverse pharmaceutical activities make it a promising contender for medicinal use, addressing labor pain, skin conditions like eczema and psoriasis, and respiratory issues, while also exhibiting antimicrobial effects against bacteria, fungi, and parasites. It can be accomplished by Extraction with solvent, Phytochemical screening and Isolation and purification. Conclusion: Amaranthus viridis, a herbal plant, shows significant potential in therapeutic, pharmaceutics, and makeup industries. Its bioactive compounds, including flavonoids, cardiac glycosides, and zinc, contribute to its diverse pharmaceutical activities, such as antioxidant, anti-inflammatory, antibacterial, antifungal, antidiabetic, and antihelmintic properties.

Ecological Studies of Tridax procumbens (Linn) and Ageratum conyzoides (Linn) and the comparative Studies of Their Phytochemical

Tridax procumbens and Ageratum conyzoides are two plant species commonly found in tropical regions and have been used in traditional medicine for various purposes. Field surveys were conducted in selected sites across Nnamdi Azikiwe University, Awka, Nigeria to assess the distribution and abundance of the two species. Data on soil moisture, light intensity, temperature, and altitude were also collected to determine the ecological factors that influence their growth and distribution. Phytochemically, the main constituents present in these plants using various techniques including chromatography and spectroscopy were isolated and identified. Results showed that the two plants have different ecological niches and exhibit varying levels of phytochemical diversity. Both plants were found to contain compounds such as flavonoids, alkaloids, and terpenoids, which may have potential medicinal properties. The leaves of Tridax procumbens and Ageratum conizoides were used for this study, and it was evaluated and compared for total saponin, total flavonoids and other secondary metabolites using standard procedures. The study of two different samples from the two plant species revealed the presence of saponin, tannin, alkaloid, flavonoid, steroid. The dried sample of Tridax gave a higher composition of saponin (1.85±0.03 mg/100g), flavonoids (1.34±0.03 mg/100g), tannin (2.51±0.02 mg/100g), alkaloids (1.49±0.02 mg/100g) and steroid (0.26±0.02 mg/100g), while the dry sample of Ageratum gave a composition of (1.68±0.03 mg/100g) of total saponins, (1.95±0.03 mg/100g) of total flavonoids, (0.06±0.02 mg/100g) of total phenol, (2.14±0.02 mg/100g) of alkaloids, (0.26±0.02 mg/100g) of total Terpenoid. There is significant difference between the phytochemicals seen in the two samples. Thus, this reveals that Tridax plant has more tannin which is used medicinally to lower total cholesterol and lower blood pressure, while Ageratum plant contains more saponins which is used medicinally to decrease blood lipids and lower cancer risks.

The Therapeutic Potential of Natural Dietary Flavonoids against SARS-CoV-2 Infection.

The exploration of non-toxic and cost-effective dietary components, such as epigallocatechin 3-gallate and myricetin, for health improvement and disease treatment has recently attracted substantial research attention. The recent COVID-19 pandemic has provided a unique opportunity for the investigation and identification of dietary components capable of treating viral infections, as well as gathering the evidence needed to address the major challenges presented by public health emergencies. Dietary components hold great potential as a starting point for further drug development for the treatment and prevention of SARS-CoV-2 infection owing to their good safety, broad-spectrum antiviral activities, and multi-organ protective capacity. Here, we review current knowledge of the characteristics-chemical composition, bioactive properties, and putative mechanisms of action-of natural bioactive dietary flavonoids with the potential for targeting SARS-CoV-2 and its variants. Notably, we present promising strategies (combination therapy, lead optimization, and drug delivery) to overcome the inherent deficiencies of natural dietary flavonoids, such as limited bioavailability and poor stability.

Flavonoids‑targeted metabolomic analysis following rice yellowing

Flavonoids are the main metabolites responsible for yellowing of rice. However, the accumulation pattern of flavonoids and the metabolic basis of flavonoid biosynthesis during rice yellowing remain unclear. Thus, flavonoid-targeted metabolomics was used to investigate the composition and concentration of flavonoids in rice during yellowing. The results indicated the differential flavonoids at Month 3 and Month 5 of storage were more in composition and concentration with higher antioxidant capacity. Accumulated flavonoids were mainly flavones, flavonols, isoflavones, and anthocyanidins, of which rutin, farrerol, naringenin, cyanidin 3-rutinoside, and diosmetin were the indicators of rice yellowing. Metabolic association among flavonoids demonstrated the formation of yellow pigments was jointly induced by flavones, flavonols, isoflavones, and anthocyanidins metabolism. Examination of flavonoid metabolism presented in this study enhanced current understanding of the relationship between flavonoid metabolites and development of rice yellowing. It also offers a theoretical basis for targeted prediction of rice yellowing in the future.

Integrated Analysis of Transcriptome and Metabolome Reveals New Insights into the Molecular Mechanism Underlying the Color Differences in Wolfberry (Lycium barbarum)

Wolfberry (Lycium barbarum L.) is a small Solanaceae shrub with medicinal and edible homology, and widely used as ethnobotanical medicine and nutraceutical food. The wolfberry fruits mainly have red, purple, and yellow phenotypes. Wolfberries are rich in flavonoids, which are natural water-soluble pigments that endow a variety of colors in plants There are very few investigations on mechanism of flavonoids biosynthesis and fruit coloring reported about wolfberry. The widely targeted metabolome and transcriptome analysis were performed to obtain metabolite and gene expression profiles of red, yellow, and purple wolfberries and to explain the underlying molecular mechanism of the color differences in wolfberry. As result, metabolomics analysis revealed that the bluish anthocyanins Malvidin and petunidin trended to accumulate in purple wolf-berry, while red and yellow wolfberries trended to accumulate more yellowish flavonoids. And transcriptome analysis showed that flavonoid synthesis-related genes, such as CHS, F3H, ANS and DFR, and several MYB and bHLH genes were differentially expressed among wolfberries in different colors: most of them were more highly expressed in purple wolfberries than in red and yellow ones. In conclusion, the different flavonoids’ accumulation patterns may result in the different fruit colors of wolfberry, and the MYB or bHLH transcription factors could regulate the expression of flavonoids biosynthesis related genes to change the composition of flavonoids or anthocyanins in wolfberry fruits and result in varied fruit colors. These findings provide new insights into the underlying molecular mechanism of the fruit color differences in wolfberry and provide new ideas for molecular breeding of wolfberry.

Unveiling the phytochemical and pharmacological potential of Mimusops maxima (Poiret) Vaughan-an endemic plant with potential therapeutic effects

Mimusops maxima (Poiret) Vaughan is an endemic plant of Mauritius Island that has never been studied for neither its phytochemical nor pharmacological properties. Hence this study targeted to extract the phytochemicals using three different solvents and characterizion them through HPLC-MS-MS, alongside investigating their effects against chronic diseases. The methanolic extract beared the highest total phenolic and total flavonoid composition, (31.10 ± 0.25 gallic acid equivalents/gram (GAE/g) and 38.68 ± 0.34 rutin equivalent (mgRE/g)), respectively), succeeded by the ethyl acetate and aqueous extracts. The antioxidant assay demonstrated that the methanolic extract had the highest potency in terms of antioxidant potential. The most potent acetylcholinesterase enzyme inhibitor was the ethyl acetate extract (4.78 ± 0.28 mg GALAE/g) followed by the methanolic extract (4.48 ± 0.05 mgGALAE/g). The most inhibition of the tyrosinase enzyme was generated by the methanolic extract (122.53 ± 2.72 mg KAE/g),the ethyl acetate extract and aqueous extracts (113.96 ± 1.53 and 6.19 ± 0.30 mg KAE/g, respectively) followed and were behind the methanolic extract. The methanolic and ethyl acetate extracts can be formulated as tissanes and extracts as health supplements as a prophylaxis measure for non-communicable diseases pending further toxicological investigations.

THE PROBLEMS TO IMPROVE THE STANDARDISATION OF YARROW HERB

Relevance. It is known the method of quantitative determination of the total flavonoids in the herb of common yarrow (Achillea millefolium L.) includ-ed in the State Pharmacopoeia of the Russian Federation XIV edition, according to which at the stage of extraction of these raw materials should be ac-id hydrolysis with ethyl alcohol 96% containing 1% hydrochloric acid concentrated, followed by determination of the amount of flavonoids in recalcula-tion on luteolin. The flavonoid glycosides, including 7-O-glucosides luteolin (cynaroside) and apigenin (cosmosiin), difficult to acid hydrolysis, which does not allow for complete hydrolysis and exhaustive extraction of the target substances. Determination of the main groups of biologically active substances by thin-layer chromatography (TLC) involves the use of a standard sample of sudan III, not contained in the raw material. The purpose of this study is the improvement of methods of qualitative and quantitative analysis of herb of Achillea millefolium L. Material and methods. Yarrow herb harvested in 2021 was used as study materials. Extraction of individual substances from yarrow herbs was car-ried out using column chromatography on silica gel KSC 50/100 under conditions of gradient elution with chloroform-ethanol solvent mixture in different ratios. Along with the isolated individual flavonoids, we used working standard samples of flavonoids obtained by the authors in previous studies of herbal plants containing flavonoids, characterized using UV and NMR spectroscopy: rutin, quercetin, kaempferol, cynaroside, luteolin. Flavonoid content was determined by thin-layer chromatography and by differential spectrophotometry. Results. TLC analysis revealed the presence of three dominant and diagnostically significant flavonoids: cosmosiin, cynaroside and apigenin. Analysis of UV spectra also confirmed that the spectral characteristics of the water-alcoholic extracts from common yarrow herbs, especially under the condi-tions of differential spectrophotometry, are mainly determined by the dominant flavones (cosmosiin, cynaroside and apigenin). Conclusions. The obtained results of studies on the flavonoid composition and spectral characteristics of the isolated dominant flavonoids suggest the feasibility of conducting of the qualitative and quantitative analysis of common yarrow herbs using cynaroside as a standard sample.

Effect of desert locust control on non-target edible termites in eastern Uganda

Effects of widescale locust control with insecticides on non-target edible insects have been scarcely assessed. This study was carried out to investigate the effect of spraying desert locust with cypermethrin and chlorpyrifos on: (1) termite mound activity; (2) safety of edible termites from contamination with pesticide residues; and (3) nutritional composition of non-target edible termites. Incidences of inactive termitaria in the sprayed and unsprayed sites were enumerated. Edible soldiers ofMacrotermes spp. from sprayed and unsprayed colonies whose alates swarm around dusk, midnight and dawn were analysed for cypermethrin and chlorpyrifos residues, and proximate, mineral and flavonoid compositions. The pesticide sprays did not influence the incidence of inactive termitaria. No cypermethrin and chlorpyrifos residues were detected in the termites. Chlorpyrifos spraying lowered crude fibre and protein contents in soldiers of dawn and midnight swarming colonies, respectively; whereas cypermethrin spraying lowered ash and crude fat contents in soldiers from dawn and dusk swarming colonies, respectively. Cypermethrin spraying increased moisture content in soldiers from midnight swarming colonies. The level of manganese in soldiers from dawn swarming colonies was lowered by cypermethrin spraying, while contents of aluminium and cobalt from the same type of colony were lowered by chlorpyrifos spraying. However, levels of calcium, potassium, magnesium, phosphorus, zinc, aluminium, manganese and iron were enhanced in soldiers from different termite colonies sprayed with cypermethrin and/or chlorpyrifos. Similarly, soldier termite samples from both insecticide sprayed sites contained higher flavonoid levels than the samples from unsprayed sites. Freedom of the edible soldier termites from the pesticides residues renders them safe for consumption. The results provide insights into the likely effects of wide-scale pesticide sprays against locust on the nutritional profiles of edible termites.

Ultrasonic-assisted extraction of flavonoids from Nitraria sibirica leaf using response surface methodology and their anti-proliferative activity on 3T3-L1 preadipocytes and antioxidant activities.

As both an edible and medicinal plant, Nitraria sibirica has been used as a natural remedy for indigestion and hypertension since ancient times in Central Asia. The ethanolic extract of N. sibirica leaves lowers blood pressure and blood lipids. We assume that these bioactivities are most likely related to the composition of flavonoids due to their dominant content. Therefore, we investigated bioactivity-oriented extraction parameters of flavonoids from N. sibirica. In this study, the ultrasonic-assisted extraction variables were optimized using a response surface methodology for optimal recoveries of total flavonoid content (TFC), anti-proliferative activity on 3T3-L1 preadipocytes and antioxidant capacities (DPPH) of N. sibirica leaf extract (NLE). The optimal extraction conditions of NLEs were as follows: ethanol concentration of 71.33%, feed-to-solvent ratio of 30.36mL/g, extraction temperature of 69.48°C, extraction time of 25.27min, extraction number of two times, the TFCs were 1.73±0.01mg RE/g d.w. (n=4), IC50 value of preadipocytes was 259.42±3.62µg/mL (n=4), and antioxidant capacity of 86.55±3.71% (n=4). After the purification of NLEs, the TFCs were 7.52mg RE/g d.w., the inhibition capacity of IC50 was 143.50µg/mL, and DPPH scavenging rate was 86.99%, which were approximately 4.34, 1.81, and 1.01 folds higher than before the purification of NLEs, respectively. Bioactive-oriented extraction of NLEs possessed the potential lipid lowering and antioxidant activities, which hold high research value for the development of natural medicines or new functional foods to treat or prevent metabolic diseases such as obesity.

Flavonoid components and anti-photoaging activity of flower extracts from six Paeonia cultivars

Genus Paeonia is an important ornamental and medicinal crop. The flowers of Paeonia are rich in flavonoids, and flavonoids have excellent antioxidant and anti-inflammatory activities, which have the potential to slow down skin aging. In this study, flavonoids from whole flowers of six popular Paeonia cultivars were extracted using three different solvents. The composition and content of peony flowers flavonoids extracted with three solvents were determined by high performance liquid chromatography quadrupole time-of-flight mass spectrometry / mass spectrometry (HPLC-Q-TOF-MS/MS) and HPLC-diode array detection (DAD). A total of 26 flavonoids were isolated and identified, and 60 % ethanol showed the highest extraction efficiency. Not only flavonoids composition but also the content was significantly different in different peony flowers, among which ‘Hei Tian E’ had the most abundant composition (17 flavonoids) and the highest total content of flavonoids (57.75 mg/g DW by using 60 % ethanol). After that, the anti-skin photoaging effects of the 60 % ethanol extracts of the six Paeonia cultivars flowers were evaluated by UVR-Fulkutis and UVA-Fibroblasts photoaging models. Under exposure to UV radiation, some Paeonia flowers’ extracts can prevent the decrease of skin surface thickness and reduce the loss of Collagen IV and VII. In addition, the production and accumulation of ROS, MMP-1 and MMP-3 in fibroblasts were inhibited, indicating the attenuation of skin photoaging by the extracts. Among the six samples tested, ‘Hei Tian E’ whole flower extract (BH-HT) had the best comprehensive effect. Finally, the correlations between components and anti-photoaging efficacy were analyzed. We speculate that the anti-photoaging effect was significantly related to its richness in quercetin 3-O-di-glucoside, quercetin 3-O-glucoside, isorhamnetin 3-O-galloyl arabinoside, cyanidin 3,5-di-O-glucoside, cyanidin 3-O-glucoside, and peonidin 3-O-glucoside. In general, the results show that Paeonia flowers have potential for development of anti-photoaging herbal essence products.

Widely targeted metabolomic profiling combined with transcriptome analysis sheds light on flavonoid biosynthesis in sweet orange 'Newhall' (C. sinensis) under magnesium stress.

Sweet orange 'Newhall' peels (SOPs) are abundant in flavonoids, making them increasingly popular in the realms of nutrition, food, and medicine. However, there is still much unknown about flavonoid components in SOPs and the molecular mechanism of flavonoid biosynthesis when subjected to magnesium stress. The previous experiment conducted by the research group found that the total flavonoid content of Magnesium deficiency (MD) was higher than Magnesium sufficiency (MS) in SOPs. In order to study the metabolic pathway of flavonoids under magnesium stress, an integrative analysis of the metabolome and transcriptome was performed in SOPs at different developmental stages, comparing MS and MD. A comprehensive analysis revealed the identification of 1,533 secondary metabolites in SOPs. Among them, 740 flavonoids were classified into eight categories, with flavones identified as the dominant flavonoid component. The influence of magnesium stress on flavonoid composition was evaluated using a combination of heat map and volcanic map, which indicated significant variations between MS and MD varieties at different growth stages. The transcriptome detected 17,897 differential genes that were significantly enriched in flavonoid pathways. Further analysis was performed using Weighted gene correlation network analysis (WGCNA) in conjunction with flavonoid metabolism profiling and transcriptome analysis to identify six hub structural genes and ten hub transcription factor genes that play a crucial role in regulating flavonoid biosynthesis from yellow and blue modules. The correlation heatmap and Canonical Correspondence Analysis (CCA) results showed that CitCHS had a significant impact on the synthesis of flavones and other flavonoids in SOPs, as it was the backbone gene in the flavonoid biosynthesis pathway. The qPCR results further validated the accuracy of transcriptome data and the reliability of candidate genes. Overall, these results shed light on the composition of flavonoid compounds in SOPs and highlight the changes in flavonoid metabolism that occur under magnesium stress. This research provides valuable insights for improving the cultivation of high-flavonoid plants and enhancing our understanding of the molecular mechanisms underlying flavonoid biosynthesis.

Molecular characterization of a flavanone 3-hydroxylase gene from citrus fruit reveals its crucial roles in anthocyanin accumulation

BackgroundFlavanone 3-hydroxylase (F3H), a key enzyme in the flavonoid biosynthetic pathway, plays an important role in the regulation of flavonols and anthocyanidins accumulation. Citrus fruit is a rich source of flavonoids with varied flavonoid compositions among different varieties. To date, the study on F3H is limited in citrus, and its roles in regulating flavonoid accumulation in citrus fruit are still unclear.ResultsIn this study, we isolated a CitF3H from three different citrus varieties, Satsuma mandarin (Citrus unshiu Marc.), Ponkan mandarin (C. reticulata Blanco) and blood orange ‘Moro’ (C. sinensis Osbeck). Functional analysis showed that CitF3H encoded a functional flavanone 3-hydroxylase. It catalyzed the hydroxylation of naringenin to yield dihydrokaempferol, which was a precursor of anthocyanins in flavonoid biosynthetic pathway. In the juice sacs, CitF3H was differentially expressed among the three citrus varieties, and its expression level was positively correlated with the accumulation of anthocyanins during the ripening process. In the juice sacs of Satsuma mandarin and Ponkan mandarin the expression of CitF3H kept constant at an extremely low level, and no anthocyanin was accumulated during the ripening process. In contrast, the expression of CitF3H increased rapidly along with the accumulation of anthocyanin in the juice sacs of blood orange ‘Moro’ during the ripening process. In addition, we found that blue light irradiation was effective to up-regulate the expression of CitF3H and improve anthocyanin accumulation in the juice sacs of blood orange ‘Moro’ in vitro.ConclusionCitF3H was a key gene regulating anthocyanin accumulation in the juice sacs of citrus fruit. The results presented in this study will contribute to elucidating anthocyanin biosynthesis in citrus fruit, and provide new strategies to improve the nutritional and commercial values of citrus fruit.