Quercetin Glycosides Research Articles

Dual Functionality of Papaya Leaf Extracts: Anti-Coronavirus Activity and Anti-Inflammation Mechanism.

Papaya leaves have been used as food and traditional herbs for the treatment of cancer, diabetes, asthma, and virus infections, but the active principle has not been understood. We hypothesized that the anti-inflammatory activity could be the predominant underlying principle. To test this, we extracted papaya leaf juice with different organic solvents and found that the ethyl acetate (EA) fraction showed the most outstanding anti-inflammatory activity by suppressing the production of nitric oxide (NO, IC50 = 24.94 ± 2.4 μg/mL) and the expression of pro-inflammatory enzymes, such as inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX-2), and cytokines including interleukins (IL-1β and IL-6), and a tumor necrosis factor (TNF-α) in lipopolysaccharide (LPS)-induced RAW 264.7 cells. Transcriptomic analysis and Western blot results revealed its anti-inflammatory mechanisms were through the MAPK signaling pathway by inhibiting the phosphorylation of ERK1/2, JNKs, and p38 and the prevention of the cell surface expression of TLR4. Furthermore, we discovered that the EA fraction could inhibit the replication of alpha-coronavirus (HCoV-229E) and beta-coronavirus (HCoV-OC43 and SARS-CoV-2) and might be able to prevent cytokine storms caused by the coronavirus infection. From HPLC-QTOF-MS data, we found that the predominant phytochemicals that existed in the EA fraction were quercetin and kaempferol glycosides and carpaine. Counter-intuitively, further fractionation resulted in a loss of activity, suggesting that the synergistic effect of different components in the EA fraction contribute to the overall potent activity. Taken together, our results provide preliminary evidence for papaya leaf as a potential anti-inflammatory and anti-coronavirus agent, warranting further study for its use for human health promotion.

Green Extraction of Bioactive Compounds from Apple Pomace from the Cider Industry.

The cider-making industry in Asturias generates between 9000 and 12,000 tons of apple pomace per year. This by-product, the remains of the apple pressing, and made up of peel, flesh, seeds and stems, is a valuable material, containing substantial amounts of antioxidant compounds associated with healthy properties. Polyphenols such as dihydrochalcones and quercetin glycosides, and triterpenic acids, among which ursolic acid is a major compound, are the main antioxidant families described in apple pomace. The simultaneous recovery of those families has been accomplished by low frequency ultrasound-assisted extraction. Working extraction conditions were optimised by response surface methodology (RSM): time, 5.1 min; extractant composition, 68% ethanol in water; solid/liquid ratio, 1/75 and ultrasonic wave amplitude, 90%. This procedure was further applied to analyse those components in the whole apple pomace (WAP), apple peel (AP) and apple flesh (AF). On average, dry WAP contained almost 1300 µg/g of flavonols, 1200 µg/g of dihydrochalcones and 4200 µg/g of ursolic acid. These figures increased in the apple peel to, respectively 2500, 1400 and 8500 µg/g dry matter. Two linear multivariate regression models allowed the antioxidant activity of apple by-products to be predicted on the basis of their bioactive composition. The results derived from this study confirm the potential of industrial cider apple pomace as a source of high-value bioactive compounds, and the feasibility of the ultrasound-assisted extraction technique to recover those components in a simple and efficient way.

Qualitative and Quantitative Analysis of Stigmasterol from Iraqi Calendula officinalis

Calendula officinalis L. (Asteraceae) plant origin from Mediterranean countries, and in addition to the beauty of its flowers they also have important medicinal properties in the healing of many illnesses particularly skin issues. C. officinalis in the world was reported and assessed as a medicinal plant, like British pharmacopoeia (BP), European pharmacopoeia (EU), WHO and PDR. Calendula officinalis Linn. Contains 0.4% of flavonoids as minimum, calculated as Hyperoside of dried herbal substance according to British pharmacopeia (2). The Chemical Constituents are: Triterpene saponins, Triterpene (Stigmasterol), Flavonoids: isorhamnetin glycosides and quercetin glycosides, Coumarins: umbelliferon, scopoletin and aesculetin, Carotenoids: mainly zeaxanthin and Lutein (5). Stigmasterol is an essential ingredient that has been isolated from plants. Stigmasterol considered a progesterone precursor and serves as an intermediate in corticoids, androgens estrogens biosynthesis (10) and vitamin D3 synthesis (3). Stigmasterol is a triterpenes C30-derive phytosterol, naturally happening C28 and C29 carbon steroid alcohols that is similar to cholesterol in structure as well as biological activity (4).in this study Stigmasterol was identified by TLC, Mass analysis. Structure elucidation was performed using, FTIR and Mass analysis. The quantity of Stigmasterol was measured in the Iraqi plant.

Anti-arthritic potential and antioxidant properties of infusion, fractions and flavonoid glycosides from Dipteryx alata (baru) leaves

Dipteryx alata Vogel., popularly known as "baru", is a native species of Brazilian cerrado used by "Ribeirinhos" in the North Araguaia microregion. In the traditional medicine, maceration of barks or leaves infusion are used to treat back and muscle pain, osteoporosis and rheumatism. However, few studies have demonstrated the pharmacological effects of this species. The goal of this study was to perform phytochemicals studies of lyophilized infusion of D. alata leaves (LI-DA), as well as obtaining ethyl acetate fraction (EAF-DA) and hydromethanolic fraction (HMF-DA), and isolated flavonoids. The antioxidant of LI-DA, EAF-DA and HMF-DA, anti-inflammatory effects of LI-DA and quercetin-3-O-β-glucoside-7-O-α-rhamnoside (DA-1) and quercetin-7-O-α-rhamnoside (DA-2) were performed while in silico tests were used for absorption, distribution, metabolism, excretion and toxicity predictions of DA-1 and DA-2. LI-DA, EAF-DA and HMF-DA were evaluated in antioxidant assays (2, 2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid - ABTS; 2,2-diphenyl-1-picrylhydrazyl - DPPH; hydrogen peroxide - H2O2; reducing power and oxidation of β-carotene). The DA-1 and DA-2 were isolated from EAF-DA using chromatographic methods and characterized by Nuclear Magnetic Resonance (NMR) spectrometer. The Programs ProTox 3.0 and ADMETlab 2.0 were used for the prediction studies of DA-1 and DA-2. Mice received a single dose of LI-DA (3, 30, and 100 mg/kg), DA-1 (3 mg/kg) and DA-2 (3 mg/kg) and were subjected to inflammation induced by Complete Freund's Adjuvant (CFA) and in the zymosan-induced articular inflammation model. DA-1 and DA-2 have been identified for the first time in the leaves of D. alata. LI-DA, EAF-DA and HMF-DA demonstrated a high level of antioxidant activity as measured by ABTS (IC50 ≤ 5.62 μg/mL) and DPPH (IC50 ≤ 11.45 μg/mL). Oral administration of LI-DA (3, 30 and 100 mg/kg), DA-1 (3 mg/kg) and DA-2 (3 mg/kg) showed significantly reduced edema, cold and mechanical allodynia in the CFA-induced inflammation model (24 hours). LI-DA (3, 30, and 100 mg/kg) and DA-1 (3 mg/kg) reduced leukocytes migration into the joint cavity, mechanical allodynia, edema and NO production in mice (24 hours) in the zymosan-induced articular inflammation model. Additionally, DA-2 (3 mg/kg) reduced leukocyte migration and LI-DA (30 mg/kg) reduced protein exudation (24 hours) in zymosan model. DA-1 and DA-2 showed good oral bioavailability and low toxicity predicted by the ProTox model. This is the first chemical and biological study performed of D. alata infusion and two quercetin glycoside derivatives. The results indicated promising potential for the treatment of inflammation, pain, and rheumatism, supporting the traditional use of the infusion obtained from the leaves of D. alata.

Comparative phytochemical, antioxidant, and hemostatic studies of fractions from raw and roasted sea buckthorn seeds in vitro

Various seeds, including sea buckthorn (Hippophae rhamnoides L.) seeds, are sources of different bioactive compounds. They can show anti-inflammatory, hypoglycemic, anti-hyperlipidemic, antibacterial, antioxidant, or other biological properties in in vitro and in vivo models. Our preliminary in vitro results have demonstrated that the extracts from raw (no thermal processing) and roasted (thermally processed) sea buckthorn seeds have antioxidant potential and anticoagulant activity. However, it was unclear which compounds were responsible for these properties. Therefore, in continuation of our previous study, the extracts were fractionated by C18 chromatography. Phytochemical analysis of three fractions (a, b, and c) from raw sea buckthorn seeds and four fractions (d, e, f, and g) from roasted sea buckthorn seeds were performed. Several in vitro assays were also conducted to determine the antioxidant and procoagulant/anticoagulant potential of the fractions and two of their major constituents—isorhamnetin 3-O-β-glucoside7-O-α-rhamnoside and serotonin. LC–MS analyses showed that serotonin is the dominant constituent of fractions c and f, which was tentatively identified on the basis of its HRMS and UV spectra. Moreover, fractions c and f, as well as b and e, contained different B-type proanthocyanidins. Fractions b and e consisted mainly of numerous glycosides of kaempferol, quercetin, and isorhamnetin. The results of oxidative stress assays (measurements of protein carbonylation, lipid peroxidation, and thiol groups oxidation) showed that out of all the tested fractions, fraction g (isolated from roasted seeds and containing mainly dihexoses, and serotonin) demonstrated the strongest antioxidant properties.

Multi-omics analysis revealed the mechanism underlying flavonol biosynthesis during petal color formation in Camellia Nitidissima

BackgroundCamellia nitidissima is a rare, prized camellia species with golden-yellow flowers. It has a high ornamental, medicinal, and economic value. Previous studies have shown substantial flavonol accumulation in C. nitidissima petals during flower formation. However, the mechanisms underlying the golden flower formation in C. nitidissima remain largely unknown.ResultsWe performed an integrative analysis of the transcriptome, proteome, and metabolome of the petals at five flower developmental stages to construct the regulatory network underlying golden flower formation in C. nitidissima. Metabolome analysis revealed the presence of 323 flavonoids, and two flavonols, quercetin glycosides and kaempferol glycosides, were highly accumulated in the golden petals. Transcriptome and proteome sequencing suggested that the flavonol biosynthesis-related genes and proteins upregulated and the anthocyanin and proanthocyanidin biosynthesis-related genes and proteins downregulated in the golden petal stage. Further investigation revealed the involvement of MYBs and bHLHs in flavonoid biosynthesis. Expression analysis showed that flavonol synthase 2 (CnFLS2) was highly expressed in the petals, and its expression positively correlated with flavonol content at all flower developmental stages. Transient overexpression of CnFLS2 in the petals increased flavonol content. Furthermore, correlation analysis showed that the jasmonate (JA) pathways positively correlated with flavonol biosynthesis, and exogenous methyl jasmonate (MeJA) treatment promoted CnFLS2 expression and flavonol accumulation.ConclusionsOur findings showed that the JA-CnFLS2 module regulates flavonol biosynthesis during golden petal formation in C. nitidissima.

UPLC-MS/MS and HS-SPME-GC–MS reveal the flavor profiles of two geographical indications woody vegetables: Staphylea bumalda and Staphylea holocarpa

Staphylea bumalda (SHC) and Staphylea holocarpa (PGG) were recognized as geographical indication agricultural products due to unique flavor. 1218 differential non-volatile compounds and 536 differential volatile compounds were detected and identified through UPLC-MS/MS and HS-SPME-GC–MS methods. In SHC samples, catechins, epicatechins, proanthocyanidins, quinic acid derivatives, and kaempferol glycoside derivatives were the main flavor compounds, with bitter and harsh taste. L-tartaric acid, citraconic acid and citric acid were contributed to increase acidity. 4-Hexen-1-ol acetate, butanoic acid butyl ester, 3-Hexen-1-ol acetate, (E)-, and 3-Hexen-1-ol acetate, (Z)- were identified as characteristic odor compounds with strong floral, fruity and sweet odor. In PGG samples, epicatechin gallate, quercetin glycoside derivatives, L-histidine, and L-tyrosine were the leading contributors to bitter and harsh taste. The spicy, herbal, and bad smell odor were mainly brought by 2-octanol, and 3-Octen-1-ol, (Z)-. Our results offered comprehensive insights into the flavor and quality characteristics differences between PGG and SHC.

Development of a QTL marker for quercetin glycoside content in onion

Development of a QTL marker for quercetin glycoside content in onion

Phytochemical Analysis, Biological Activities, and Docking of Phenolics from Shoot Cultures of Hypericum perforatum L. Transformed by Agrobacterium rhizogenes.

Hypericum perforatum transformed shoot lines (TSL) regenerated from corresponding hairy roots and non-transformed shoots (NTS) were comparatively evaluated for their phenolic compound contents and in vitro inhibitory capacity against target enzymes (monoamine oxidase-A, cholinesterases, tyrosinase, α-amylase, α-glucosidase, lipase, and cholesterol esterase). Molecular docking was conducted to assess the contribution of dominant phenolic compounds to the enzyme-inhibitory properties of TSL samples. The TSL extracts represent a rich source of chlorogenic acid, epicatechin and procyanidins, quercetin aglycone and glycosides, anthocyanins, naphthodianthrones, acyl-phloroglucinols, and xanthones. Concerning in vitro bioactivity assays, TSL displayed significantly higher acetylcholinesterase, tyrosinase, α-amylase, pancreatic lipase, and cholesterol esterase inhibitory properties compared to NTS, implying their neuroprotective, antidiabetic, and antiobesity potential. The docking data revealed that pseudohypericin, hyperforin, cadensin G, epicatechin, and chlorogenic acid are superior inhibitors of selected enzymes, exhibiting the lowest binding energy of ligand-receptor complexes. Present data indicate that H. perforatum transformed shoots might be recognized as an excellent biotechnological system for producing phenolic compounds with multiple health benefits.

The component composition of the total flavonoid fractions from some <i>Ericaceae</i> family and their effect on the NO-stimulating activity of peritoneal macrophages

Introduction. Representatives of the Ericaceae family are quite common in Russia and are promising for the creation of new medicines of plant origin. At the same time, only 4 of them are official. The study of biologically active substances and pharmacological activity of Andromeda polifolia L., Chamaеdaphne calyculata (L.) Moench, Ledum palustre L., Empetrum nigrum L. with rich resource reserves is promising.Aim. Comparative study of the composition of total flavonoid fractions from A. polifolia, C. calyculata, L. palustre, E. nigrum and study of their effect on the NO-stimulating activity of peritoneal macrophagesMaterials and methods. The crushed aboveground part (leafy shoots) was previously depigmented with chloroform, treated with 70 % aqueous acetone, then acetone was removed. Flavonoids were extracted with ethyl acetate from the aqueous phase. The identification of flavonoids was carried out by HPLC (UltiMate 3000 chromatograph) according to the coincidence of retention times and spectral characteristics, the calculation of the content was carried out by simple normalization. The effect of the samples on nitric oxide production was studied on macrophages of C57BL/6 mice. Endotoxin control in the samples was carried out using a LAL test and cell incubation in the presence of polymyxin B.Results and discussion. The composition of flavonoid fractions from A. polifolia, C. calyculata, L. palustre and E. nigrum has been studied. 8 phenolic compounds were found in C. calyculata shoots, including isoquercitrin, herbacetin, naringenin and naringin – for the first time for this species. 5 compounds were detected in A. polifolia shoots, including isoquercitrin and herbacetin, for the first time for this species. 5 and 4 compounds were identified in L. palustre and E. nigrum shoots, respectively, while quercetin glycosides are predominant in all samples: isoquercitrin, hyperoside and rutin. The fraction of C. calyculata flavonoids at doses of 1, 5, 10 mcg/ml inhibits the production of nitric oxide by macrophages by 30 %, and E. nigrum flavonoids at doses of 100 and 200 mcg/ml, on the contrary, enhance the production of nitrites by macrophages by 33 and 37 %, respectively.Conclusion. A comparative study of the composition of total flavonoid fractions from A. polifolia, C. calyculata, L. palustre, and E. nigrum, which are capable of activating both M1 and M2 polarization of peritoneal macrophages in mice, has been conducted, which requires further in-depth study. The flavonoids C. calyculata and E. nigrum are promising for further study.

Optimization of Extraction and Purification of Flavonoids from Stigmaless Floral Residues of Crocus sativus L. and Their Stimulatory Effect on Glucose Uptake In Vitro.

Saffron, the dried stigma of Crocus sativus L., is a renowned spice and medicinal herb. During its production, a significant amount of floral residues, rich in bioactive compounds, are discarded as agricultural by-products. This study presents a novel approach to the sustainable utilization of these stigmaless floral residues (FRC) by optimizing the extraction and purification of their flavonoids, analyzing their chemical composition, and evaluating their effect on glucose uptake. The extraction of flavonoids from FRC was optimized using single-factor experiments and response surface methodology. The optimal conditions for extraction were an ethanol concentration of 67.7%, a temperature of 67.6 °C, a solid-to-liquid ratio of 1:30, an extraction time of 3 h, and two extractions. The crude extract obtained was then purified using macroporous resin HPD100, selected after comparing the adsorption and desorption characteristics of six different resins. The optimal purification parameters were an adsorption concentration of 40 mg/mL, a loading volume of 7 bed volumes (BV) at a flow rate of 3 BV/h, and 80% ethanol as the eluent with a volume of 4 BV. The resulting flavonoid-enriched extract (FFRC) had an experimental yield of 8.67% ± 0.01 and a flavonoid content of 128.30 ± 4.64 mg/g. The main flavonoids in FFRC were identified as kaempferol glycosides, isorhamnetin glycosides, and quercetin glycosides. Moreover, FFRC significantly stimulated glucose consumption and uptake in C2C12 myotubes, suggesting its potential utility as a natural hypoglycemic agent. This study contributes to the sustainable and value-added utilization of agricultural resources by providing data for the exploitation and application of flavonoids from saffron by-products.

Unveiling the Antimicrobial, Anti-Biofilm, and Anti-Quorum-Sensing Potential of Paederia foetida Linn. Leaf Extract against Staphylococcus aureus: An Integrated In Vitro-In Silico Investigation.

Antimicrobial resistance poses a global health threat, with Staphylococcus aureus emerging as a notorious pathogen capable of forming stubborn biofilms and regulating virulence through quorum sensing (QS). In the quest for novel therapeutic strategies, this groundbreaking study unveils the therapeutic potential of Paederia foetida Linn., an Asian medicinal plant containing various bioactive compounds, contributing to its antimicrobial activities, in the battle against S. aureus. Through a comprehensive approach, we investigated the effect of ethanolic P. foetida leaf extract on S. aureus biofilms, QS, and antimicrobial activity. The extract exhibited promising inhibitory effects against S. aureus including the biofilm-forming strain and MRSA. Real-time PCR analysis revealed significant downregulation of key virulence and biofilm genes, suggesting interference with QS. Biofilm assays quantified the extract's ability to disrupt and prevent biofilm formation. LC-MS/MS analysis identified quercetin and kaempferol glycosides as potential bioactive constituents, while molecular docking studies explored their binding to the QS transcriptional regulator SarA. Computational ADMET predictions highlighted favorable intestinal absorption but potential P-glycoprotein interactions limiting oral bioavailability. While promising anti-virulence effects were demonstrated, the high molecular weights and excessive hydrogen bond donors/acceptors of the flavonoid glycosides raise concerns regarding drug-likeness and permeability. This integrated study offers valuable insights for developing novel anti-virulence strategies to combat antimicrobial resistance.

A qualitative and quantitative analysis of polyphenolic compounds in five Epilobium spp. with a possible potential to alleviate benign prostatic hyperplasia

Benign prostatic hyperplasia (BPH) is a widespread male disease, affecting more than 50 % of men over the age of 60 years. Inhibition of the enzyme 5α-reductase is a common treatment strategy for this condition. Such potential can be found in willow flowers (Epilobium spp.), which are known in folk medicine for treating of prostate ailments, mainly benign prostatitis, hypertrophy and prostatitis. Smallflower hairy willowherb (E. parviflorum), which is rare, is the most recommended for treating BPH. The aim. The aim of the study was to investigate the qualitative and quantitative content of polyphenols in five Epilobium species (E. adenocaulon Hausskn., E. hirsutum L., E. montanum L., E. parviflorum Schreb. and E. palustre L.) growing in Estonia, to find the most promising species in terms of chemical composition to alleviate BPH. Materials and Methods. The qualitative and quantitative analyses of polyphenols in herbs of Epilobium spp. were performed using HPLC/MS. All five species were collected from the pond's shore in Pilkuse village (Otepää municipality, Valga county, Estonia) in July 2008. Research results. It was found that 20 % ethanol was optimal for extracting polyphenolic compounds from the herb Epilobium spp. with subsequent UV chromatogram analysis at 350 nm. In the analyzed Epilobium species, 12 polyphenolic compounds were identified. Oenothein B, myricetin rhamnoside and myricetin glucoside were the principal polyphenolic compounds among other identified constituents in the Epilobium spp. herbs. E. montanum had the highest content of oenothein B. The highest was the total content of myricetin glycosides for all five compared species, the total content of quercetin glycosides was slightly lower, and the total content of kaempferol glycosides was the lowest. Conclusions. The content of polyphenols is highest in E. adenocaulon and the lowest in E. parviflorum. Thus, E. parviflorum does not offer the best therapeutic potential for the to relief of BPH in terms of the quantitative content of polyphenolic compounds

Antioxidant and Stress Resistance Properties of Flavonoids from Chinese Sea Buckthorn Leaves from the Qinghai-Tibet Plateau.

The unique ecological environment of the Qinghai-Tibetan Plateau has endowed Chinese sea buckthorn leaves with rich bioactivities. In this study, we investigated the bioactivity and stress resistance mechanisms of flavonoids derived from Chinese sea buckthorn leaves (FCL) native to the Qinghai-Tibet Plateau. Our analysis identified a total of 57 flavonoids, mainly flavonol glycosides, from FCL, of which 6 were novel flavonoids. Isorhamnetin glycosides, quercetin glycosides and kaempferol glycosides were the three most dominant classes of compounds in FCL. In particular, isorhamnetin-3-O-glucoside-7-O-rhamnoside emerged as the most abundant compound. Our results showed that FCL possesses potent antioxidant properties, as evidenced by its ability to effectively scavenge DPPH free radicals and demonstrate ferric reducing antioxidant power (FRAP) and oxygen radical absorbance capacity (ORAC) levels comparable to Trolox, a well-known antioxidant standard. Furthermore, FCL showed remarkable efficacy in reducing reactive oxygen species (ROS) levels and malondialdehyde (MDA) levels while enhancing the activities of key antioxidant enzymes, namely superoxide dismutase (SOD) and catalase (CAT), in Caenorhabditis elegans, a widely used model organism. Mechanistically, we elucidated that FCL exerts its stress resistance effects by modulating of transcription factors DAF-16 and HSF-1 within the insulin/insulin-like growth factor-1 signaling pathway (IIS). Activation of these transcription factors orchestrates the expression of downstream target genes including sod-3, ctl-1, hsp16.2, and hsp12.6, thus enhancing the organism's ability to cope with stressors. Overall, our study highlights the rich reservoir of flavonoids in Chinese sea buckthorn leaves as promising candidates for natural medicines, due to their robust antioxidant properties and ability to enhance stress resistance.

Qualitative investigation and screening of antimicrobial activity of stem extract in Clerodendrum infortunatum plant

Clerodendrum infortunatum is known as hill glory bower and a plant which is widely distributed throughout the whole world. Up to now, many species of C. infortunatum have been described in various indigenous systems of medicine that are used in preparation of folklore medicines for the treatment of various life-threatening diseases, and much of this plant have been very well studied for their chemical constituents and biological activities. It also is used in Unani, Ayurveda, and siddha system of medicine for many years. From Clerodendrum infortunatum many compounds, including mono-turpentine and its derivatives, sesquiterpene, diterpenoids, tri-terpentine, flavonoid, quercetin, acacetin, gallic acid, sterol and flavonoid glycoside, phenylethanoid glycoside, steroids and steroid glycosides, cyclohexylethanoids, anthraqunine, cyanogenic glycolsides, and others have been isolated and identified. In the present study, Chloroform, pet. ether, and water stem extract of Clerodendrum infortunatum obtained by Soxhlet extraction was screened to detect the presence or absence of several bioactive compounds which are reported to cure different diseases. Anti-microbial analysis of stem extract was carried out against lactobacillus, E.coli and staphylococcus aureus organisms by agar well diffusion method. It was observed that the zone was recorded against this organism. The results indicate that the chloroform, pet.ether and water extracts of C. infortunatum are having anti- microbial efficiency in controlling the microorganisms. So, Clerodendrum infortunatum is the plant which are beneficial on human health.

Comparing antioxidant and cytoprotective effects: Quercetin glycoside vs. aglycone from Ephedra alata

BackgroundA wide range of chronic diseases is associated with ROS-mediated oxidative stress. Quercetin glycoside (QG) is reported to be a powerful antioxidant with extremely high bioavailability and structural stability compared to quercetin aglycone. Hypothesis/PurposeIn this study, the antioxidant potential and cytoprotective effects of quercetin, and its glycosides isolated from Ephedra alata against oxidative damage induced by hydrogen peroxide in the cells of tetrahymena pyriformis (TEP) were evaluated and compared. Study designQuercetin and its O-glycosides were isolated from Ephedra alata, and their chemical structures were elucidated using advanced spectroscopic techniques. The antioxidant and cytoprotective effects were evaluated using TEP cells exposed to hydrogen peroxide-induced oxidative stress. MethodsTEP cells were pretreated with quercetin aglycone (Q), isoquercetin (ISQ), or hyperin (HYP) before exposure to hydrogen peroxide (H2O2). Cell viability, lactate dehydrogenase (LDH) release, intracellular ROS levels, malondialdehyde (MDA levels, lipoperoxidation, antioxidant enzyme activity, and cleaved caspase-3 levels were measured. ResultsISQ pretreatment significantly enhanced cell survival and reduced H2O2-induced LDH release compared to Q. ISQ also decreased intracellular ROS levels, MDA levels, and lipoperoxidation, surpassing the effects of Q. Additionally, ISQ and HYP pretreatment notably increased antioxidant enzyme activity, outperforming Q. Furthermore, ISQ pretreatment significantly diminished cleaved caspase-3 levels compared to Q, indicating a potential role in preventing oxidative stress-induced apoptosis in TEP cells. ConclusionQuercetin O-glycosides, particularly isoquercetin, from Ephedra alata exhibit superior antioxidant and cytoprotective effects compared to quercetin aglycone. These findings highlight the potential of these compounds as natural alternatives for mitigating oxidative damage and promoting cellular health. Future research should focus on elucidating the precise molecular pathways involved and evaluating their efficacy in animal models and clinical settings.

A synchronized, large-scale field experiment using Arabidopsis thaliana reveals the significance of the UV-B photoreceptor UVR8 under natural conditions.

This study determines the functional role of the plant ultraviolet-B radiation (UV-B) photoreceptor, UV RESISTANCE LOCUS 8 (UVR8) under natural conditions using a large-scale 'synchronized-genetic-perturbation-field-experiment'. Laboratory experiments have demonstrated a role for UVR8 in UV-B responses but do not reflect the complexity of outdoor conditions where 'genotype × environment' interactions can mask laboratory-observed responses. Arabidopsis thaliana knockout mutant, uvr8-7, and the corresponding Wassilewskija wild type, were sown outdoors on the same date at 21 locations across Europe, ranging from 39°N to 67°N latitude. Growth and climatic data were monitored until bolting. At the onset of bolting, rosette size, dry weight, and phenolics and glucosinolates were quantified. The uvr8-7 mutant developed a larger rosette and contained less kaempferol glycosides, quercetin glycosides and hydroxycinnamic acid derivatives than the wild type across all locations, demonstrating a role for UVR8 under field conditions. UV effects on rosette size and kaempferol glycoside content were UVR8 dependent, but independent of latitude. In contrast, differences between wild type and uvr8-7 in total quercetin glycosides, and the quercetin-to-kaempferol ratio decreased with increasing latitude, that is, a more variable UV response. Thus, the large-scale synchronized approach applied demonstrates a location-dependent functional role of UVR8 under natural conditions.

Unveiling biotransformation of free flavonoids into phenolic acids and Chromones alongside dynamic migration of bound Phenolics in Lactobacillus-fermented lychee pulp

Lactobacillus strains have emerged as promising probiotics for enhancing the bioactivities of plant-based foods associated with flavonoid biotransformation. Employing microbial fermentation and mass spectrometry, we explored flavonoid metabolism in lychee pulp fermented separately by Lactiplantibacillus plantarum and Limosilactobacillus fermentum. Two novel metabolites, 3,5,7-trihydroxychromone and catechol, were exclusively identified in L. plantarum-fermented pulp. Concomitant with consumption of catechin and quercetin glycosides, dihydroquercetin glycosides, 2,4-dihydroxybenzoic acid and p-hydroxyphenyllactic acid were synthesized by two strains through hydrogenation and fission of C-ring. Quantitative analysis revealed that bound phenolics were primarily located in water-insoluble polysaccharides in lychee pulp. Quercetin 3-O-rutinoside was partially liberated from water-insoluble polysaccharides and migrated to water-soluble polysaccharides during fermentation. Meanwhile, substantial accumulations in short-chain fatty acids (increased 1.45 to 3.08-fold) and viable strains (increased by 1.97 to 2.00 Log10 CFU/mL) were observed in fermentative pulp. These findings provide broader insight into microbial biotransformation of phenolics and possible guidance for personalized nutrition.

Diplotaxis Genus: A Promising Source of Compounds with Nutritional and Biological Properties.

Research on bioactive compounds is essential to improve human health; promote adequate nutrition; drive innovation in the food, agricultural and biotechnology industries; and contribute to the preservation of the environment. The genus Diplotaxis (Brassicaceae) currently comprises around forty species, some of which are edible, particularly Diplotaxis tenuifolia (wild rocket), Diplotaxis erucoides (wall rocket), Diplotaxis muralis (annual wall rocket), Diplotaxis viminea (perennial wall rocket), and Diplotaxis simplex. The leaves of these species are rich in fiber and essential minerals, such as calcium, iron, potassium, and magnesium. Thirteen species have been characterized for their phenolic compounds, predominantly kaempferol, quercetin, and isorhamnetin glycosides. Furthermore, glucosinolate compounds were identified in nineteen species of the genus Diplotaxis. Many of the phytochemicals identified in Diplotaxis spp. demonstrated interesting biological activities, such as antioxidant, anti-inflammatory, antibacterial, hypoglycemic and hypolipidemic effects, as well as cytotoxicity and antiproliferative properties. This article provides a review of the phytochemistry of the Diplotaxis genus, highlighting its importance in food, its biological properties, potential pharmacological applications, and the dearth of research on many of these plants.

Separation, identification, and fingerprinting of antioxidant components in persimmon (Diospyros kaki) leaves by offline two-dimensional liquid chromatography with electrochemical detection and tandem mass spectrometry.

In this work, the antioxidant components in persimmon (Diospyros kaki) leaves were separated by offline two-dimensional liquid chromatography-electrochemical detection (LC×LC-ECD) and identified by LC-tandem mass spectrometry (LC-MS/MS). A total of 33 antioxidants, mainly proanthocyanidins, and glycosides of kaempferol and quercetin, were identified. The antioxidant assays demonstrated that the fractions collected from the first-dimension LC (1D-LC) possessed considerable radical scavenging capabilities, with correlation coefficients of peak area versus radical scavenging capability of 1,1-diphenyl-2-picrylhydrazyl and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) being 0.9335 and 0.9116, respectively. The fingerprinting showed that 37 peaks were present in all samples. The major antioxidant components of persimmon leaves were the glycosides of kaempferol and quercetin. Finally, fourteen antioxidants were quantitatively assessed. Offline LC×LC provided high peak capacity and separation; ECD enabled specific screening and detection of antioxidant components; and MS/MS provided excellent identification capability. In this study, the combination of the three approaches was utilized to screen for antioxidant components in persimmon leaves, with satisfactory findings. In conclusion, this technique is an effective means for rapid analysis of antioxidant components and quality control of medicinal plants, achieving rapid separation of congeners and facilitating more accurate qualitative and quantitative analyses.