Search Results (81)

α-L-Rhamnosidase can specifically hydrolyze plant natural glycosides and holds significant potential for biocatalytic applications in functional foods, healthy products, and pharmaceutical industries. Herein, a novel thermophilic and acidophilic α-L-rhamnosidase TsRha from Thermotoga sp. 2812B belonging to glycoside hydrolase family 78 was identified by genome mining and comprehensively characterized by bioinformatics, computer-aided structural analysis, and biochemical characterization. TsRha possesses a domain architecture comprising one catalytic (α/α)₆-barrel domain and four β-sheet domains. TsRha displayed optimal activity at 90 °C and pH 5.0, remarkable thermostability at 80 °C, and considerable tolerance to organic solvents. TsRha exhibited broad substrate selectivity and might efficiently hydrolyze a series of natural flavonoid glycosides with various glycosidic bonds (α-1, α-1, 2, α-1, 6) from different aglycone subgroups (flavanone, flavone, flavonol, and dihydrochalcone). Moreover, it demonstrated high conversion efficiencies toward a variety of natural flavonoid diglycosides rutin, naringin, naringin dihydrochalcone, hesperidin, and troxerutin, achieving ≥99.1% conversion within 20~100 min. The excellent properties including high activity, thermophilicity, acidophilicity, good thermostability, broad substrate spectrum will make the α-L-rhamnosidase TsRha a promising biocatalyst for the efficient production of rare and high-value flavonoid glucosides with improved bioavailability and bioactivity. Full article

Background: Oxidative stress arises from an imbalance between excessive oxidant production and impaired antioxidant defense systems. This imbalance leads to biomolecular damage, contributing to aging and age-related diseases such as chronic kidney disease (CKD). Oxidative stress is a well-established risk factor for CKD and has been reported to accelerate disease progression. Hesperidin, a flavanone glycoside abundant in citrus fruits, exhibits antioxidant, anti-hypertensive, and anti-inflammatory properties and has been suggested to attenuate CKD progression. However, its potential role in reversing oxidative damage in kidney cells remains unclear. Methods: This study aimed to investigate whether hesperidin can reverse oxidative damage in human kidney proximal tubular epithelial (HK-2) cells. Oxidative stress was induced by exposing HK-2 cells to 500 μM hydrogen peroxide (H₂O₂) for 6 h, followed by treatment with 100 μM hesperidin for 24 h. Results: Our results showed that hesperidin significantly ameliorated H₂O₂-induced cytotoxicity. In the hesperidin post-treatment group (H₂O₂ + hesperidin), the expression of the antioxidant gene manganese superoxide dismutase (MnSOD) and the longevity-associated gene sirtuin 1 (SIRT1) was upregulated, while the expression of the senescence-associated gene β-galactosidase was downregulated compared to the H₂O₂-only treatment. Conclusions: These findings suggest that hesperidin promotes recovery from oxidative injury in kidney cells by enhancing antioxidant and longevity pathways and reducing cellular senescence. This may contribute to improved renal health and potentially slow CKD progression in patients suffering from oxidative stress-related kidney damage. Full article

This paper provides a comprehensive phytochemical analysis of extracts obtained from the leaves and roots of Hedysarum semenowii using HPLC/PDA-ESI-QToF/MS-MS techniques. The study identified 53 compounds, with flavones and isoflavones as the primary polyphenols. Notably, flavones were predominant in the leaves, while isoflavones were found mainly in the roots, potentially serving as chemotaxonomic markers. Medicarpin and its glucoside were confirmed in the roots, while mangiferin and its derivatives were identified for the first time in both the roots and leaves. Isoflavones like formononetin, calycosin, and afrormosin, along with their glucosides, were exclusive to the roots. Flavonols such as quercetin and its glycosides were abundant in the aboveground parts. Our study also identified flavones like luteolin, flavanones (naringenin), and chalcones (liquiritigenin) in various parts. Additionally, the phenolic acids gallic and ferulic acids, as well as the organic acids malic and citric acid, were also detected. The extracts demonstrated differential antimicrobial and antifungal activities in a microbroth dilution assay, with the aerial part extracts showing superior efficacy, particularly against Staphylococcus epidermidis and Pseudomonas aeruginosa. Both aerial and underground parts exhibited comparable antifungal activity against Candida species. Antioxidant activity in the 1,1-diphenyl-2-picrylhydrazyl (DPPH^•) radical scavenging test varied significantly, with ethanolic extracts from the aerial parts showing the highest potential (Antioxidant Activity Index (AAI) 2.07 ± 0.13). In contrast, root extracts had consistently low antioxidant activity. The results highlight the aerial parts of H. semenowii as a more promising source of biologically active compounds with antimicrobial and antioxidant properties compared to the roots. Full article

Artemisia dracunculus L., commonly known as tarragon, is a popular culinary herb and a valuable source of bioactive extracts and phytocompounds. Its wide distribution across regions of the Northern Hemisphere demonstrates the species’ high adaptability to diverse growing conditions and has led to the development of chemoraces that differ in chemical composition. North Asian populations of A. dracunculus remain poorly studied, and plants growing in Siberia have not yet been examined. Given the vast areas occupied by tarragon, the species is a promising candidate for industrial use. Liquid chromatography–mass spectrometry (LC–MS) profiling identified 80 compounds in Siberian tarragon samples, including hydroxycinnamates (HCys), coumarins, flavonoid aglycones (FlAs), and glycosides (FlGs). Among these, 62 phenolics were reported for the first time as A. dracunculus metabolites, highlighting the uniqueness of the North Asian accessions, particularly in their diversity of flavone O-glycosides and methylated flavanone aglycones. The highest levels of HCy, FlA, and FlG were 21.84, 52.53, and 54.44 mg/g, respectively, yielding a total phenolic content of 128.81 mg/g in the dry plant material—a high value. The concentrations of certain compounds exceeded 1%, making tarragon a noteworthy source of rare metabolites, including naringenin 7-O-methyl ester, thermopsoside, tilianin, and naringenin 7,4′-di-O-methyl ester. Thus, the existing knowledge of the chemical profile of tarragon has been expanded by new data on phenolic compounds from the North Asian populations of the species, which may be used to develop new A. dracunculus varieties with improved metabolic profiles and bioactive properties. Full article

This study explores the synthesis of chlorine-substituted flavanones and their biotechnologically derived glycosides in order to evaluate how structural modifications influence both antimicrobial activity and pharmacokinetic properties, with attention to issues such as solubility and membrane transport. Four chloroflavanones (2′-, 3′-, 4′-, and 6-chloroflavanone) were synthesized and biotransformed using entomopathogenic fungi to obtain glycosylated derivatives. Antimicrobial activity was assessed against five microbial strains, while pharmacokinetic properties were predicted computationally. Results showed that 4′-chloroflavanone demonstrated the strongest antimicrobial activity, particularly against Gram-positive bacteria Staphylococcus aureus ATCC 29213 and Enterococcus faecalis ATCC 19433. Most compounds unexpectedly promoted Escherichia coli ATCC 25922 growth, except 4′-chloroflavanone and 3′-chloroflavanone 6-O-β-D-(4″-O-methyl)-glucopyranoside. Nearly all compounds exhibited antifungal activity against Candida albicans ATCC 10231. Glycosylation generally reduced antimicrobial potency but improved water solubility and in silico predictions indicate markedly reduced blood–brain barrier permeation and potential P-glycoprotein recognition. Selective chlorine substitution combined with biotechnological glycosylation may offer a route to antimicrobial flavonoids with improved aqueous solubility and favorable predicted pharmacokinetics. Full article

Neohesperidin (NH), a bioactive flavanone glycoside, exhibits multifaceted pharmacological properties including antioxidant and anti-inflammatory activities. However, its clinical application is severely constrained by inherent physicochemical limitations such as poor aqueous solubility and instability under physiological conditions. To address these challenges, this study developed a dual-carrier nano-liposomal system through the synergistic integration of phospholipid complexation and hydroxypropyl-β-cyclodextrin (HP-β-CD) inclusion technologies. Two formulations—NH-PC (phospholipid complex) and NH-PC-CD (phospholipid/HP-β-CD hybrid)—were fabricated via ultrasonication-assisted ethanol precipitation. Comprehensive characterization using FTIR and PXRD confirmed the amorphous dispersion of NH within lipid bilayers, with complete elimination of crystalline diffraction peaks, indicative of molecular-level interactions between NH’s hydroxyl groups and phospholipid polar moieties. The engineered nanosystems demonstrated remarkable solubility enhancement, achieving 321.77 μg/mL (NH-PC) and 318.75 μg/mL (NH-PC-CD), representing 2.01- and 1.99-fold increases over free NH. Encapsulation efficiencies exceeded 95% for both formulations, with sustained release profiles revealing 60.81% (NH-PC) and 80.78% (NH-PC-CD) cumulative release over 72 h, governed predominantly by non-Fickian diffusion kinetics. In vitro gastrointestinal simulations highlighted superior bioaccessibility for NH-PC-CD (66.35%) compared to NH-PC (58.52%) and free NH (20.85%), attributed to enhanced stability against enzymatic degradation. Storage stability assessments further validated the robustness of HP-β-CD-modified liposomes, with NH-PC-CD maintaining consistent particle size (<3% variation) and encapsulation efficiency (>92%) over 30 days. Antioxidant evaluations demonstrated concentration-dependent DPPH radical scavenging, wherein nanoencapsulation significantly amplified NH’s activity compared to its free form. This study establishes a paradigm for dual-functional nanocarriers, offering a scalable strategy to optimize the delivery of hydrophobic nutraceuticals while addressing critical challenges in bioavailability and physiological stability. Full article

Objectives: The aim of this study was to provide a comprehensive overview of the nutritional and toxicological aspects of different forms of blueberry products (fresh blueberries, dried blueberries, supplements and herbal teas). Methods: Twelve aglycone and glycoside polyphenolic compounds, such as stilbenoids (resveratrol, astringin), flavonols (quercetin, rutin, isoquercitrin, quercitrin, kaempferol), flavanols (catechin, epicatechin), flavanone (hesperitin), flavone (luteolin), and forty chemical elements were analyzed using high-performance liquid chromatography coupled to a mass spectrometer and inductively coupled plasma mass spectrometry. Total phenolic and flavonoid content and antioxidant activity were also evaluated. Results: Different distributions of polyphenolic compounds were observed in the blueberry samples, with quercetin and its derivatives, as well as catechin and epicatechin, present in all samples. High concentrations of Ca, K, Mg and P (10–5800 mg/kg) were detected, followed by Fe and Mn at levels below the allowable limits in foods (425 and 500 mg/kg, respectively). The daily intake of polyphenols was quantified, and the estimated daily intake (EDI) was calculated for sixteen elements (including As, Cd, Cu, Fe, Ni, Pb, V and Zn). Hazard quotients (HQs), hazard index (HI) and cancer risk (CR) were assessed for carcinogenic and non-carcinogenic risks associated with the EDI of these elements in food products for both adults and young consumers. For all samples, HI values were below 1, and CR values were within acceptable limits. Conclusions: The diversity in polyphenolic profiles and elemental content in blueberry-based products was highlighted by this exploratory study. These findings are valuable for understanding the health benefits and risks of blueberry products. Full article

A sustainable alternative to replace the use of toxic and non-biodegradable conventional solvents for the extraction of active principles from plants is natural deep eutectic solvents (NADESs). Larrea cuneifolia Cav. (Zygophyllaceae) is a plant widely distributed in semiarid areas of western Argentina. Several studies validate its popular medicinal use by demonstrating its biological activities such as antibacterial, antifungal, antioxidant, anti-inflammatory, and anticarcinogenic properties, among others. The aim of this work was to compare the bioactive compounds and the in vitro antioxidant and antibacterial activity of L. cuneifolia extracts using non-conventional vs. conventional solvents. Aqueous, ethanolic, and four NADES extracts were prepared. The extracts were phytochemically characterized, and extracted compounds were identified by UHPLC-MS/MS. Antioxidant activity was determined by evaluating the hydrogen peroxide and free radical scavenging capacity using ABTS^•+. The antibacterial activity of the extracts and NADESs was evaluated against Gram-positive and Gram-negative multidrug-resistant strains. The extracts of L. cuneifolia presented a variable content of total phenolic compounds between 4163.4 and 24,371.63 µg GAE/mL. Phenolic acids, flavonoid glycosides, flavanones, flavones, flavonols, alkaloids, lignans (nordihydroguaiaretic acid and its derivatives), and other compounds were tentatively identified in extracts of L. cuneifolia obtained with conventional and non-conventional solvents. A heatmap cluster and a bubble plot were created to compare the diversity and relative abundance of identified compounds, and the extracts were classified into two major groups. All extracts were able to scavenge > 40% of hydrogen peroxide and the ABTS radical cation (ABTS^•+) (CD₅₀ = 3.15–5.13 µg GAE/mL). The LAS extract exhibited the highest bacterial growth inhibition (MIC = 75–37.5 µg GAE/mL). In conclusion, the results show that NADESs represent a sustainable alternative for the extraction of compounds with antioxidant and antibacterial activity and could therefore replace traditional solvents in the pharmaceutical, cosmetic, or food industries. Full article

α-L-rhamnosidases play a key role in the metabolism and biodegradation of dietary flavonoid glycosides. We have developed a novel microplate spectrophotometric method to rapidly evaluate the conversion rates and substrate selectivities of mesophilic α-L-rhamnosidases towards citrus flavanone diglycosides by combining with a high-active and thermophilic β-D-glucosidase based on UV-visible spectral differences between citrus flavanone diglycosides and the corresponding aglycones under alkaline conditions. Furthermore, catalytic activities and enzyme kinetics of four α-L-rhamnosidases from human gut bacteria on various dietary flavonoid glycosides with different glycosidic bonds from various subclasses have been explored by HPLC. The α-L-rhamnosidase BtRha78A specifically removed the rhamnose group from the flavones, flavanones and flavonols diglycosides with the α-1,6 glycosidic bonds. Moreover, BtRha78A displayed higher catalytic activities on the rutinose group at 7-OH of the aglycones than at 3-OH. HFM-RhaA preferred to catalyze the flavones, flavanones and dihydrochalcones diglycosides with the α-1,2 glycosidic linkages at the 7-OH. However, this enzyme also showed high catalytic activity on the flavonol diglycoside rutin with the α-1,6 glycosidic bonds at the 3-OH. HFM-RhaC exhibited certain hydrolytic abilities towards all flavonoid diglycosides, and displayed higher activities on the flavonoid diglycosides with the α-1,6 glycosidic bonds. HFM-Rha78 weakly hydrolyzed the flavones, flavanones and dihydrochalcones diglycosides with the α-1,2 glycosidic bonds, and the flavonols diglycosides with α-1,6 glycosidic bonds. All four α-L-rhamnosidases from human gut bacteria did not exhibit catalytic activity towards the flavonoid glycosides with the α-1 glycosidic bonds. It was revealed that the α-L-rhamnosidases from human gut bacteria possessed diverse substrate selectivity on dietary flavonoid diglycosides. The structural basis for the specificity of BtRha78A on the flavonoid diglycosides with α-1,6 glycosidic bonds and the preference of HFM-RhaA on the flavonoid diglycosides with α-1,2 glycosidic bonds have been analyzed by molecular docking. Full article

Hypoxic damage to retinal pigment epithelial (RPE) cells and subsequent neovascularization are key factors in the pathogenesis of branch retinal vein occlusion (BRVO). Naringin (NG), a naturally occurring flavanone glycoside, has demonstrated significant antioxidant and anti-neovascular activities. However, the regulatory effects and mechanisms of NG on ferroptosis in BRVO are yet to be explored. Our study aimed to investigate the protective effects of NG on RPE cells under hypoxic stress and to elucidate the underlying molecular mechanisms. Our findings revealed that NG significantly reduced cytotoxicity induced by cobaltous chloride (CoCl₂) and also inhibited vascular proliferation in the retina, thereby attenuating choroidal neovascularization. NG pretreatment largely countered the overproduction of reactive oxygen species (ROS) and malondialdehyde (MDA) triggered by hypoxic damage, while also restoring levels of the antioxidants glutathione (GSH) and superoxide dismutase (SOD). Furthermore, NG pretreatment significantly activated the expression of hypoxia-inducible factor-1 alpha (HIF-1α) and its downstream heme oxygenase-1 (HO-1) and NADPH dehydrogenase (NQO1). In conclusion, NG not only inhibits neovascularization but also alleviates inflammation in RPE cells by modulating the HO-1/GPX4 pathway to inhibit ferroptosis. These findings highlight the potential of NG as a promising therapeutic agent for the treatment of BRVO. Full article

Previous research has consistently shown that high-fat diet (HFD) consumption can lead to the development of colonic inflammation. Neohesperidin (NHP), a naturally occurring flavanone glycoside in citrus fruits, has anti-inflammatory properties. However, the efficacy and mechanism of NHP in countering prolonged HFD-induced inflammation remains unclear. In this study, rats on HFD were intragastrically administered (i.g.) with NHP for 12 consecutive weeks. Results indicate that this natural compound is effective in reducing colorectal inflammation at doses of 40–80 mg/kg body weight (BW) by i.g. administration, with significant decreases in inflammation markers such as TNF-α and IL-1β levels. It also improved intestinal mucosal tissue integrity and reduced HFD-stimulated colorectal inflammation via the JAK2/STAT3 pathway. Furthermore, intestinal microbiota sequencing results show that NHP intervention significantly downregulated the Firmicutes/Bacteroidetes ratio. This ratio is closely related to the preventive role in the context of glycolipid metabolism disorder. Compared with fecal cultures of rats from the HFD group, after 48 h in vitro fermentation, those from the NHP group had distinct microbiota composition and notably higher concentrations of SCFAs. Collectively, these observations suggest that 80 mg/kg BW NHP possesses biological activities in downregulating HFD-induced colorectal inflammation by regulating intestinal flora and promoting SCFAs formation. Full article

A novel and efficient analytical protocol based on paper spray tandem mass spectrometry was developed for the determination of isomeric O-glycoside flavanones in citrus juices and beverages. This approach significantly reduces sample preparation time and solvent consumption compared to traditional chromatographic techniques. By exploiting the unique fragmentation patterns of these compounds, accurate quantification of both diglycosides and their individual isomers (neohesperidoside and rutinose derivatives) was achieved. The method demonstrated excellent analytical performance, with high accuracy, selectivity, and reproducibility. The impact of matrix effects was mitigated through the construction of ratio calibration curves, ensuring reliable quantification in complex matrices. Finally, a simple DPPH experiment to assay the antioxidant activity of each single positional isomer was performed, indicating the superior ability of neohesperidose conjugates. This simplified method offers a valuable tool for quality control, authenticity assessment and the study of health benefits associated with citrus consumption. Full article

Xanthohumol (1) is a major prenylated flavonoid in hops (Humulus lupulus L.) which exhibits a broad spectrum of health-promoting and therapeutic activities, including anti-inflammatory, antioxidant, antimicrobial, and anticancer effects. However, due to its lipophilic nature, it is poorly soluble in water and barely absorbed from the gastrointestinal tract, which greatly limits its therapeutic potential. One method of increasing the solubility of active compounds is their conjugation to polar molecules, such as sugars. Sugar moiety introduced into the flavonoid molecule significantly increases polarity, which results in better water solubility and often leads to greater bioavailability. Entomopathogenic fungi are well known for their ability to catalyze O-glycosylation reactions. Therefore, we investigated the ability of selected entomopathogenic filamentous fungi to biotransform xanthohumol (1). As a result of the experiments, one aglycone (2) and five glycosides (3–7) were obtained. The obtained (2″E)-4″-hydroxyxanthohumol 4′-O-β-D-(4‴-O-methyl)-glucopyranoside (5) has never been described in the literature so far. Interestingly, in addition to the expected glycosylation reactions, the tested fungi also catalyzed chalcone–flavanone cyclization reactions, which demonstrates chalcone isomerase-like activity, an enzyme typically found in plants. All these findings undoubtedly indicate that entomopathogenic filamentous fungi are still an underexploited pool of novel enzymes. Full article

Pelargonium graveolens L’Hèr. (Geraniaceae) is renowned for its traditional use as a flavor, ornamental and medicinal plant. This work aimed at an in-depth study of the phytochemical profiling and in vitro antioxidant and enzyme inhibition assessment of a methanol-aqueous extract from P. graveolens leaves. A UHPLC-HRMS analysis revealed more than 110 secondary metabolites, including 8 acyltartaric and 11 acylcitric/acylisocitric acids; 8 gallotannins; 36 flavonols, flavanones and methoxylated flavonoids together with 17 phenolic and aliphatic acids; and 21 phenolic acid glycosides. For the first time, acylcitric acids along with feruloyl- and coumaroyltartaric acids are reported in the species. The leaf extract actively scavenged 2,2-diphenyl-1-picrylhydrazyl DPPH (273.45 mg trolox equivalent (TE/g)) and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS^•+) radicals (531.97 mgTE/g) and showed a high reducing power: 431.32 mg TE/g Cupric reducing antioxidant capacity (CUPRAC) and 292.21 mg TE/g Ferric reducing antioxidant power (FRAP). It possessed a metal chelating capacity (13.44 ethylenediaminetetraacetic acid equivalent (EDTAE)/g) and contained 2.71 mmol TE/g in the phosphomolybdenum assay. The rose geranium extract exhibited high inhibition towards acetyl- and butyrylcholinesterase (2.80 and 2.20 mg galantamine equivalent (GALAE)/g, respectively) and tyrosinase (75.49 mg kojic acid equivalent (KAE)/g). It inhibited α-glucosidase and α-amylase (3.75 mmol and 0.79 acarbose equivalent (ACAE)/g, respectively) and lipase (28.91 mg orlistat equivalent (OE)/g). This study sheds light into the future potential application of the rose geranium in pharmaceutical and nutraceutical products. Full article

Senna rugosa is a species found in the Cerrado and used in folk medicine as a vermifuge and in the treatment of poisonous snakebites accidents. In this work, we identified the main secondary metabolites present in ethanolic extracts of the leaves (ELSR) and roots (ERSR) of S. rugosa and evaluated the potential cytoprotective effect against cellular macromolecular damage, as well as the cytotoxic properties of the extracts on the K562 and Jurkat leukemic cell lines. The identification of metabolites was carried out by liquid chromatography coupled with mass spectrometry. The antioxidant activities were investigated by direct ABTS^•+ and DPPH^• radical scavenging methods, protection against oxidative damage in proteins, and DNA. Cytotoxic properties were investigated against healthy cells, isolated from human peripheral blood (PBMC) and leukemic cell lines. The leaf extracts contained catechin, rutin, epigallocatechin derivatives, kaempferol glycosides, luteolin, and dimeric and trimeric procyanidins, while the root extract profile showed obtusichromoneside derivatives, 2-methoxystypandrone, stilbene derivatives, naphthopyranones, and flavanone derivatives. The extracts showed antioxidant activity, with an IC₅₀ of 4.86 ± 0.51 μg/mL and 8.33 ± 0.90 μg/mL in the ABTS assay for ELSR and ERSR, respectively. Furthermore, in the DPPH^• assay, the IC₅₀ was 19.98 ± 1.96 μg/mL for ELSR and 13.37 ± 1.05 μg/mL for ERSR. The extracts protected macromolecules against oxidative damage at concentrations of 5 μg/mL. The cytotoxicity test against leukemic strains was observed after 24 and 48 h of treatment. After 48 h, results against the K562 cell line demonstrate an IC₅₀ of 242.54 ± 2.38 μg/mL and 223.00 ± 2.34 μg/mL for ELSR and ERSR, respectively. While against the Jurkat cell line, these extracts showed an IC₅₀ of 171.45 ± 2.25 μg/mL and 189.30 ± 2.27 μg/mL, respectively. The results pertaining to PBMC viability demonstrated that the extracts showed selectivity for the leukemic cell lines. Together, our results reveal that the leaves and roots of S. rugosa have completely distinct and complex chemical compositions and expand their significant pharmacological potential in oxidative stress and leukemia conditions. Full article