Who Is the King? Theα-Hydroxy-β-oxo-α,β-enone Moiety or the Catechol B Ring: Relationship between the Structure of Quercetin Derivatives and Their Pro-Oxidative Abilities

2010 ◽  
Vol 7 (1) ◽  
pp. 236-244 ◽  
Author(s):  
Pei-Yan Liu ◽  
Kun Li ◽  
Ji Zhang ◽  
Da-Wei Zhang ◽  
Hong-Hui Lin ◽  
...  
Keyword(s):  
Quercetin Derivatives

scholarly journals Effect of Hydrolysable Tannins and Anthocyanins on Recurrent Urinary Tract Infections in Nephropathic Patients: Preliminary Data

Nutrients ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 591 ◽  
Author(s):  
Annalisa Noce ◽  
Francesca Di Daniele ◽  
Margherita Campo ◽  
Manuela Di Lauro ◽  
Anna Pietroboni Zaitseva ◽  
...  
Keyword(s):  
Urinary Tract ◽  
Urinary Tract Infections ◽  
Bacterial Flora ◽  
Bioactive Compound ◽  
In Vitro Tests ◽  
Bacterial Strains ◽  
Quercetin Derivatives ◽  
Hydrolysable Tannins ◽  
Tract Infections

Urinary tract infections (UTIs) are caused by uropathogenic microorganism colonization. UTIs often require an antibiotic therapy that can cause the selection of antibiotic-resistant bacterial strains. A natural bioactive compound may represent a valid therapeutic adjuvant approach, in combination with drug therapy. In this paper, we present a pilot study, based on the administration of an oral food supplement (OFS), containing chestnut tannins and anthocyanins, to nephropathic patients suffering from recurrent UTIs (16 treated patients with 1 cp/day and 10 untreated patients). We performed laboratory tests and quality of life and body composition assessments, at T0 (baseline) and T1 (after 6 weeks OFS assumption). The analysis of OFS was performed by HPLC-DAD-MS for its content in polyphenols and by in vitro tests for its antioxidative and anti-free radical activities. In each capsule, polyphenol content was 6.21 mg (4.57 mg hydrolysable tannins, 0.94 mg anthocyanosides, 0.51 mg proanthocyanidins, 0.18 mg quercetin derivatives). A significant reduction of erythrocyte sedimentation rate was observed only in male patients. Urinalysis showed a significant reduction of leukocytes in both genders, whereas urinary bacterial flora at T1 significantly decreased only in male subjects. Tannins seem to exert an antimicrobial action according to gender, useful to counteract the recurrence of UTIs.

scholarly journals Influence of Cooking Methods on Onion Phenolic Compounds Bioaccessibility

Foods ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 1023
Author(s):  
Alice Cattivelli ◽  
Angela Conte ◽  
Serena Martini ◽  
Davide Tagliazucchi
Keyword(s):  
Phenolic Compounds ◽  
In Vitro Digestion ◽  
Total Phenolic ◽  
Cooking Methods ◽  
Total Phenolic Compounds ◽  
Main Compound ◽  
Quercetin Derivatives ◽  
Mass Spectrometry Identification ◽  
The Impact

The impact of domestic cooking (baking, boiling, frying and grilling) and in vitro digestion on the stability and release of phenolic compounds from yellow-skinned (YSO) and red-skinned onions (RSO) have been evaluated. The mass spectrometry identification pointed out flavonols as the most representative phenolic class, led by quercetin-derivatives. RSO contained almost the double amount of phenolic compounds respect to YSO (50.12 and 27.42 mg/100 g, respectively). Baking, grilling and primarily frying resulted in an increased amount of total phenolic compounds, especially quercetin-derivatives, in both the onion varieties. Some treatments promoted the degradation of quercetin-3-O-hexoside-4′-O-hexoside, the main compound present in both the onion varieties, leading to the occurrence of quercetin-4′-O-hexoside and protocatechuic acid-4-O-hexoside. After in vitro digestion, the bioaccessibility index for total phenolic compounds ranged between 42.6% and 65.5% in grilled and baked YSO, respectively, and between 39.8% and 80.2% in boiled and baked RSO, respectively. Baking contributed to the highest amount of bioaccessible phenolic compounds for both the onion varieties after in vitro digestion. An in-depth design of the cooking process may be of paramount importance in modulating the gastro-intestinal release of onion phenolic compounds.

scholarly journals Development of a Rapid UHPLC-PDA Method for the Simultaneous Quantification of Flavonol Contents in Onions (Allium cepa L.)

2021 ◽  
Vol 14 (4) ◽  
pp. 310
Author(s):  
Ana V. González-de-Peredo ◽  
Mercedes Vázquez-Espinosa ◽  
Ceferino Carrera ◽  
Estrella Espada-Bellido ◽  
Marta Ferreiro-González ◽  
...  
Keyword(s):  
High Performance ◽  
Desirability Function ◽  
Radical Scavenging ◽  
Complete Separation ◽  
Raw Material ◽  
Antioxidant Compounds ◽  
Protective Effects ◽  
Quercetin Derivatives ◽  
Allium Cepa L ◽  
Successful Separation

Onion, one of the most consumed vegetables in the world, is also known to contain high levels of antioxidant compounds, with protective effects against different degenerative pathologies. Specifically, onion is rich in flavonols, mainly quercetin derivatives, which are compounds with high antioxidant and free radical scavenging power. For this reason, it is of the utmost importance to count on optimal analytical methods that allow for the determination and quantification of these compounds of interest. A rapid ultra-high performance liquid chromatography (UHPLC)-photo-diode array (PDA) method for the separation of the major flavonols in onions was developed using a Box–Behnken design in conjunction with multiresponse optimization on the basis of the desirability function. The conditions that provided a successful separation were 9.9% and 53.2% of phase B at the beginning and at the end of the gradient, respectively; 55 °C column working temperature; and 0.6 mL min−1 flow rate. The complete separation was achieved in less than 2.7 min with excellent chromatographic characteristics. The method was validated, and its high precision, low detection and quantification limits, good linearity, and robustness were confirmed. The correct applicability of the method improves the analysis of the raw material, increasing the quality of onions and its subproducts in terms of bioactive compounds and functional characteristics for consumers.

Design, synthesis and pharmacological evaluation of ester-based quercetin derivatives as selective vascular KCa1.1 channel stimulators

2020 ◽  
Vol 105 ◽  
pp. 104404
Author(s):  
Gabriele Carullo ◽  
Amer Ahmed ◽  
Alfonso Trezza ◽  
Ottavia Spiga ◽  
Antonella Brizzi ◽  
...  
Keyword(s):  
Design Synthesis ◽  
Quercetin Derivatives ◽  
Pharmacological Evaluation

UPLC-MS for Identification of Quercetin Derivatives in Cuphea glutinosa Cham. & Schltdl (Lythraceae) and Evaluation of Antifungal Potential

2018 ◽  
Vol 14 (6) ◽  
pp. 586-594 ◽  
Author(s):  
MarI C. Santos ◽  
Lidiane S. Farias ◽  
Liara Merlugo ◽  
Thayse V. de Oliveira ◽  
Fabio S. Barbosa ◽  
...  
Keyword(s):  
Quercetin Derivatives ◽  
Antifungal Potential

scholarly journals Podophyllotoxin and Quercetin in Silico Derivatives Docking Analysis with Cyclooxygenase-2 and Aminopeptidase-N

2021 ◽  
Author(s):  
A.E. Manukyan ◽  
A.A. Hovhannisyan
Keyword(s):  
In Silico ◽  
Biological Activities ◽  
Three Dimensional ◽  
Aminopeptidase N ◽  
Docking Analysis ◽  
Quercetin Derivatives ◽  
Pubchem Database ◽  
A Cell ◽  
Cox 2 ◽  
High Level

ABSTRACTThe cyclooxygenase (COX) enzymes are tumor markers, the inhibition of which can be used in the prevention and therapy of carcinogenesis. It was found that COX-2 IS considered as targets for tumor inhibition. Aminopeptidase N (APN) is a type II membrane-bound metalloprotease associated with cancer, being identified as a cell marker on the surface of malignant myeloid cells and reached a high level of expression in progressive tumors. In anticancer therapy, plant compounds are considered that can inhibit their activity. Modeling of the COX-2 and APN enzymes was carried out on the basis of molecular models of three-dimensional structures from the PDB database [PDB ID: 5f19, 4fyq] RCSB. For docking analysis, 3D ligand models were created using MarvinSketch based on the PubChem database [CID: 5280343, 5281654]. In silico experiments, for the first time, revealed the possible interaction and inhibition of COX-2 and APN by quercetin and quercetin derivatives. Aspirin and Marimastat were taken to compare the results. Possible biological activities and possible side effects of the ligands have been identified.

scholarly journals Bioactive Compounds of Selected Fruit Juices

2009 ◽  
Vol 4 (5) ◽  
pp. 1934578X0900400 ◽  
Author(s):  
Aneta Wojdyłto ◽  
Jan Oszmiański
Keyword(s):  
Antioxidant Activity ◽  
Phenolic Compounds ◽  
Fruit Juice ◽  
Biological Activities ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Sea Buckthorn ◽  
Quercetin Derivatives ◽  
Reducing Ability ◽  
Wide Range

Fruits are one of the most important sources of phenolic compounds in our diet. Many of these compounds exhibit a wide range of biological activities, especially antioxidant activity. The objective of this study was to determine the composition and antioxidant activity of phenolic compounds found in fruit juice obtained from buckthorn, flowering quince, rowanberry and hawthorn. Hydroxycinnamic acids (neochlorogenic and chlorogenic acid) and procyanidins were the main phenolics in rowanberry juice. The highest level of flavonols (quercetin derivatives) was found in sea buckthorn. All juices showed strong free-radical scavenging activity against ABTS•+ radicals and ferric reducing ability measured by the FRAP method. The strongest antioxidant activity was found in rowanberry juice, but the lowest was measured in hawthorn and sea buckthorn juices.

scholarly journals A Polyphenol-Rich Fraction from Eugenia uniflora Exhibits Antioxidant and Hepatoprotective Activities In Vivo

2020 ◽  
Vol 13 (5) ◽  
pp. 84
Author(s):  
Mansour Sobeh ◽  
Marwa S. Hamza ◽  
Mohamed L. Ashour ◽  
Mona Elkhatieb ◽  
Mohamed A El Raey ◽  
...  
Keyword(s):  
Carbon Tetrachloride ◽  
Liver Injury ◽  
Ethyl Acetate ◽  
Acute Liver Injury ◽  
Antioxidant Activities ◽  
Biological Effects ◽  
Ethyl Acetate Fraction ◽  
Eugenia Uniflora ◽  
Quercetin Derivatives

Leaves from Eugenia uniflora, the red Brazilian cherry, have a high content of flavonoids that possess several biological effects such as anti-inflammatory, antioxidant, and antidiabetic activities. However, their influence on carbon tetrachloride (CCl4)-induced acute liver injury in rats has not been investigated. In the current study, a bioguided fractionation assay revealed that the ethyl acetate fraction (EAF) of Eugenia uniflora is the safest and most active fraction. LC-MS analysis of the ethyl acetate fraction revealed 22 secondary metabolites, mainly myricetin and quercetin derivatives. EAF did not show toxicity up to 2000 mg/kg, and exhibited antioxidant activities in vitro in DPPH assay with IC50 of 3.35 µg/mL. Additionally, EAF exhibited substantial antioxidant activities in vivo by counteracting the oxidative damage of the prooxidant juglone [80 µM] in Caenorhabditis elegans model organism and increased its survival rate in a dose-dependent fashion through the DAF-16/Foxo pathway. Furthermore, the hepatoprotective activity of EAF (200 mg/kg against carbon tetrachloride (CCl4) intoxicated male Wistar rats was assessed. EAF significantly inhibited CCl4-induced elevation of alanine aminotransferase (ALT), aspartate transaminase (AST), total bilirubin (TB), total cholesterol (TC), and triglycerides (TG), in the blood serum and prevented lipid peroxidation and restored superoxide dismutase (SOD) activity and glutathione (GSH) content in liver tissues. The observed hepatoprotective effects of EAF, which were supported by histopathological observations as pretreatment with EAF, effectively attenuated the CCl4-induced histopathological changes. In conclusion, EAF of Eugenia uniflora leaves has substantial hepatoprotective activities against CCl4 induced acute liver injury in rats due to its antioxidant activity.

scholarly journals HPLC Analysis of Kaempherol and Quercetin Derivatives Isolated by Different Extraction Techniques from Plant Matrix

2011 ◽  
Vol 94 (1) ◽  
pp. 17-21 ◽  
Author(s):  
Krystyna Skalicka-Woźniak ◽  
Janusz Szypowski ◽  
Kazimierz Głowniak
Keyword(s):  
Hplc Analysis ◽  
Soxhlet Extraction ◽  
Array Detector ◽  
Extraction Techniques ◽  
Ultrasound Extraction ◽  
Quercetin Derivatives ◽  
Rp Hplc ◽  
Photodiode Array Detector ◽  
Photodiode Array

Abstract Soxhlet extraction, ultrasound extraction, and accelerated solvent extraction (ASE), followed by RP-HPLC with a photodiode array detector was used for the determination of flavonoids in fruits of Peucedanum alsaticum. Three compounds were identified: a kaempherol derivative (astragalin), and two quercetin derivatives (quercitrin and hiperoside). The highest extraction yields of the selected compounds were obtained by use of exhaustive ASE.

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