scholarly journals Coumaroyl Flavonol Glycosides and More in Marketed Green Teas: An Intrinsic Value beyond Much-Lauded Catechins

Molecules ◽  
2020 ◽  
Vol 25 (8) ◽  
pp. 1765 ◽  
Author(s):  
Lorenzo Candela ◽  
Marialuisa Formato ◽  
Giuseppina Crescente ◽  
Simona Piccolella ◽  
Severina Pacifico

Marketed green teas (GTs) can highly vary in their chemical composition, due to different origins, processing methods, and a lack of standardization of GT-based products. Consequently, biological activities become difficult to correlate to the presence/content of certain constituents. Herein, ultra-high-performance liquid chromatography (UHPLC) combined with high-resolution tandem mass spectrometry (HR MS/MS) was successfully applied to six commercial GT products, extracted by ethanol sonication, to disclose their polyphenol profile beyond the well-known catechins. The relative abundance of each class of metabolites was correlated to antiradical and antilipoperoxidant data through hierarchical clustering analysis, since it reasonably affects the beneficial properties of the product that reaches the consumer. The thiobarbituric acid reactive substances (TBARS) assay demonstrated that GT extracts effectively counteracted the UV-induced lipoperoxidation of hemp oil, which is highly rich in Polyunsaturated Fatty Acids (PUFAs), and therefore highly unstable. The Relative Antioxidant Capacity Index (RACI) comprehensively emphasized that gunpower and blend in filter GTs appeared to be the less active matrices, and except for a GT-based supplement, the Sencha GT, which was particularly rich in flavonol glycosides, was the most active, followed by Bancha GT.

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Lamia Kerbouche ◽  
Mohamed Hazzit ◽  
Aoumeur Baaliouamer ◽  
Soraya Akretche

AbstractThe essential oils (EOs) of Origanum floribundum Munby, an aromatic and medicinal plant endemic in Algeria, were extracted by different hydrodistillation times (30 min, 1, 2 and 3 h) and analyzed by GC and GC–MS. The chromatographic analysis showed that thymol (32.7–45.0%), p-cymene (16.8–23.1%) and γ-terpinene (21.6–28.7%) were the most prominent components of the oils. The antioxidant ability was measured using the reductive potential, thiobarbituric acid reactive substances (TBARS) assay and the inhibition of free radicals DPPH● and ABTS●+. Antibacterial activity was assessed by the disc diffusion method against three bacteria (Escherichia coli, Staphylococcus aureus and Bacillus subtilis) and one fungus (Candida albicans). Minimal inhibitory concentrations (MICs) were determined using a microdilution method. Thymol is one of the compounds of EOs, which are widely reported as very biologically active. Although the oil isolated for 30 min was the less-thymol rich, it was the most active with all the antioxidant tests. In the most cases, the antimicrobial activity showed the best results with oils isolated for 30 min and 3 h (MIC = 0.25–1.75 μL/mL). These results suggest that it might be possible to isolate the EO from this plant for a minimum distillation time to obtain oil that can give maximum biological activities.


Author(s):  
GABRIELA ELISA HIRSCH ◽  
MÁRCIA VIZZOTTO ◽  
ANA LUCIA ABOY ◽  
AMÉLIA TEREZINHA HENRIQUES ◽  
TATIANA EMANUELLI

The antioxidant activity and bioactive compounds of different blackberry fruit genotypes from the major Brazilian producer region (three cultivars and four selections) were evaluated and compared to the Cherokee cultivar. Phenolic and anthocyanic extracts were obtained and evaluated for each fruit genotype. The phenolic extracts of selections 02/96 and 07/001 presented higher antioxidant activity than those of cultivars in most assays. This activity was partially correlated to the higher amount of total phenolics in these samples. Thus, the phenolic compounds are probably the major responsible for the antioxidant activity in the diphenyl-2-picrylhydrazyl radical scavenging assay (DPPH), ferric reducing antioxidant power (FRAP) assay and thiobarbituric acid reactive substances (TBARS) assay. Quercetin seems to be responsible for the antioxidant activity of blackberry phenolic extracts in the β-carotene bleaching assay. Concerning anthocyanic extracts, the selection 02/96 and Cherokee cultivar from harvest 2007 had higher antioxidant activity than the other genotypes in most assays. Anthocyanins appear to be the major responsible for the antioxidant activity of anthocyanic extracts in the DPPH and FRAP assays, although ascorbic acid also contributed to the DPPH antioxidant activity. Selection 02/96 appears to have higher antioxidant activity than the commercial cultivars cultivated in the southern Brazil and appears to be promising for nutritional and health purposes.


2011 ◽  
Vol 21 (2) ◽  
pp. 153-158 ◽  
Author(s):  
James H. Chappell ◽  
Marc Alan Cohn

AbstractLipid peroxidation and membrane damage are often proposed as causes of recalcitrant seed death, and the thiobarbituric acid reactive substances (TBARS) assay is commonly used to measure lipid peroxidation. However, several artefacts can cause an overestimation of TBARS values, and these have not been routinely addressed in experiments with recalcitrant seeds. In the present report, TBARS was assayed as recalcitrantSpartina alternifloraand orthodoxS. pectinataseeds were dried rapidly. Using the traditional Heath and Packer (1968) protocol with tissue extraction at 4°C,S. alterniflorahad higher overall TBARS values thanS. pectinata, and TBARS products increased when recalcitrantS. alternifloraand orthodoxS. pectinataseeds were dried. However, when corrections for interfering substances, such as sugars and anthocyanins, were made, the TBARS values between the two species were almost identical. When seeds were freeze-clamped in liquid nitrogen prior to extraction, TBARS did not increase during desiccation for either species. These findings may indicate that lipid peroxidation is not the cause of desiccation-induced death inS. alterniflora. Therefore, freeze-clamping during tissue extraction and corrections for TBARS interfering substances must be applied to avoid overestimation of lipid peroxidation values.


Molecules ◽  
2020 ◽  
Vol 25 (13) ◽  
pp. 3074
Author(s):  
Jeong Yoon Kim ◽  
Yan Wang ◽  
Zuo Peng Li ◽  
Aizhamal Baiseitova ◽  
Yeong Jun Ban ◽  
...  

Xanthine oxidase is a frontier enzyme to produce oxidants, which leads to inflammation in the blood. Prenylated isoflavones from Flemingia philippinensis were found to display potent inhibition against xanthine oxidase (XO). All isolates (1–9) inhibited XO enzyme with IC50 ranging 7.8~36.4 μM. The most active isoflavones (2–5, IC50 = 7.8~14.8 μM) have the structural feature of a catechol motif in B-ring. Inhibitory behaviors were disclosed as a mixed type I mode of inhibition with KI < KIS. Binding affinities to XO enzyme were evaluated. Fluorescence quenching effects agreed with inhibitory potencies (IC50s). The compounds (2–5) also showed potent anti-LDL oxidation effects in the thiobarbituric acid-reactive substances (TBARS) assay, the lag time of conjugated diene formation, relative electrophoretic mobility (REM), and fragmentation of apoB-100 on copper-mediated LDL oxidation. The compound 4 protected LDL oxidation with 0.7 μM in TBARS assay, which was 40-fold more active than genistein (IC50 = 30.4 μM).


2011 ◽  
Vol 64 (7-8) ◽  
pp. 377-380 ◽  
Author(s):  
Aleksandra Novakov-Mikic ◽  
Snezana Brkic ◽  
Daniela Maric ◽  
Bojan Sekulic ◽  
Aleksandar Cetkovic ◽  
...  

Pre-eclampsia is characterized by increased lipid peroxidation and diminished antioxidant capacity. The aim of the study was to establish concentration of thiobarbituric acid reactive substances as a marker of lipid peroxidation in normal pregnancies and in pregnancies complicated with pre-eclampsia, and to estimate the possibility of using thiobarbituric acid reactive substances as a screening method for development of pre-eclampsia. The study was conducted at the Department of Obstetrics and Gynaecology, Clinical Centre of Vojvodina. The study included 57 singleton pregnancies, gestation >24 weeks, of which 29 were healthy pregnancies and 28 were with pre-eclampsia, defined as systolic arterial pressure of >90 mmHg, diastolic of >145 mmHg, and 24h proteinuria of >300mg. Thiobarbituric acid reactive substances concentrations evaluated by malondialdehyde equivalent standards (OxiSelect? TBARS Assay Kit (malondialdehyde Quantitation), Cell Biolabs? OxiSelect?) showed that oxidative stress was more evident in the group with pre-eclampsia, though not statistically significant (p= 0.107). There was no correlation of thiobarbituric acid reactive substance levels with gestation in either group. The differences between the level of thiobarbituric acid reactive substance concentrations in pre-eclampsia and healthy pregnancies indicate the possibility of using thiobarbituric acid reactive substances as a screening tool for the development of pre-eclampsia. Further studies with larger numbers of patients are needed in order to come to final conclusions.


2010 ◽  
Vol 80 (1) ◽  
pp. 65-73 ◽  
Author(s):  
Pei-Min Chao ◽  
Wan-Hsuan Chen ◽  
Chun-Huei Liao ◽  
Huey-Mei Shaw

Conjugated linoleic acid (CLA) is a collective term for the positional and geometric isomers of a conjugated diene of linoleic acid (C18:2, n-6). The aims of the present study were to evaluate whether levels of hepatic α-tocopherol, α-tocopherol transfer protein (α-TTP), and antioxidant enzymes in mice were affected by a CLA-supplemented diet. C57BL/6 J mice were divided into the CLA and control groups, which were fed, respectively, a 5 % fat diet with or without 1 g/100 g of CLA (1:1 mixture of cis-9, trans-11 and trans-10, cis-12) for four weeks. α-Tocopherol levels in plasma and liver were significantly higher in the CLA group than in the control group. Liver α-TTP levels were also significantly increased in the CLA group, the α-TTP/β-actin ratio being 2.5-fold higher than that in control mice (p<0.01). Thiobarbituric acid-reactive substances were significantly decreased in the CLA group (p<0.01). There were no significant differences between the two groups in levels of three antioxidant enzymes (superoxide dismutase, glutathione peroxidase, and catalase). The accumulation of liver α-tocopherol seen with the CLA diet can be attributed to the antioxidant potential of CLA and the ability of α-TTP induction. The lack of changes in antioxidant enzyme protein levels and the reduced lipid peroxidation in the liver of CLA mice are due to α-tocopherol accumulation.


2020 ◽  
Vol 16 (5) ◽  
pp. 743-748
Author(s):  
Ana R.S. de Oliveira ◽  
Kyria J.C. Cruz ◽  
Jennifer B.S. Morais ◽  
Juliana S. Severo ◽  
Jéssica B. Beserra ◽  
...  

Background: The role of minerals in preventing the generation of oxidative stress in obese individuals has been evaluated. Magnesium is an antioxidant nutrient and a cofactor of enzymes involved in the cell membrane stabilization, attenuating the effects of oxidative stress. Objective: To evaluate the association between magnesium and concentrations of thiobarbituric acid reactive substances (TBARS) in patients with obesity and eutrophic women. Methods: A cross-sectional study was conducted with 73 women, divided into two groups: case group (patients with obesity, n=27) and control group (eutrophic women, n=46). Measurements of body mass index and waist circumference were performed. Dietary magnesium intake was assessed by the three-day food record using the NutWin software. Urinary magnesium concentration was measured by atomic absorption spectrophotometry method. Plasma concentrations of thiobarbituric acid reactive substances (TBARS) were also determined. Results: Mean values of dietary magnesium intake were 161.59 ± 60.04 and 158.73 ± 31.96 for patients with obesity and control group, respectively, with no significant difference between the groups studied (p >0.05). The value of urinary excretion of magnesium was lower than the reference values in both groups, with no significant difference between the groups studied (p >0.05). The plasma concentration of thiobarbituric acid reactive substances was significantly higher in patients with obesity compared to the control group (p <0.001). There was no correlation between levels of magnesium biomarkers and the concentration of TBARS (p >0.05). Conclusion: Patients with obesity showed a reduced dietary magnesium intake which seems to induce hypomagnesuria as a compensatory mechanism. The marker of oxidative stress evaluated in this study was not influenced by magnesium.


2013 ◽  
Vol 8 (5) ◽  
pp. 1934578X1300800 ◽  
Author(s):  
Nadezda I. Kulesh ◽  
Sergey A. Fedoreyev ◽  
Marina V. Veselova ◽  
Natalia P. Mischenko ◽  
Vladimir A. Denisenko ◽  
...  

Seven isoflavonoids, including a new glycoside, (6a R,11a R)-medicarpin-3- O-gentiobioside (6), were isolated from the roots of Maackia amurensis using repeated column chromatography on a Toyopearl HW-50F sorbent and identified by HPLC–PDA–MS, 1H NMR, 13C, 1H–1H COSY, HSQC NMR and HMBC NMR analyses as daidzin (1), genistein-7- O-gentiobioside (2), pseudobaptigenin-7- O-gentiobioside (3), formononetin-7- O-gentiobioside (4), (6a R,11a R)-maackiain-3- O-gentiobioside (5), and 5- O-methylgenistein-7- O-gentiobioside (7). In the model of oxidative stress induced by formalin injection, the isolated isoflavone and pterocarpan glucosides 1-7 were shown to reduce the formation of malondialdehyde (MDA) and other thiobarbituric acid reactive substances (TBARS), as well as glutathione peroxidase (GPO) activity in rats.


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