scholarly journals Phenolic Compounds in Tea: Phytochemical, Biological, and Therapeutic Applications

2021 ◽  
Author(s):  
Jyoti V. Vastrad ◽  
Pratikhya Badanayak ◽  
Giridhar Goudar

Phenolic compounds are one of the major and most complex groups of phytochemicals found among plant kingdom. Structurally they comprise of aromatic ring along with one or more hydroxyl groups. Based on the structure they are divided into subgroups such as phenolic acids, flavonoids, tannins, coumarins, lignans, quinones, stilbenes and carotenoids. Plant polyphenols are gaining popularity as a result of their potent antioxidant properties and notable effects in the prevention of oxidative stress-related diseases. Extraction, identification and characterisation of phenolic compounds from various plant sources has become a major area of health and medical research in the recent years. The major bioactive compounds responsible for tea’s health benefits are thought to be phenolics. Catechin derivatives make up the majority of the phenolic compounds found in tea, and though flavonols and phenolic acids are also present in smaller amounts. The bioactivity of the compounds has been linked to a lower risk of serious illnesses like cancer, cardiovascular disease, and neurodegenerative disease. This chapter covers phenolic extraction, purification, analysis and quantification, as well as their antioxidant properties in different varieties of tea leaves.

Foods ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1206 ◽  
Author(s):  
Hafiz A. R. Suleria ◽  
Colin J. Barrow ◽  
Frank R. Dunshea

Fruit peels have a diverse range of phytochemicals including carotenoids, vitamins, dietary fibres, and phenolic compounds, some with remarkable antioxidant properties. Nevertheless, the comprehensive screening and characterization of the complex array of phenolic compounds in different fruit peels is limited. This study aimed to determine the polyphenol content and their antioxidant potential in twenty different fruit peel samples in an ethanolic extraction, including their comprehensive characterization and quantification using the LC-MS/MS and HPLC. The obtained results showed that the mango peel exhibited the highest phenolic content for TPC (27.51 ± 0.63 mg GAE/g) and TFC (1.75 ± 0.08 mg QE/g), while the TTC (9.01 ± 0.20 mg CE/g) was slightly higher in the avocado peel than mango peel (8.99 ± 0.13 mg CE/g). In terms of antioxidant potential, the grapefruit peel had the highest radical scavenging capacities for the DPPH (9.17 ± 0.19 mg AAE/g), ABTS (10.79 ± 0.56 mg AAE/g), ferric reducing capacity in FRAP (9.22 ± 0.25 mg AA/g), and total antioxidant capacity, TAC (8.77 ± 0.34 mg AAE/g) compared to other fruit peel samples. The application of LC-ESI-QTOF-MS/MS tentatively identified and characterized a total of 176 phenolics, including phenolic acids (49), flavonoids (86), lignans (11), stilbene (5) and other polyphenols (25) in all twenty peel samples. From HPLC-PDA quantification, the mango peel sample showed significantly higher phenolic content, particularly for phenolic acids (gallic acid, 14.5 ± 0.4 mg/g) and flavonoids (quercetin, 11.9 ± 0.4 mg/g), as compared to other fruit peel samples. These results highlight the importance of fruit peels as a potential source of polyphenols. This study provides supportive information for the utilization of different phenolic rich fruit peels as ingredients in food, feed, and nutraceutical products.


Molecules ◽  
2019 ◽  
Vol 24 (7) ◽  
pp. 1262 ◽  
Author(s):  
Anna Oniszczuk ◽  
Kamila Kasprzak ◽  
Agnieszka Wójtowicz ◽  
Tomasz Oniszczuk ◽  
Marta Olech

Buckwheat is a generous source of phenolic compounds, vitamins and essential amino acids. This paper discusses the procedure of obtaining innovative gluten-free, precooked pastas from roasted buckwheat grains flour, a fertile source of natural antioxidants, among them, phenolic acids. The authors also determined the effect of the extruder screw speed and the level of moisture content in the raw material on the quantity of free phenolic acids. The qualitative and quantitative analysis of phenolic acids in pasta was carried out using high-performance liquid chromatography electrospray ionization tandem mass spectrometry (HPLC-ESI-MS/MS). The chromatographic method was validated. For extracts with the highest total content of free phenolic acids and unprocessed flour from roasted buckwheat grain, the TLC-DPPH test was also performed to determine the antioxidant properties of the tested pasta. The level of moisture in the raw material had an impact on the content of phenolic acids. All pastas made from buckwheat flour moistened up to 32% exhibited a higher total content of free phenolic acids than other mixes moistened to 30 and 34% of water.


Molecules ◽  
2020 ◽  
Vol 25 (19) ◽  
pp. 4371
Author(s):  
Weronika Adach ◽  
Jerzy Żuchowski ◽  
Barbara Moniuszko-Szajwaj ◽  
Malgorzata Szumacher-Strabel ◽  
Anna Stochmal ◽  
...  

Background: The Paulownia Clone in Vitro 112, known as oxytree or oxygen tree, is a hybrid clone of the species Paulownia elongata and Paulownia fortunei (Paulowniaceae). The oxytree is a fast-growing hybrid cultivar that can adapt to wide variations in edaphic and climate conditions. In this work, Paulownia Clone in Vitro 112 leaves were separated into an extract and four fractions (A–D) differing in chemical content in order to investigate their chemical content using LC-MS analysis. The extract and fractions were also evaluated for their anticoagulant and antioxidant properties in a human plasma in vitro. Results: The Paulownia leaf extract contained mainly phenolic compounds (e.g., verbascoside), small amounts of iridoids (e.g., aucubin or 7-hydroxytometoside) and triterpenoids (e.g., maslinic acid) were also detected. Our results indicate that the extract and fractions have different effects on oxidative stress in human plasma treated with H2O2/Fe in vitro, which could be attributed to differences in their chemical content. For example, the extract and all the fractions, at the two highest concentrations of 10 and 50 µg/mL, significantly inhibited the plasma lipid peroxidation induced by H2O2/Fe. Fractions C and D, at all tested concentrations (1–50 µg/mL) were also found to protect plasma proteins against H2O2/Fe-induced carbonylation. The positive effects of fraction C and D were dependent on the dose. Conclusions: The extract and all four fractions, but particularly fractions C and D, which are rich in phenolic compounds, are novel sources of antioxidants, with an inhibitory effect on oxidative stress in human plasma in vitro. Additionally, the antioxidant potential of fraction D may be associated with triterpenoids.


Biomolecules ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1266
Author(s):  
Noelia Carballeda Sangiao ◽  
Susana Chamorro ◽  
Sonia de Pascual-Teresa ◽  
Luis Goya

Cocoa is a rich source of polyphenols, especially flavanols and procyanidin oligomers, with antioxidant properties, providing protection against oxidation and nitration. Cocoa phenolic compounds are usually extracted with methanol/ethanol solvents in order to obtain most of their bioactive compounds; however, aqueous extraction seems more representative of the physiological conditions. In this study, an aqueous extract of cocoa powder has been prepared and chemically characterized, and its potential protective effect against chemically-induced oxidative stress has been tested in differentiated human neuroblastoma SH-SY5Y cells. Neuronal-like cultured cells were pretreated with realistic concentrations of cocoa extract and its major monomeric flavanol component, epicatechin, and then submitted to oxidative stress induced by a potent pro-oxidant. After one hour, production of reactive oxygen species was evaluated by two different methods, flow cytometry and in situ fluorescence by a microplate reader. Simultaneously, reduced glutathione and antioxidant defense enzymes glutathione peroxidase and glutathione reductase were determined and the results used for a comparative analysis of both ROS (reactive oxygen species) methods and to test the chemo-protective effect of the bioactive products on neuronal-like cells. The results of this approach, never tested before, validate both analysis of ROS and indicate that concentrations of an aqueous extract of cocoa phenolics and epicatechin within a physiological range confer a significant protection against oxidative insult to neuronal-like cells in culture.


2019 ◽  
Vol 78 (2) ◽  
pp. 175-180
Author(s):  
Martina Persic ◽  
Robert Veberic ◽  
Maja Mikulic-Petkovsek

Abstract Extracts from quince leaves are a well-known home remedy used for treating diverse health problems. Most of the beneficial properties of quince leaf extracts may be assigned to their high content of phenolic compounds, particularly tannins. In this research, we have evaluated the efficiency of various methods for phenolic extraction from quince leaves and determined detailed phenolic profiles of different extracts. The results indicated that leaf drying is a suitable pretreatment for enhancing the extraction of phenolic compounds. Higher extraction of phenolics was achieved at higher temperatures (i.e. infusion or decoction). Phenolic profiles of quince leaf extracts differed among the extraction solvents and time of extraction. Flavanols prevailed in extracts obtained by decoction and ethanolic maceration, while extracts obtained by maceration in water and infusion were rich in phenolic acids. A highly concentrated quince leaf extract was attained by ethanolic maceration, using a standard ratio of solvent and leaf material.


2011 ◽  
Vol 20 (No. 1) ◽  
pp. 15-22 ◽  
Author(s):  
a. Troszyńska ◽  
e. Ciska

The purpose of this study was to compare the composition and contents of phenolic acids and condensed tannin in the seed coats of white and coloured varieties of pea and to examine the antioxidant properties of methanol and acetone extracts containing these phenolic compounds. The contents of phenolic acids were quantified by the HPLC analysis. The sum of free phenolic acids, those liberated from soluble esters and those liberated from soluble glycosides, was higher for coloured seed coat (78.53 g per g dry matter) than for the white seed coat (17.17 g/g dry matter). Protocatechuic, gentisic and vanillic acids were found dominant in the coloured seed coat, while ferulic and coumaric acids in the white seed coat. The content of condensed tannins was 1560 mg of catechin equivalent/100 g of coloured seed coat as determined by a vanillin assay. No condensed tannins were detected in the white seed coat. The antioxidant activity of extracts was measured by the oxidation of phosphatidylcholine to hydroxyperoxidephosphatidyl choline in the liposome system. Strong antioxidant properties were observed in a crude tannin extract from the coloured seed coat. These properties were slightly changed after the seed coat was cooked in water for 30, 60 and 90 min.  


2019 ◽  
Vol 24 (40) ◽  
pp. 4800-4806 ◽  
Author(s):  
Mario F. Neves ◽  
Michelle R. Cunha ◽  
Tainah de Paula

Background: In recent years, it has become more evident that oxidative stress is involved in the development of cardiovascular disease. Indeed, reactive oxygen species seems to be the common mechanism for endothelial dysfunction, vascular inflammation and arterial stiffness, resulting in a blood pressure increase and early vascular aging. Methods: This review presents the potential role of antioxidant nutrients and exercise for cardiovascular protection. Results: Flavonoids, vitamins and minerals present in some fruits and foliage are considered natural antioxidants. In fact, fruits and vegetables contain large amounts of antioxidants. Several clinical trials have extensively studied vitamin E, beta-carotene, vitamin C, polyphenols, plus selenium and zinc. In addition, many authors have been carried out clinical trials to evaluate the mechanisms of oxidative stress attenuation after exercise. Exercise responses may vary according to the Frequency, Intensity, Time and Type (FITT) principle, making it difficult to obtain a consensus concerning the exercise properties and redox status. High-intensity interval training (HIIT) has been reported as an efficient option for metabolic adaptations in a short time. Aerobic exercises must be performed at least three times a week, for two months or more, using moderate to vigorous intensity to promote a positive effect on oxidative stress and vascular function. Conclusion: The recognition of appropriate nutrients and exercise with antioxidant properties may be an important supportive approach to impair early vascular aging and to prevent cardiovascular disease.


2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Urszula Złotek ◽  
Urszula Gawlik-Dziki ◽  
Dariusz Dziki ◽  
Michał Świeca ◽  
Renata Nowak ◽  
...  

The aim of this study was to evaluate the influence of drying temperature on the phenolic acids profile and antioxidant activity of sprouts and leaves red and white Chenopodium quinoa (RQ and WQ, respectively). Four-day sprouts and leaves dried at 30, 45, and 60°C were tested. All sprouts contained significant amounts of phenolic compounds; however, higher content was determined in the RQ sprouts. Phenolic compounds from WQ sprouts seem to be thermostable in the studied temperature range, whereas total phenolics content in RQ sprouts decreased significantly after drying in the 60°C. Content of vanillic and p-coumaric acids did not differ significantly between sprouts dried at the same conditions; however, their level decreased in the high temperature. Irrespective of the drying temperature, higher activity against ABTS free radicals and reducing power was observed in the case of RQ sprouts extracts. Sprouts dried at 30°C had a higher ability to scavenge hydroxyl radicals. RQ sprouts were characterized by about two times higher antioxidant activity regardless of the method used. No significant differences between total phenolics (TPC) and flavonoids content in RQ and LQ leaves were found. In the both cases, decrease of TPC was observed after drying in the highest temperature. The leaves do not differ too much in terms of the phenolic acids profile, whereas the differentiating factor is thermal processing. Leaves of both quinoa contained thermostable compounds able to scavenge hydroxyl radicals. Reducing power and ability to scavenge OH radicals were correlated with all components of quinoa sprouts which suggest synergism between them and does not indicate the key role of a particular compound in creating antioxidant capacity. Germination and subsequent oven-drying at 30°C of quinoa seeds significantly increased the antioxidant properties compared with raw seeds. Also, in the case of leaves, the best results were obtained after drying at 30°C.


Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1517
Author(s):  
Sofia M. Gutierrez-Zetina ◽  
Susana González-Manzano ◽  
Begoña Ayuda-Durán ◽  
Celestino Santos-Buelga ◽  
Ana M. González-Paramás

Caffeic and dihydrocaffeic acid are relevant microbial catabolites, being described as products from the degradation of different phenolic compounds i.e., hydroxycinnamoyl derivatives, anthocyanins or flavonols. Furthermore, caffeic acid is found both in free and esterified forms in many fruits and in high concentrations in coffee. These phenolic acids may be responsible for a part of the bioactivity associated with the intake of phenolic compounds. With the aim of progressing in the knowledge of the health effects and mechanisms of action of dietary phenolics, the model nematode Caenorhabditis elegans has been used to evaluate the influence of caffeic and dihydrocaffeic acids on lifespan and the oxidative stress resistance. The involvement of different genes and transcription factors related to longevity and stress resistance in the response to these phenolic acids has also been explored. Caffeic acid (CA, 200 μM) and dihydrocaffeic acid (DHCA, 300 μM) induced an increase in the survival rate of C. elegans under thermal stress. Both compounds also increased the mean and maximum lifespan of the nematode, compared to untreated worms. In general, treatment with these acids led to a reduction in intracellular ROS concentrations, although not always significant. Results of gene expression studies conducted by RT-qPCR showed that the favorable effects of CA and DHCA on oxidative stress and longevity involve the activation of several genes related to insulin/IGF-1 pathway, such as daf-16, daf-18, hsf-1 and sod-3, as well as a sirtuin gene (sir-2.1).


2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Mindaugas Liaudanskas ◽  
Loreta Kubilienė ◽  
Vaidotas Žvikas ◽  
Sonata Trumbeckaitė

In recent years, particular attention has been paid to the natural antioxidants. Bee products, especially propolis, are characterized by multifunctional (antioxidant, anti-inflammatory, antibacterial, antiviral, and food preservative) effects and can be used for the development of functional food or food preservatives. Propolis extracts that are commonly produced are ethanolic; therefore, to certain groups of consumers, for example, children and alcohol sensitive group, their applicability is limited. The aim of this study was to develop alternative propolis from aqueous-polyethylenglycolic propolis extract (AQUA-PEG) and compare the chemical composition as well as antioxidant (radical-scavenging and reduction properties) activities to those of ethanolic propolis extract (EEP). Polyethylene glycol is quite a good solvent, which can be successfully used for the preparation of NEP. The total quantity of phenolic compounds identified in AQUA-PEG (400.36 µg/mL), prepared according to our technology, is very similar to that of EEP (433.53 µg/mL), whereas the amount of phenolic acids was greater by 1.31-fold in AQUA-PEG and of flavonoids was greater by 2.38-fold in EEP. The antioxidant activity depends on the method used: by applying the ABTS and CUPRAC methods, both extracts demonstrate similar antioxidant (antiradical and reducing) activity, whereas in the case of the DPPH and FRAP method, significantly higher antioxidant activity was detected in EEP. This should be taken by researchers into account especially when interpreting the results and drawing conclusions about the antioxidant activity of propolis extracts. On the basis of the results, AQUA-PEG, prepared by the developed technology, can be used as an alternative form to ethanolic propolis extract, since it contains a large quantity of antioxidants, namely, flavonoids and phenolic acids. We believe that nonethanolic propolis extract has the prospect of being applied for the development of functional foods in order to alleviate certain symptoms of oxidative stress or for the prevention of some oxidative-stress-related diseases.


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