Novel Oxidative Dimer from Caffeic Acid

Background: The consumption of antioxidants, including phenolic compounds, is considered important for preventing the oxidative damage diseases and ageing. The total polyphenol content (TPC) is the parameter used to estimate the quality of plant-derived products. Methods: Phenol oxidase activity of green bean (Phaseolus vulgaris) crude extract (in the presence of hydrogen peroxide) and banana (Musa sp.) pulp crude extract has been studied spectrophotometrically using catechol, gallic acid, caffeic acid, ferulic acid, and quercetin as substrates. All studied compounds have been oxidized in the presence of green bean crude extract and hydrogen peroxide; all studied compounds except ferulic acid have been oxidized in the presence of banana pulp crude extract. Michaelis constants (Km) and maximum reaction rates (Vmax) have been determined for oxidation in the presence of green bean crude extract and hydrogen peroxide (Km are 3.8×10-4 M, 1.6×10-3 M, 2.2×10-4 M, 2.3×10-4 M, 1.4×10-4 M and Vmax are 0.046 min-1, 0.102 min-1, 0.185 min-1, 0.053 min-1, 0.041 min-1 for catechol, gallic acid, caffeic acid, ferulic acid, and quercetin, respectively) and for oxidation in the presence of banana pulp crude extract (Km are 1.6×10-3 M, 3.8×10-3 M, 2.2×10-3 M, 4.2×10-4 M and Vmax are 0.058 min-1, 0.025 min-1, 0.027 min-1, 0.015 min-1 for catechol, gallic acid, caffeic acid, and quercetin, respectively). The influence of 3-methyl-2-benzothiazolinone hydrazone (MBTH) on the oxidation reactions kinetics has been studied: Michaelis constants values decrease and maximum reaction rates increase, which contributes to the increase in sensitivity of the determination. Results: Kinetic procedures of Total Polyphenol Content (TPC) determination using crude plants extracts in the presence of MBTH have been proposed (time of analysis is 1 min). For gallic acid (used as a standard for TPC determination) detection limit is 5.3×10-5 M, quantitation limit is 1.8×10-4 M, and linear range is 1.8×10-4 - 1.3×10-3 M for green bean crude extract; detection limit is 2.9×10-5 M, quantitation limit is 9.5×10-5 M, and linear range is 9.5×10-5 - 2.4×10-3 M for banana pulp crude extract. Proposed procedures are characterized by higher interference thresholds for sulfites, ascorbic acid, and citric acid compared to pure enzymes (horseradish peroxidase and mushroom tyrosinase) in the same conditions. Compared with standard Folin-Ciocalteu (FC) method the procedures described in this work are also characterized by less interference and more rapid determination. Conclusion: The procedures have been applied to TPC determination in tea, coffee, and wine samples. The results agree with the FC method for tea and coffee samples and are lower for wine samples, probably, due to sulfites interference.

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Characterization of Solid Lipid Nanoparticles Containing Caffeic Acid and Determination of its Effects on MCF-7 Cells

Recent Patents on Anti-Cancer Drug Discovery ◽

10.2174/1574892810666150115124413 ◽

2015 ◽

Vol 10 (2) ◽

pp. 224-232 ◽

Cited By ~ 5

Author(s):

Gokhan Dikmen ◽

Gamze Guney ◽

Lutfi Genc

Keyword(s):

Caffeic Acid ◽

Solid Lipid Nanoparticles ◽

Lipid Nanoparticles ◽

Solid Lipid ◽

Mcf 7

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Ultrasonic-assisted synthesis of nickel tungstate nanoparticles on poly (3,4-ethylene dioxythiophene):poly (4-styrene sulfonate) for the effective electrochemical detection of caffeic acid

Materials Today Communications ◽

10.1016/j.mtcomm.2020.101833 ◽

2020 ◽

pp. 101833

Author(s):

Vivekanandan Alangadu Kothandan ◽

Sivakumar Mani ◽

Shen-ming Chen ◽

Shih-Hsun Chen

Keyword(s):

Caffeic Acid ◽

Electrochemical Detection ◽

Styrene Sulfonate ◽

Ultrasonic Assisted

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A Simple Method for Evaluating the Bioactive Phenolic Compounds’ Presence in Brazilian Craft Beers

Molecules ◽

10.3390/molecules26164716 ◽

2021 ◽

Vol 26 (16) ◽

pp. 4716

Author(s):

Marcelo Coelho Silva ◽

Jeancarlo Pereira dos Anjos ◽

Lilian Lefol Nani Guarieiro ◽

Bruna A. Souza Machado

Keyword(s):

Phenolic Compounds ◽

Caffeic Acid ◽

Good Accuracy ◽

Limit Of Detection ◽

Coumaric Acid ◽

Simple Method ◽

Craft Beer ◽

Extraction Step ◽

Satisfactory Precision ◽

Craft Beers

There are a significant number of analytical methodologies employing different techniques to determine phenolic compounds in beverages. However, these methods employ long sample preparation processes and great time consumption. The aim of this paper was the development of a simple method for evaluating the phenolic compounds’ presence in Brazilian craft beers without a previous extraction step. Catechin, caffeic acid, epicatechin, p-coumaric acid, hydrated rutin, trans-ferulic acid, quercetin, kaempferol, and formononetin were analyzed in fifteen different craft beers. The method showed good linearity (R2 ≥ 0.9966). The limit of detection ranged from 0.08 to 0.83 mg L−1, and limits of quantification were between 0.27 and 2.78 mg L−1. The method showed a satisfactory precision (RSD ≤ 16.2%). A good accuracy was obtained by the proposed method for all phenolic compounds in craft beer (68.6% ˂ accuracy ˂ 112%). Catechin showed higher concentrations (up to 124.8 mg L−1) in the samples, followed by epicatechin (up to 51.1 mg L−1) and caffeic acid (up to 8.13 mg L−1). Rutin and formononetin were observed in all analyzed samples (0.52 mg L−1 to 2.40 mg L−1), and kaempferol was less present in the samples. The presence of plant origin products was determinant for the occurrence of the highest concentrations of phenolic compounds in Brazilian craft beers.

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Relationships Between the Content of Phenolic Compounds and the Antioxidant Activity of Polish Honey Varieties as a Tool for Botanical Discrimination

Molecules ◽

10.3390/molecules26061810 ◽

2021 ◽

Vol 26 (6) ◽

pp. 1810

Author(s):

Monika Kędzierska-Matysek ◽

Małgorzata Stryjecka ◽

Anna Teter ◽

Piotr Skałecki ◽

Piotr Domaradzki ◽

...

Keyword(s):

Principal Component Analysis ◽

Antioxidant Activity ◽

Phenolic Compounds ◽

Caffeic Acid ◽

Principal Component ◽

Total Content ◽

Component Analysis ◽

Total Phenolic ◽

Hydroxybenzoic Acid ◽

Coumaric Acid

The study compared the content of eight phenolic acids and four flavonoids and the antioxidant activity of six Polish varietal honeys. An attempt was also made to determine the correlations between the antioxidant parameters of the honeys and their polyphenol profile using principal component analysis. Total phenolic content (TPC), total flavonoid content (TFC), antioxidant activity (ABTS) and reduction capacity (FRAP) were determined spectrophotometrically, and the phenolic compounds were determined using high-performance liquid chromatography (HPLC). The buckwheat honeys showed the strongest antioxidant activity, most likely because they had the highest concentrations of total phenols, total flavonoids, p-hydroxybenzoic acid, caffeic acid, p-coumaric acid, vanillic acid and chrysin. The principal component analysis (PCA) of the data showed significant relationships between the botanic origin of the honey, the total content of phenolic compounds and flavonoids and the antioxidant activity of the six Polish varietal honeys. The strongest, significant correlations were shown for parameters of antioxidant activity and TPC, TFC, p-hydroxybenzoic acid, caffeic acid and p-coumaric acid. Analysis of four principal components (explaining 86.9% of the total variance), as a classification tool, confirmed the distinctiveness of the Polish honeys in terms of their antioxidant activity and content of phenolic compounds.

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