scholarly journals Synthesis and Antioxidant Activity of Caffeic Acid Derivatives

Molecules ◽  
2018 ◽  
Vol 23 (9) ◽  
pp. 2199 ◽  
Author(s):  
Katarzyna Sidoryk ◽  
Anna Jaromin ◽  
Nina Filipczak ◽  
Piotr Cmoch ◽  
Marcin Cybulski
Keyword(s):  
Organic Chemistry ◽  
Antioxidant Activity ◽  
Caffeic Acid ◽  
Wittig Reaction ◽  
Hydroxyl Group ◽  
Hydroxyl Groups ◽  
Water Medium ◽  
One Pot ◽  
Safe Alternative ◽  
Caffeic Acid Derivatives

A series of caffeic acid derivatives were synthesized via a modified Wittig reaction which is a very important tool in organic chemistry for the construction of unsaturated carbon–carbon bonds. All reactions were performed in water medium at 90 °C. The aqueous Wittig reaction worked best when one unprotected hydroxyl group was present in the phenyl ring. The olefinations in the aqueous conditions were also conducted with good yields in the presence of two unprotected hydroxyl groups. When the number of the hydroxyl groups was increased to three, the reaction yields were worse, and the derivatives 12, 13, and 18 were obtained with 74%, 37%, and 70% yields, respectively. Nevertheless, the Wittig reaction using water as the essential medium is an elegant one-pot synthesis and a greener method, which can be a safe alternative for implementation in organic chemistry. The obtained compounds were tested for their antioxidant activity, and 12, 13, and 18 showed the highest activities. Moreover, all synthesized compounds displayed no cytotoxicity, and can therefore be used in the pharmaceutical or cosmetic industry.

scholarly journals Synthesis and Evaluation of Antioxidant Properties of 2-Substituted Quinazolin-4(3H)-ones

Molecules ◽  
2021 ◽  
Vol 26 (21) ◽  
pp. 6585
Author(s):  
Janez Mravljak ◽  
Lara Slavec ◽  
Martina Hrast ◽  
Matej Sova
Keyword(s):  
Antioxidant Activity ◽  
Phenyl Ring ◽  
Biological Activities ◽  
Antioxidant Properties ◽  
Hydroxyl Group ◽  
Hydroxyl Groups ◽  
Ortho Position ◽  
Dpph Assay ◽  
Metal Chelating ◽  
Methoxy Substituent

Quinazolinones represent an important scaffold in medicinal chemistry with diverse biological activities. Here, two series of 2-substituted quinazolin-4(3H)-ones were synthesized and evaluated for their antioxidant properties using three different methods, namely DPPH, ABTS and TEACCUPRAC, to obtain key information about the structure–antioxidant activity relationships of a diverse set of substituents at position 2 of the main quinazolinone scaffold. Regarding the antioxidant activity, ABTS and TEACCUPRAC assays were more sensitive and gave more reliable results than the DPPH assay. To obtain antioxidant activity of 2-phenylquinazolin-4(3H)-one, the presence of at least one hydroxyl group in addition to the methoxy substituent or the second hydroxyl on the phenyl ring in the ortho or para positions is required. An additional ethylene linker between quinazolinone ring and phenolic substituent, present in the second series (compounds 25a and 25b), leads to increased antioxidant activity. Furthermore, in addition to antioxidant activity, the derivatives with two hydroxyl groups in the ortho position on the phenyl ring exhibited metal-chelating properties. Our study represents a successful use of three different antioxidant activity evaluation methods to define 2-(2,3-dihydroxyphenyl)quinazolin-4(3H)-one 21e as a potent antioxidant with promising metal-chelating properties.

scholarly journals Phytochemical analysis of herbal teas containing caffeic acid

2021 ◽  
Vol 57 (2) ◽  
pp. 76-83
Author(s):  
Mihai TODORAN ◽  
◽  
Liana HANGA ◽  
Daniela BENEDEC ◽  
◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Medicinal Plants ◽  
Caffeic Acid ◽  
Antioxidant Properties ◽  
Radical Scavenging ◽  
Total Content ◽  
Phytochemical Analysis ◽  
Chromatography Method ◽  
Caffeic Acid Derivatives ◽  
Level I

Objectives. The present analysis was to investigate the content of caffeic acid derivatives, antioxidant activity, and the presence of caffeic acid in alcoholic extracts obtained from 16 simple teas from the following medicinal plants: Vaccinium mуrtilluѕ, Camеllia ѕinеnѕiѕ, Coffea arabica, Mеlіssa οffіcіnalіs, Οcіmum basіlіcum, Rοsmarіnus οffіcіnalіs, Salvіa οffіcіnalіs, Ηyssοрus οffіcіnalіs, Αrtеmіsіa absіntһіum, Cynara scοlymus, Calendula officinalis, Cοrіandrum satіvum, Fοеnіculum vulgarе, Carum carvі, Rοsa canіna, Crataеgus mοnοgyna. Materials and methods. The presence of caffeic acid was evaluated using the thin layer chromatography method (TLC). The total content of phenylpropanoids from the medicinal herbs alcoholic extracts was determined using a spectrophotometric method. Outcomes. Results were in the range of 0.046-2.426% caffeic acid derivatives (CAE%). The antioxidant properties were measured using the DPPH radical scavenging mechanism. The results were found to be in the range of 63.93% and 0.38% inhibition level (I%). The greatest antioxidant activity was measured for Camellia sinensis (I = 45.54%), followed by Vaccinium myrtillus (I = 50.289%). Conclusions. In this paper it was shown that these medicinal plants are rich in caffeic acid derivatives with antioxidant action capitalized in the prevention of serious diseases.

scholarly journals Antioxidant activity of some coumarins / Antioxidačná activita niektorých kumarínov

2015 ◽  
Vol 62 (s9) ◽  
pp. 41-45 ◽  
Author(s):  
F. Šeršeň ◽  
M. Lácová
Keyword(s):  
Antioxidant Activity ◽  
Acetic Acid ◽  
Superoxide Anion ◽  
The Other ◽  
Hydroxyl Group ◽  
Hydroxyl Groups ◽  
Coumarin Derivatives ◽  
Antioxidant Effectiveness ◽  
Derivatives Of ◽  
Superoxide Anion Radicals

AbstractNineteen derivatives of coumarin were tested on the scavenging of 2,2-diphenyl-1-picrylhydrazyl, hydroxyl and superoxide anion radicals. It was found that antioxidant activity exhibits only such coumarins that contain hydroxyl groups. The derivatives without hydroxyl group showed very low antioxidant effectiveness or they were ineffective. On the other hand, the greatest antioxidant effectiveness was exhibited by coumarin derivatives that contained hydroxyl groups in 6 or 8 position, whereas the effectiveness of derivatives with one hydroxyl group in 4, 5 or 7 position was very low. Based on scavenging of the above-mentioned radicals, it was found that the most effective scavengers were 7,8-dihydroxy-4-methylcoumarin (i.e. compound that contains two hydroxyl groups in 7 and 8 positions), (7,8-dihydroxy-2-oxo-2H-chromen-4-yl)acetic acid (this compound contains in addition to two hydroxyl groups in 7 and 8 positions also one hydroxyl group in the acidic residue), esculetin (6,7-dihydroxycoumarin) and 6,7-dihydroxy-4-methylcoumarin.

scholarly journals Butylated methyl caffeate: a novel antioxidant

2020 ◽  
Vol 71 (2) ◽  
pp. 352
Author(s):  
Q. Q. Chen ◽  
H. Pasdar ◽  
X. C. Weng
Keyword(s):  
Antioxidant Activity ◽  
Caffeic Acid ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
The Other ◽  
Lipid Phase ◽  
Hydroxyl Groups ◽  
Dpph Radical ◽  
Methyl Caffeate ◽  
Dpph Radical Scavenging

A novel caffeic acid derivative, butylated methyl caffeate (BMC), was synthesized via esterification between butylated caffeic acid (BCA) and methanol. Its antioxidant activity was investigated and compared to TBHQ, caffeic acid (CA), methyl caffeate (MC) and BCA through deep-frying, an oven test in oil-in-water emulsions and DPPH radical scavenging. BMC showed the strongest antioxidant activity among the five anti­oxidants in emulsions and its antioxidant activity was almost as strong as BCA in frying. Its soybean oil-water partition coefficient was 9.18 due to its ester and tert-butyl groups, far greater than those of MC (4.82), BCA (2.41), CA (0.84) and TBHQ (3.22). This meant that it was much more soluble in the lipid phase than the other four antioxidants in emulsions. The DPPH radical scavenging activity of BMC was near TBHQ, lower than the other three because of its steric hindrance and less functional phenolic hydroxyl groups compared to others when their masses were the same.

scholarly journals Natural Flavones and Flavonols: Relationships among Antioxidant Activity, Glycation, and Metalloproteinase Inhibition

Cosmetics ◽  
2020 ◽  
Vol 7 (3) ◽  
pp. 71 ◽  
Author(s):  
Simone Ronsisvalle ◽  
Federica Panarello ◽  
Giusy Longhitano ◽  
Edy Angela Siciliano ◽  
Lucia Montenegro ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Advanced Glycation Endproducts ◽  
Hydroxyl Group ◽  
Log P ◽  
Hydroxyl Groups ◽  
Inhibitory Effects ◽  
Chemical Parameters ◽  
Glycation Endproducts ◽  
Body Tissues ◽  
Physico Chemical

Reactive oxygen and nitrogen species as well as advanced glycation endproducts (AGEs) and metalloproteinases (MMPs) play a key role in the development and progression of degenerative processes of body tissues, including skin. Natural antioxidant flavonoids could be beneficial in inhibiting AGEs’ formation and MMPs’ expression. In this study, the antioxidant activity of flavones (luteolin, apigenin, and chrysin) and flavonols (mirycetin, quercetin, and kaempferol) was compared with their inhibitory effects on both metalloproteinases’ (MMP-1, MMP-2, MMP-9, MMP-13) and AGEs’ formation. Comparisons were performed taking into account the hydroxyl group arrangement and the physico-chemical parameters the binding dissociation enthalpy (BDE), ionization potential (IP), partition coefficient (log P), and topological polar surface area (TPSA). Increasing the number of hydroxyl groups led to a proportional enhancement of antioxidant activity while an inverse relationship was observed plotting the antioxidant activity vs. BDE and IP values. All flavonoids acted as AGEs, MMP-1, and MMP-13 inhibitors, but they were less effective against MMP-2 and MMP-9. The inhibition of MMP-1 seemed to be related to the TPSA values while high TPSA and low log P values seemed important conditions for inhibiting MMP-13. Overall, our data suggest that an estimation of flavonoid activity could be anticipated based on their physico-chemical parameters.

scholarly journals Antioxidant activity and mechanism of action of some synthesised phenolic acid amides of aromatic amines

2013 ◽  
Vol 31 (No. 1) ◽  
pp. 5-13 ◽  
Author(s):  
E. Marinova ◽  
L. Georgiev ◽  
I. Totseva ◽  
K. Seizova ◽  
T. Milkova
Keyword(s):  
Antioxidant Activity ◽  
Caffeic Acid ◽  
Mechanism Of Action ◽  
Sunflower Oil ◽  
Aromatic Amines ◽  
Kinetic Data ◽  
Side Reaction ◽  
Hydroxyl Groups ◽  
Direct Oxidation ◽  
Derivatives Of

The antioxidative activities and mechanism of action were studied of eight synthesised cinnamoyl- and hydroxycinnamoyl amides of biogenic amines (caffeoyldopamine, cinnamoyldopamine, p-coumaroyldopamine, feruloyldopamine, sinapoyldopamine, caffeoylphenylethylamine, caffeoyltyramine, and caffeoyltryptamine) in a wide concentration range (2.5&ndash;20 &times; 10<sup>&ndash;4</sup>M) during autoxidation of triacylglycerols of sunflower oil. It was established that all amides exhibited excellent antioxidant activity, higher than or comparable with that of caffeic acid. The best activity was shown by caffeoyldopamine followed by cinnamoyldopamine and caffeoyltyramine. The analysis of the kinetic data obtained showed that the presence of hydroxyl groups in the amino part (derivatives of dopamine and tyramine) led to direct oxidation of the molecules during the process and stabilisation of the resulting radicals. In contrast, the amides without hydroxyl groups in the amino part participated in the side reaction with peroxides and the resulting radicals took part in one side reaction of the chain propagation as did caffeic acid. &nbsp;

scholarly journals Study of Antioxidant Activity of Some Medicinal Plants Having High Content of Caffeic Acid Derivatives

Antioxidants ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 412 ◽  
Author(s):  
Agnieszka Tajner-Czopek ◽  
Mateusz Gertchen ◽  
Elżbieta Rytel ◽  
Agnieszka Kita ◽  
Alicja Z. Kucharska ◽  
...  
Keyword(s):  
Antioxidant Activity ◽  
Medicinal Plants ◽  
Caffeic Acid ◽  
Radical Scavenging Activity ◽  
Radical Scavenging ◽  
Ethanolic Extract ◽  
Scavenging Activity ◽  
Caffeic Acid Derivatives ◽  
Chicoric Acid ◽  
Ethanolic Extracts

Recently, there has been increasing interest in medicinal plants, due to their content of health-promoting compounds, e.g., caffeic acids derivatives. Hence, the aim of this work was to study the antioxidant activity of extracts obtained from the following medicinal plants: caraway (Carum carvi L.), coltsfoot (Tussilago farfara L.), dandelion (Taraxacum officinale F.H.Wigg.), lovage (Levisticum officinale L.), tarragon (Artemisia dracunculus L.) and white mulberry (Morus alba L.), characterized by their high content of caffeic acid derivatives. The water-ethanolic extracts were characterized on average by about 9 times higher contents of caffeic acid derivatives level than water extracts. Both in water and water-ethanolic extracts, the dominant phenolic acid was 5-CQA (5-O-caffeoylquinic acid) and 3,4-diCQA (3,4-dicaffeoylquinic acid), then CCA-1 (chicoric acid isomer 1), which appeared only in water-ethanolic extracts. Extracts from dandelion contained compounds such as CTA (caftaric acid), CCA-1 (chicoric acid isomer 1) and CCA-2 (chicoric acid isomer 2), which were not detected in other plant extracts examined in this work. The water-ethanolic extracts from coltsfoot and tarragon were characterized by a high content of di-caffeoylquinic acids, especially 3,4-diCQA and 3,5-diCQA, respectively. It has been stated that there is a positive correlation between caffeic acid derivatives and antioxidant activity (radical cation scavenging activity (ABTS) and radical scavenging activity (DPPH)), especially in water-ethanolic extract of medicinal plants.

scholarly journals Reactivity of Aliphatic and Phenolic Hydroxyl Groups in Kraft Lignin towards 4,4′ MDI

Molecules ◽  
2021 ◽  
Vol 26 (8) ◽  
pp. 2131
Author(s):  
Leonardo Dalseno Antonino ◽  
Júlia Rocha Gouveia ◽  
Rogério Ramos de Sousa Júnior ◽  
Guilherme Elias Saltarelli Garcia ◽  
Luara Carneiro Gobbo ◽  
...  
Keyword(s):  
Experimental Work ◽  
Chemical Structure ◽  
31P Nmr ◽  
Kraft Lignin ◽  
Hydroxyl Group ◽  
Hydroxyl Groups ◽  
Diphenylmethane Diisocyanate ◽  
Complex Chemical ◽  
Heterogeneous Reactivity ◽  
Phenolic Hydroxyl Groups

Several efforts have been dedicated to the development of lignin-based polyurethanes (PU) in recent years. The low and heterogeneous reactivity of lignin hydroxyl groups towards diisocyanates, arising from their highly complex chemical structure, limits the application of this biopolymer in PU synthesis. Besides the well-known differences in the reactivity of aliphatic and aromatic hydroxyl groups, experimental work in which the reactivity of both types of hydroxyl, especially the aromatic ones present in syringyl (S-unit), guaiacyl (G-unit), and p-hydroxyphenyl (H-unit) building units are considered and compared, is still lacking in the literature. In this work, the hydroxyl reactivity of two kraft lignin grades towards 4,4′-diphenylmethane diisocyanate (MDI) was investigated. 31P NMR allowed the monitoring of the reactivity of each hydroxyl group in the lignin structure. FTIR spectra revealed the evolution of peaks related to hydroxyl consumption and urethane formation. These results might support new PU developments, including the use of unmodified lignin and the synthesis of MDI-functionalized biopolymers or prepolymers.

scholarly journals A One-Pot Approach to Novel Pyridazine C-Nucleosides

Molecules ◽  
2021 ◽  
Vol 26 (8) ◽  
pp. 2341
Author(s):  
Flavio Cermola ◽  
Serena Vella ◽  
Marina DellaGreca ◽  
Angela Tuzi ◽  
Maria Rosaria Iesce
Keyword(s):  
Organic Chemistry ◽  
Research Field ◽  
Modified Nucleosides ◽  
Protecting Groups ◽  
Coupling Reactions ◽  
One Pot ◽  
Pharmacological Interest ◽  
Classical Methodology ◽  
Glycosyl Donor ◽  
Neutral Conditions

The synthesis of glycosides and modified nucleosides represents a wide research field in organic chemistry. The classical methodology is based on coupling reactions between a glycosyl donor and an acceptor. An alternative strategy for new C-nucleosides is used in this approach, which consists of modifying a pre-existent furyl aglycone. This approach is applied to obtain novel pyridazine C-nucleosides starting with 2- and 3-(ribofuranosyl)furans. It is based on singlet oxygen [4+2] cycloaddition followed by reduction and hydrazine cyclization under neutral conditions. The mild three-step one-pot procedure leads stereoselectively to novel pyridazine C-nucleosides of pharmacological interest. The use of acetyls as protecting groups provides an elegant direct route to a deprotected new pyridazine C-nucleoside.

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

Molecules ◽  
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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