How Does the Phenol Structure Influence the Results of the Folin-Ciocalteu Assay?

Plants produce a diverse array of secondary metabolites that are generally nonessential but facilitate ecological interactions. Fruits, vegetables, seeds and nuts can accumulate bioactive secondary metabolites with health-promoting properties, including the potent antioxidant activities of phenolic compounds. Several in vitro assays have been developed to measure the polyphenol content and antioxidant activity of plant extracts, e.g., the simple and highly popular Folin-Ciocalteu (FC) assay. However, the literature contains a number of different descriptions of the assay and it is unclear whether the assay measures the polyphenol content or reducing capacity of the sample. To determine the influence of phenolic structures on the outcome of the FC assay, we tested phenols representing different subgroups (phenolic acids, flavonols, flavanols, dihydrochalcones and flavanones). We observed different results for each reference substance and subgroup. Accordingly, we concluded that the FC assay does not measure the polyphenol content of a sample but determines its reducing capacity instead. Assigning the substances to five structural classes showed that the FC results depend on the number of fulfilled Bors criteria. If a molecule fulfills none of the Bors criteria, the FC results depend on the number of OH groups. We did not find a correlation with other single electron transfer assays (e.g., ABTS and DPPH assays). Furthermore, the FC assay was compatible with all five subgroups and should be preferred over the DPPH assay, which is specific for extracts rich in dihydrochalcones or flavanones.

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Behaviour of 9-Ethyl-9H-carbazole Hydrazone Derivatives Against Oxidant Systems

Croatica Chemica Acta ◽

10.5562/cca3481 ◽

2019 ◽

Vol 92 (1) ◽

pp. 87-94 ◽

Cited By ~ 2

Author(s):

Cigdem Karaaslan ◽

Hande Gurer-Orhan ◽

Sibel Suzen ◽

Luciano Saso ◽

Omidreza Firuzi ◽

...

Keyword(s):

Antioxidant Activities ◽

Radical Scavenging Activity ◽

Radical Scavenging ◽

Amyloid Β ◽

In Vitro Assays ◽

Cytotoxic Activities ◽

Scavenging Activity ◽

Neuroprotective Effects ◽

Neuronal Pc12 Cells

Antioxidants are helpful in prevention of several diseases related with oxidative stress including neurodegenerative disorders. In recent studies, carbazoles were given proof of promising antioxidant activities. In this article, 9-ethyl-9H-carbazole hydrazone derivatives were synthesized, characterized and their in vitro antioxidant activity and possible cytotoxic effects were investigated. Furthermore, protective effect of the synthesized derivatives against amyloid β-induced damage in PC12 neuronal cells was examined by using MTT assay. The newly synthesized carbazoles were found to have radical scavenging activity with a varying potency both in cell-free and cell-based in vitro assays. Several compounds, especially such as 3d and 3e, 3m and 3n bearing two halogen groups on the phenyl ring, were found to have cytotoxic activity. However, their cytotoxic activities were not higher than that of melatonin. Several compounds also significantly protected neuronal PC12 cells against amyloid β-induced damage, which can be defined as neuroprotective agents. (4-(2-((9-Ethyl-9H-carbazol-3-yl)methylene)hydrazinyl)benzonitrile) 3r was found as the most active compound with both radical scavenging activity and neuroprotective effects against amyloid β-induced damage. These findings might provide an alternative strategy for developing novel carbazole derivatives for management of neurodegenerative diseases, such as Alzheimer's disease.

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CYTOTOXIC AND ANTIOXIDANT ACTIVITIES OF SECONDARY METABOLITES FROM PULICARIA UNDULATA

International Journal of Pharmacy and Pharmaceutical Sciences ◽

10.22159/ijpps.2016v8i9.12814 ◽

2016 ◽

Vol 8 (9) ◽

pp. 150 ◽

Cited By ~ 6

Author(s):

Taha A. Hussien ◽

Sayed A. El-toumy ◽

Hossam M. Hassan ◽

Mona H. Hetta

Keyword(s):

Antioxidant Activity ◽

Secondary Metabolites ◽

Antioxidant Activities ◽

Structure Activity Relationship ◽

Activity Relationship ◽

Hep G2 ◽

Structure Activity ◽

Dpph Method ◽

Mcf 7

Objective: To evaluate the in vitro cytotoxicity, antioxidant activities and structure-activity relationship of secondary metabolites isolated from Pulicaria undulata.Methods: The methylene chloride-methanol (1:1) extract of the air-dried aerial parts of Pulicaria undulata was fractionated and separated to obtain the isolated compounds by different chromatographic techniques. Structures of the isolated compounds were determined on the basis of the extensive spectroscopic analysis, including 1D and 2D NMR and compared with the literature data. The crude extract and the isolated compounds were evaluated for in vitro antioxidant activity using the 2,2 diphenyl dipicryl hydrazine (DPPH) method and cytotoxic assay using human breast cancer (MCF-7) and hepatoma (Hep G2) cell line.Results: Nine secondary metabolites were isolated from Pulicaria undulata in this study. Of which two terpenoidal compounds; 8-epi-ivalbin and 11β, 13-dihydro-4H-xanthalongin 4-O-β-D-glucopyranoside firstly isolated from the genus pulicaria and three flavonoids; eupatolitin, 6-methoxykaempferol, and patulitrin firstly isolated from P. undulata. 6-methoxykaempferol (IC50 2.3 µg/ml) showed the most potent antioxidant activity. The highest cytotoxic effect against MCF-7 and Hep G2 cells was obtained with eupatolitin (IC50 27.6 and 23.5 µg/ml) respectively. The structure-activity relationship was also examined and the findings presented here showed that 3, 5, 7, 4' and 3, 5, 4', 5'-hydroxy flavonoids were potent antioxidant and has cytotoxic activity.Conclusion: Pulicaria undulata is a promising medicinal plant, and our study tends to support the therapeutic value of this plant as antioxidant drug and in the treatment of cancer.

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Identification of phenolic secondary metabolites from Schotia brachypetala Sond. (Fabaceae) and demonstration of their antioxidant activities in Caenorhabditis elegans

10.7287/peerj.preprints.1768v1 ◽

2016 ◽

Author(s):

Mansour Sobeh ◽

Esraa A ElHawary ◽

Herbenya Peixoto ◽

Rola M Labib ◽

Heba Handoussa ◽

...

Keyword(s):

Antioxidant Activity ◽

Caenorhabditis Elegans ◽

Nuclear Translocation ◽

Antioxidant Activities ◽

In Vitro Assays ◽

Flavonoid Glycosides ◽

Alcoholic Extract ◽

C Elegans

Background: Schotia brachypetala Sond. (Fabaceae) is an endemic tree of Southern Africa whose phytochemistry and pharmacology were slightly studied.The present work aimed at profiling the major phenolics compounds present in the hydro-alcoholic extract from S. brachypetala leaves (SBE) using LC/HRESI/MS/MS and NMR and prove their antioxidant capabilities using novel methods. Methods: In vitro assays; DPPH, TEAC persulfate decolorizing kinetic and FRAP assays, and in vivo assays: Caenorhabditis elegans strains maintenance, Intracellular ROS in C. elegans, Survival assay, GFP expression and Subcellular DAF-16 localization were employed to evaluate the antioxidant activity. Results: More than forty polyphenols ,including flavonoid glycosides, galloylated flavonoid glycosides, isoflavones, dihydrochalcones, procyanidins, anthocyanins, hydroxybenzoic acid derivatives, hydrolysable tannins, and traces of methylated and acetylated flavonoid derivatives were identified. Three compounds were isolated and identified from the genus Schotia for the first time, namely gallic acid, myricetin-3-O-α-L-1C4-rhamnoside and quercetin-3-O-L-1C4-rhamnoside.The tested extract was able to protect the worms against juglone induced oxidative stress and attenuate the reactive oxygen species (ROS) accumulation. SBE was also able to attenuate the levels of heat shock protein (HSP) expression. Discussion: A pronounced antioxidant activity in vivo, which can be attributed to its ability to promote the nuclear translocation of DAF-16/FOXO, the main transcription factor regulating the expression of stress response genes. The remarkable antioxidant activity in vitro and in vivo correlates to SBE rich phenolic profile.

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Multi-omics reveals the positive leverage of plant secondary metabolites on the gut microbiota in a non-model mammal

Microbiome ◽

10.1186/s40168-021-01142-6 ◽

2021 ◽

Vol 9 (1) ◽

Author(s):

Le Wang ◽

Guangping Huang ◽

Rong Hou ◽

Dunwu Qi ◽

Qi Wu ◽

...

Keyword(s):

Secondary Metabolites ◽

Gut Microbiota ◽

Giant Panda ◽

Plant Secondary Metabolites ◽

Interactive Effects ◽

Bamboo Leaves ◽

Ideal System ◽

Health Promoting ◽

Insight Into

Abstract Background Flavonoids are important plant secondary metabolites (PSMs) that have been widely used for their health-promoting effects. However, little is known about overall flavonoid metabolism and the interactive effects between flavonoids and the gut microbiota. The flavonoid-rich bamboo and the giant panda provide an ideal system to bridge this gap. Results Here, integrating metabolomic and metagenomic approaches, and in vitro culture experiment, we identified 97 flavonoids in bamboo and most of them have not been identified previously; the utilization of more than 70% flavonoid monomers was attributed to gut microbiota; the variation of flavonoid in bamboo leaves and shoots shaped the seasonal microbial fluctuation. The greater the flavonoid content in the diet was, the lower microbial diversity and virulence factor, but the more cellulose-degrading species. Conclusions Our study shows an unprecedented landscape of beneficial PSMs in a non-model mammal and reveals that PSMs remodel the gut microbiota conferring host adaptation to diet transition in an ecological context, providing a novel insight into host-microbe interaction.

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Antioxidant Activities of the Leaf Extract and Fractions of Dryopteris filix-mas (L.) Schott could be Attributed to The Abundance of Polyphenol Compounds

Biology Medicine & Natural Product Chemistry ◽

10.14421/biomedich.2020.91.1-6 ◽

2020 ◽

Vol 9 (1) ◽

pp. 1-6

Author(s):

Earnest Oghenesuvwe Erhirhie ◽

Emmanuel Emeka Ilodigwe ◽

Daniel Lotanna Ajaghaku ◽

Blessing Ogechukwu Umeokoli ◽

Peter Maduabuchi Eze ◽

...

Keyword(s):

Ethyl Acetate ◽

Leaf Extract ◽

Antioxidant Activities ◽

Radical Scavenging Activity ◽

Radical Scavenging ◽

Bioactive Compound ◽

Ethyl Acetate Fraction ◽

In Vitro Assays ◽

Anti Oxidant

Dryopteris filix mas (D filix-mas) is wildly used in ethnomedicine for the management of rheumatoid arthritis, wounds and other diseases. We investigated the anti-oxidant activities of its leaf extract, and chromatographic fractions. The ethanol leaf extract was partitioned into four fractions; n-hexane, ethyl acetate, n-butanol and water. Ferric reducing anti-oxidant power (FRAP), 1, 1-diphenyl-2-picrylhydrazil (DPPH) and nitric oxide (NO) scavenging in vitro assays were carried out on the extract and fractions at 6.25, 12.5, 25, 50, 100, 200, 400 and 800 µg/mL. The most active fraction (ethyl acetate fraction) was further purified using chromatographic techniques to isolate its major compound whose structure was elucidated using ID nuclear magnetic resonance (NMR) and mass spectrometry. The ethyl acetate fraction produced the highest free radical scavenging activity among the other fractions. The fraction (VLC-E7) from which the bioactive compound, quercetin-3-O-αL-rhamnopyranoside, was isolated had the best FRAP and DPPH scavenging activities with EC50 and IC50 values of 88.81 ± 3.41 and 26.87 ± 0.24 respectively more than the ethyl acetate fraction. This study revealed that the polyphenol flavonoid, quercetin-3-O-αL-rhamnopyranoside could be responsible for antioxidant activity of ethno-medicinal property of D filix-mas leaf.

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Pomegranate Byproduct Extracts as Ingredients for Producing Experimental Cheese with Enhanced Microbiological, Functional, and Physical Characteristics

Foods ◽

10.3390/foods10112669 ◽

2021 ◽

Vol 10 (11) ◽

pp. 2669

Author(s):

Lucia Parafati ◽

Fabiola Pesce ◽

Laura Siracusa ◽

Biagio Fallico ◽

Cristina Restuccia ◽

...

Keyword(s):

Antimicrobial Activity ◽

Food Poisoning ◽

Raw Milk ◽

In Vitro Assays ◽

Polyphenol Content ◽

Pomegranate Peel ◽

Food Preservatives ◽

Physico Chemical ◽

Antimicrobial And Antioxidant Activity

Pomegranate peel and mesocarp, considered as wastes of fruit processing, are rich sources of beneficial phytochemicals, including hydrolyzable tannins and flavonoids, with proven antimicrobial and antioxidant activity, which can be employed for improving the overall quality of food products. In the present study, extracts from pomegranate peel (PPW) and mesocarp (PMW) were obtained through a water extraction method and evaluated for in vitro antimicrobial activity and polyphenol content. The two extracts were then added during the cheese-making process in order to create a new functional cheese with improved microbiological and physico-chemical characteristics. Antimicrobial in vitro assays evidenced a substantial efficacy of both extracts against Staphylococcus aureus, which often causes staphylococcal food poisoning outbreaks linked to the consumption of raw milk cheeses and artisanal cheeses. For this reason, a simulated cheese contamination was carried out in order to assess if pomegranate extracts can exert antimicrobial activity towards this pathogen even when incorporated into the cheese matrix. Milk enriched with pomegranate extracts (PPW and PMW) was used to produce two different experimental cheeses, which were then evaluated for yield, polyphenol content, and microbiological as well as physico-chemical traits throughout the refrigerated storage. Despite the low concentration of the extracts, the treated cheeses showed an increase in firmness and a slight decrease in S. aureus counts, of more than one log unit in comparison to the control cheese, for up to 12 d of cold storage. Such results support the reuse of agro-food byproducts, in substitution to chemical food preservatives, as the key to a circular economy.

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Screening of Selected Sri Lankan Seasonal Fruit Extracts for Total Antioxidant Activity in vitro

Asian Journal of Pharmaceutical Research and Development ◽

10.22270/ajprd.v7i1.459 ◽

2019 ◽

Vol 7 (1) ◽

pp. 7-12

Author(s):

Amarosige Shanoli Kavindya Fernando ◽

Anoja Priyadarshani Attanayake ◽

Kamani Ayoma Perera Wijewardena Jayatilaka

Keyword(s):

Antioxidant Activity ◽

Antioxidant Activities ◽

Dry Weight ◽

Total Antioxidant Activity ◽

Polyphenol Content ◽

Total Polyphenol ◽

Fruit Extracts ◽

Total Polyphenol Content ◽

Total Antioxidant

The present study aimed to determine the total polyphenol content and total antioxidant activities of ten selected seasonal fruit extracts grown in Sri Lanka. The aqueous refluxed fruit extracts (4h) were used at the initial concentration of 0.05 g/mL. The total polyphenol content was determined according to the Folin-Ciocalteu method. The total antioxidant activity was evaluated by DPPH (2, 2-diphenyl-2-picrylhydrazyl), FRAP (ferric reducing power) and TBA (thiobabituric acid assay) assays with L-ascorbic acid as the reference compound. The total polyphenol content of the fruit extracts varied from 0.81±0 to 17.54±0.50 mg GAE (gallic acid equivalents) per gram of dry weight. The antioxidant activities ranged in IC50 of 46.60±0.60 to 367.90 ± 4.90 μg/mL, 3.41±0.02 to 50.46±1.02 µM, 30.62±0.50 to 182.64±0.90 mg AAE (L-ascorbic acid equivalents) per gram of dry weight for DPPH, FRAP, TBA assays, respectively. All aqueous fruit extracts exert dose dependent in vitro antioxidant activities in different degrees. Among the selected fruit extracts S. carophylatum, P. zeylanica, A. comosus exert relatively high total antioxidant activity together with high total polyphenol content. Hence, the selected fruit extracts are deserved to be as potent sources for antioxidant lead compounds in the development of nutraceuticals using the above edible fruits.

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Polyphenolic Profile and Varied Bioactivities of Processed Taiwanese Grown Broccoli: A Comparative Study of Edible and Non-Edible Parts

Pharmaceuticals ◽

10.3390/ph13050082 ◽

2020 ◽

Vol 13 (5) ◽

pp. 82 ◽

Cited By ~ 1

Author(s):

Thanh Ninh Le ◽

Napat Sakulsataporn ◽

Chiu-Hsia Chiu ◽

Pao-Chuan Hsieh

Keyword(s):

High Performance ◽

Inhibitory Concentration ◽

Antioxidant Activities ◽

Antibacterial Properties ◽

Pharmaceutical Products ◽

Health Promoting ◽

Weak Activity ◽

Promising Source ◽

Edible Parts

Broccoli contains a substantial amount of bioactive compounds such as glucosinolates, phenolics, and essential nutrients, which are positively linked to health-promoting effects. This work aimed to evaluate whether both edible and non-edible parts of broccoli could be effective by examining in vitro antioxidant, cytotoxic, apoptotic, and antibacterial properties of its floret, leaf, and seed extracts (FE, LE, and SE, correspondingly). High-performance liquid chromatography (HPLC) and various assays exhibited strong antioxidant activities of all samples. LE obtained the highest capacity, correlated to its polyphenolic contents. SE exerted significant cytotoxicity against A549, Caco-2, and HepG2 cancer cell lines at low inhibitory concentration (IC)50 values (0.134, 0.209, and 0.238 mg/mL, respectively), as tested by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Flow cytometry confirmed apoptosis induction of extracts in Caco-2 cells by revealing an increased subG1 population and a decreased mitochondrial membrane potential. The considerable antibacterial efficacy was observed in either LE and SE against Bacillus subtilis and Salmonella typhimurium (0.39–0.78 mg/mL) using well-agar diffusion and minimum inhibitory concentration (MIC) techniques, along with the weak activity against Staphylococcus aureus and Escherichia coli (1.56–3.13 mg/mL). The findings suggest that broccoli and its byproducts might serve as a promising source for further development of food or pharmaceutical products.

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Characterization of Composition and Antifungal Properties of Leaf Secondary Metabolites from Thirteen Cultivars of Chrysanthemum morifolium Ramat

Molecules ◽

10.3390/molecules24234202 ◽

2019 ◽

Vol 24 (23) ◽

pp. 4202 ◽

Cited By ~ 2

Author(s):

Huanhuan Xue ◽

Yifan Jiang ◽

Hongwei Zhao ◽

Tobias G. Köllner ◽

Sumei Chen ◽

...

Keyword(s):

Secondary Metabolites ◽

Antifungal Agents ◽

Pathogenic Fungi ◽

Chrysanthemum Morifolium ◽

In Vitro Assays ◽

Gas Chromatography Mass Spectrometry ◽

Leaf Extracts ◽

Antifungal Properties ◽

Chrysanthemum Morifolium Ramat

Chrysanthemum morifolium Ramat is an ornamental plant of worldwide cultivation. Like many other species in the family Asteraceae, C. morifolium is a rich producer of secondary metabolites. There are two objectives in this study: (I) to determine and compare the diversity of apolar secondary metabolites among different cultivars of C. morifolium and (II) to compare their properties as antifungal agents. To attain these objectives, we selected 13 cultivars of C. morifolium that are commonly used for making chrysanthemum tea as experimental materials. Leaves at the same developmental stage were collected from respective mature plants and subjected to organic extraction. The extracts were analyzed using gas chromatography–mass spectrometry. A total of 37 apolar secondary metabolites including 26 terpenoids were detected from the 13 cultivars. These 13 cultivars can be largely divided into three chemotypes based on chemical principal components analysis. Next, the extracts from the 13 cultivars were examined in in vitro assays for their antifungal properties against three species of pathogenic fungi: Fusarium oxysporum, Magnaporthe oryzae, and Verticillium dahliae. Significant variability in antifungal activity of the leaf extracts among different cultivars was observed. The 13 cultivars can be divided into four groups based on their antifungal activities, which could be partly correlated to the contents of terpenoids. In short, this study reveals large variations in chemical composition, particularly of terpenoids, of leaf secondary metabolites among different cultivars of C. morifolium and their different abilities in functioning as antifungal agents.

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Phytochemical and Biological Activities of five Turanecio Hamzaoglu (Asteraceae) Species from Turkey

Current Enzyme Inhibition ◽

10.2174/1573408012666160808095059 ◽

2017 ◽

Vol 13 (1) ◽

pp. 49-55

Author(s):

Sevil Albayrak ◽

Ahmet Aksoy ◽

Abit Yasar ◽

Lutfiye Yurtseven ◽

Umit Budak

Keyword(s):

Therapeutic Potential ◽

Antioxidant Activities ◽

Biological Activities ◽

Natural Antioxidants ◽

Antibacterial Activities ◽

Antimicrobial Activities ◽

In Vitro Assays ◽

Methanolic Extracts ◽

Promising Source

Objectives: In vitro biological activities of methanolic extracts of five Turanecio species have been studied. Materials and Methods: The phenolic compositions of the extracts were evaluated by the Folin- Ciocalteu assay and by HPLC analysis. Antioxidant activities were determined with two in vitro assays namely, DPPH (2,2-diphenyl-1-picrylhydrazyl) scavenging assay and phosphomolybdenum assay. The antimicrobial activities of the extracts were evaluated against 13 microorganisms. Results: T. hypochionaeus var. hypochionaeus was showed the highest DPPH inhibition with 88.84% at 100 μg·mL-1. All of the extracts were exerted high total antioxidant activities 128.00- 243.13 mg AAE g-1) and seem to be a promising source of natural antioxidants. The phenolic contents in the extracts varied from 26.17 to 60.99 mg·g-1 as gallic acid equivalent. Chlorogenic acid, caffeic acid and p- coumaric acid were the predominant constituents. The methanolic extracts revealed promising antibacterial activities against most bacteria. No activity was recorded against yeasts tested. Conclusion: The polyphenolic constituents appear to be responsible, at least in part, for the extract’s activities. The present study confirms that tested Turanecio species contains significant source of phenolics have antioxidant and antimicrobial activities and may have therapeutic potential.

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