Phenolic Compounds In Ethanol Extracts Research Articles

Antioxidant Activity of Phenolic Compounds in Ethanolic Extract of Hibiscus sabdariffa L. on Oxidative Stability of Soybean Oil

Background:The current interest in natural antioxidants from vegetable sources, mainly in bioactive antioxidants, has been increasing in Brazil. The Hibiscus sabdariffa L. is rich in bioactive compounds, besides having antioxidant and antimicrobial properties.Objective:This study aimed to evaluate the antioxidant effect of hibiscus extract on the oxidative stability of soybean oil in an accelerated storage test.Methods:The ethanolic extracts of calyces and hibiscus seeds were evaluated for total phenolic compounds and antioxidant activity using DPPH, FRAP, and β-carotene/linoleic acid. The treatments identified as OS, Tocopherol, Extract, and Mixture, were prepared and submitted to accelerated storage at 60°C. The samples were analyzed on days 0, 6, and 12 for peroxides index, p-anisidine, total oxidation value, oxidative stability, and tocopherols.Results:The extract of calyces of hibiscus presented higher amounts of total phenolic compounds and antioxidant activity. Therefore, it was added to soybean oil. The Extract treatment promoted greater efficiency to inhibit the formation of primary and secondary compounds of lipid oxidation. It provided high oxidative stability to the soybean oil, in addition to greater retention of tocopherols, mainly α- and γ-tocopherol isomers.Conclusion:Among the treatments studied, Extract promoted greater efficiency in the inhibition of the formation of primary and secondary compounds of lipid oxidation, besides providing greater oxidative stability and greater retention of tocopherols during storage.

METHOD FOR DETERMINING THE TOTAL CONTENT OF PHENOLIC COMPOUNDS IN PLANT EXTRACTS WITH FOLIN-DENIS REAGENT AND FOLIN-CHOCALTEU REAGENT: MODIFICATION AND COMPARISON

A modification of the method for determining the total content of phenolic compounds in plant tissue extracts with the Folin-Denis reagent and the Folin-Ciocalteu reagent has been carried out, allowing to establish the correspondence of the results obtained when using them. The method using the Folin-Denis reagent is adapted for conducting determinations in microvolumes. For the method using the Folin-Ciocalteu reagent, the concentration of the latter (0.4 N, a 5-fold dilution of the standard reagent) and the composition of the reaction mixture were selected, using which the optical densities of the reduction products of the Folin-Denis and Folin-Ciocalteu reagents containing polyphenols in ethanol extracts from wheat, buckwheat and calus tissue of tea were almost the same. The absorption spectra of the reduction products of these reagents by gallic acid, rutin, (-)-epicatechin, as well as ethanol extracts from wheat, buckwheat, and tea calus tissue, were located in the same region (680–770 nm) and had similar characteristics. Calibration graphs of the dependence of the optical density of solutions on the concentration of standard substances (gallic acid, (-)-epicatechin, rutin), constructed using the Folin-Denis and Folin-Ciocalteu reagents, had a linear character within the concentration range of 10–100 μg/ml and practically coincided. The results of determining the content of phenolic compounds in ethanol extracts of plants, differing in their ability to accumulate, showed very similar and statistically significant values when using these two reagents.

Comparative Study on Polyphenols Content and Antioxid ant Activity of Three Sweet Peppers Varieties (Capsicum annuum L.)

Background:The genus Capsicum contains various sweet and hot pepper varieties, including Capsicum annum L. The various species in this genus are used as herbs, vegetables, or medicines, and recent studies have shown that they are a rich source of bioactive compounds as well.Objective:In this study, our objective was to evaluate the antioxidant activity as well as the content of phenols (TPC), the content of flavonoids (TFC) and total condensed tannins (TCT) of ethanolic extracts of the fresh and dried sweet pepper Capsicum annuum L.Methods:The antioxidant activities of the extracts were examined using different biochemical assays, namely diphenylpicrylhydrazyl (DPPH), total antioxidant capacity (TAC) and ferric reducing power (FRAP). The total phenolic contents (TPC) were determined spectrophotometrically according to the Folin-Ciocalteu colorimetric method. Total flavonoid content was measured by the aluminum chloride colorimetric assay. High-performance liquid chromatography (HPLC) has been used to identify the phenolic compounds in ethanolic extracts.Results:The obtained results showed the presence of considerable amounts of total phenolic (757.3±3.5 mgGAE/100g), flavonoid (482.66±1.5 mgQE/100g) and Condensed Tannins (15.97±0.5 mg GAE/100g) content in dry red pepper extract. The use of HPLC has allowed the identification of Gallic Acid, Ascorbic Acid, Chlorogenic Acid, Caffeic Acid, Quercetin, Vanillin, and Rutin in pepper ethanolic extracts. Green and yellow dry peppers contain significant amounts of gallic acid exceeding (134.0 μg /mg). The fresh yellow and red peppers also contained significant amounts of Quercetin exceeding (109.3 μg/mg), the dry red pepper has the strongest antioxidant activity.Conclusion:In conclusion, these findings can be regarded as very promising and justify further study, including the identification of antioxidant components in pepper extracts. Our work constitutes a first step in the study of fresh and dry sweet pepper as a promising source of natural antioxidants.

Stock Plant Material of St John’s Wort (Hypericum perforatum L.) Based on Biotechnology

Biotechnology applied in the production of medicinal plant biomass will facilitate the multiplication and use of high-quality renewable medicinal materials without destroying natural resources. The study was aimed at the progeny plants of Hypericum perforatum L., Zolotodolinsky cultivar, morphological and anatomical evaluation to identify differences between conventional plant material and the one obtained through biotechnological methods, its biochemical analysis. The technique was developed for clonal micropropagation of Hypericum perforatum L., Zolotodolinsky cultivar. The paper presents a microscopic analysis of St. John’s wort material grown in tissue culture. The key microscopic signs that have diagnostic value are the structure and size of the epidermis, veins, and also 3 types of floral cups. Macro- and microdiagnostic signs were found to be identical in the intact and progeny plants. A phytochemical analysis suggested the presence of phenolic compounds in ethanol extracts (70%) from H. perforatum progeny plants. The content of extractives was established to make up 12.8±0.6%, a total of flavonoids – 5±1%, the amount of tannins – 6.40±0.01% per ADM of progeny plants. For the first time, Hypericum perforatum L. was established to have the content of xanthones 0.20±0.01% per ADM in terms of mangiferin.

Variability in the Qualitative and Quantitative Composition and Content of Phenolic Compounds in the Fruit of Introduced American Cranberry (Vaccinium macrocarpon Aiton).

The aim of this study was to determine the composition and content of phenolic compounds in ethanol extracts of eight different cultivars of American cranberry (Vaccinium macrocarpon Aiton) fruit using spectrophotometric and UPLC-ESI-MS/MS analysis and to evaluate the antioxidant activity in vitro of these extracts. The highest total amount of phenolic compounds evaluated via Folin–Ciocalteu spectrophotometry was detected in American cranberry fruit samples of the ‘Bain’ clone, and the highest total amount of flavonoids was found in samples of the ‘Drever’ and ‘Baiwfay’ cultivars. The highest total amount of the individual phenolic compounds (519.53 ± 25.12 mg/g DW) identified and quantitatively evaluated via chromatography was detected in samples of the ‘Searles’ cranberry cultivar. In the studied cranberry samples, the predominant phenolic compounds were hyperoside, quercetin, and procyanidin A2, while the amounts of other compounds were significantly lower. HCA and PCA revealed that ‘Woolman’, ‘Holliston’, ‘Pilgrim, and ‘Searles’ fruit samples had different quantitative content of phenolic compounds from other cranberry cultivars. Meanwhile, fruit of ‘Baiwfay’, ‘Drever’, ‘Bain’, and ‘Bergman’ were similar in their phytochemical profile.

Phytoconstituent Analysis and Antibacterial Potential of Epicarp Extracts from Mature Fruits of Persea americana Mill

Background: World Health Organization (WHO) has reported the antimicrobial resistance as one among the ten threats to global health in 2019. The development of plant-derived antibiotics is currently considered as a modern medicine’s greatest success. Persea americana is a plant with high medicinal profile which allow its different parts to be used for therapeutic purposes. This study is aimed to determine the antibacterial potential of ethanol and chloroform extracts from epicarp of mature fruits of P. americana Mill against human pathogens.Materials and Methods: The epicarps of avocado were dried in oven and ground into powder using porcelain mortar and pestle. The powdered plant materials were extracted with both 96% ethanol and chloroform. Extracts were qualitatively screened to examine their bioactive contents and agar well diffusion method was used to analyze the antibacterial activity of extracts against both Gram-positive and Gram-negative bacteria.Results: Both solvents showed the ability to dissolve the secondary metabolites from avocado epicarps. Phytochemical screening disclosed the presence of alkaloids, proteins, terpenoids, tannins, flavonoids, steroids and phenolic compounds in ethanolic extracts and absence of flavonoids and tannins in chloroform extracts. The extracts showed the inhibition zones ranging from 14±4.5 mm to 26±2.1 mm while streptomycin demonstrated high inhibition zones ranging from 20±3.1 mm to 30 mm. The minimum inhibitory concentration (MIC) values of extracts fall in the range of 0.3125 mg/mL and 20 mg/mL while the MIC values for streptomycin vary from 0.25 mg/mL to 1.25 mg/mL.Conclusion: The ethanol and chloroform extracts proved to be potentially effective and to be used as natural alternative preventives to fight against various disease-causing bacteria.Keywords: antibacterial activity, ethanol extract, chloroform extract, Persea americana, Rwanda

Didžiųjų dilgėlių ekstraktų antioksidacinio aktyvumo ir fenolinių junginių eksperimentiniai tyrimai

Organizmo patiriamas oksidacinis stresas siejamas su sunkiomis sveikatos problemomis – širdies ir kraujagyslių ligomis, autoimuninės nervų sistemos sutrikdymu, imuninės sistemos slopinimu. Viena iš priemonių, vartojamų oksidaciniam stresui mažinti, yra augaliniai preparatai. Didžiųjų dilgėlių (Urtica dioica L.) vaistinė augalinė žaliava – lapai Urticae folium (Ph.Eur.01/2008:1897) įtraukti į Europos farmakopėją. Pasaulyje atliekami didžiųjų dilgėlių kaupiamų biologiškai aktyvių junginių gydomojo poveikio bei antioksidacinio aktyvumo tyrimai. Kokybinės ir kiekinės cheminės sudėties duomenys sudaro sąlygas ruošti norminius dokumentus atitinkančią žaliavą, todėl biologiškai aktyvių junginių kokybinės ir kiekybinės įvairovės augalų organuose tyrimai yra perspektyvūs. Tyrimo tikslas: nustatyti didžiosios dilgėlės lapuose sukauptų fenolinių junginių kiekinės sudėties bei antioksidacinio aktyvumo kitimą vegetacijos periodo metu. Tyrimo objektas - didžiosios dilgėlės lapai, surinkti 2015 m. gegužės – rugpjūčio mėn. Kauno raj. Fenolinių junginių kiekiai etanoliniuose didžiųjų dilgėlių ekstraktuose nustatyti Folin-Ciocalteu metodu. Antioksidacinis aktyvumas nustatytas laisvųjų radikalų (DPPH∙) surišimo aktyvumo nustatymo metodu. Ištyrus natūralioje augavietėje augančių didžiųjų dilgėlių lapuose esančių fenolinių junginių kiekinės sudėties kitimą nustatyta, kad didžiausias fenolinių junginių kiekis yra dilgėlių lapuose, surinktuose iki žydėjimo. Pastebėta, kad stipriausiu antioksidaciniu aktyvumu pasižymi iki žydėjimo rinktų dilgėlių lapų ekstraktai.

Variation of quantitative composition of phenolic compounds in rowan (Sorbus aucuparia L.) leaves during the growth season

The aim of our study was to explore variation peculiarities of qualitative and quantitative composition of phenolic compounds in leaf samples of rowan (Sorbus aucuparia L.) plants growing in natural habitats of Lithuania during their growth season using the HPLC method. In rowan leaf samples, collected during different phenological stages, qualitative and quantitative estimation of neochlorogenic acid, chlorogenic acid, caffeic acid, hyperoside, isoquercitrin, rutin, astragalin, ( − )-epicatechin, procyanidin B1 and procyanidin B2 was performed. Analysis of the qualitative and quantitative composition of phenolic compounds in ethanol extracts of leaf samples of S. aucuparia growing in natural habitats of Lithuania revealed a close relationship between the content of phenolic compounds in S. aucuparia raw plant material and different growth stages.

In vitro and in vivo antioxidant activity of ethanolic extract of white button mushroom (Agaricus bisporus)

The antioxidant activities of ethanolic extract from edible mushroom Agaricus bisporus (A. bisporus) were evaluated by various methods in vitro and in vivo. In antioxidant assays in vitro, ethanolic extract of A. bisporus was found to have strong reducing power, superoxide radical, hydroxyl radical and 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity, and moderate hydrogen peroxide scavenging activity. In antioxidant assays in vivo, mice were administered with ethanolic extract of A. bisporus via gavage for 30 consecutive days. As a result, administration of ethanolic extract significantly enhanced the activities of antioxidant enzymes in serums, livers and hearts of mice. In addition, the total phenolic content in the extract determined by Folin–Ciocalteu method was 6.18mg of gallic acid equivalents per gram of dry weight. The main phenolic compounds in ethanolic extract analyzed by ultra-high performance liquid chromatography tandem mass spectrometry were determined as gallic acid, protocatechuic acid, catechin, caffeic acid, ferulic acid and myricetin. These results suggested that ethanolic extract of A. bisporus had potent antioxidant activity and could be explored as a novel natural antioxidant.

Characterization of phenolic compounds and antioxidant activity of ethanolic extracts from flowers of Andryala glandulosa ssp. varia (Lowe ex DC.) R.Fern., an endemic species of Macaronesia region

Andryala glandulosa spp. varia (Lowe ex DC.) R.Fern. (Asteraceae), is a small shrub that grows in mountains of Madeira Island, Fuerteventura and Lanzarote from Canary Islands. The flowerheads are used traditionally for the treatment of edemas and in homemade dermo-cosmetic preparations.In this paper the chemical composition of the extracts of this plant, used in folk medicine, and their antioxidant capacity were established; the presence of potentially harmful lactones, so commonly associated with related species used for the same purposes was also evaluated. A reversed-phase high-performance liquid chromatography method (RP-HPLC) coupled with diode-array detection (DAD) and electrospray ionization mass spectrometry (ESI/MSn) was used for the characterization of phenolic compounds in ethanol extracts of flowers from A. glandulosa spp. varia collected in Madeira Island. Total phenolic content (TPC) and total flavonoid content (TFC) were established and three assays (DPPH, ABTS and FRAP) were used to measure the antioxidant capacity of the dichloromethane and ethanol extracts.The dichloromethane extract of A. glandulosa contain long linear chain hydrocarbons and esters. In the alcoholic extracts, a total of 16 compounds were characterized based on their UV, mass spectra and HPLC retention time. Quinic acid and luteolin derivatives were found to be the main compounds. Quantification of caffeoylquinic acids (CQA) detected was performed by HPLC-DAD and 5-O-CQA and 3,5-O-diCQA were the major compounds (with values of 22.40±0.21 and 59.69±1.07mg/100g dried plant, respectively). Only the ethanol extract was active, revealing a high radical scavenging capacity and a moderate reducing potential.The potent antioxidant alcoholic extracts are composed mainly of hydroxycinnamic acid derivatives and flavonoids. The presence of sesquiterpene lactones was not detected. Since lactones are very common among related plants, like arnicas, and known to cause dermatitis and other unwanted effects, this can be an explanation for the preference for Andryala over other more easily available alternatives.

Antioxidant potential and content of phenolic compounds in ethanolic extracts of selected parts of Andrographis paniculata

The present study investigated the antioxidant capacity and total content of phenolic compounds in an ethanolic extract of leaves, stems and fruits ofAndrographis paniculata, a medicinal plant. The antioxidant activity of the samples was evaluated by the red cell hemolysis assay, free radical scavenging and superoxide dismutase activities. The Folin–Ciocalteu reagent assay was used to estimate the phenolic content of extracts. Leaf extracts showed the highest antioxidant potential followed by stem and fruit extracts with the rabbit erythrocytes hemolysis and superoxide dismutase activity assays. However, A.paniculata fruit extracts exhibited the highest DPPH free radical scavenging activity compared to the other extracts. A positive correlation between free radical scavenging capacity and the content of phenolic compounds was found in the fruit, leaf and stem extracts of this plant. Key words: Andrographis paniculata, erythrocytes hemolysis, superoxide dismutase, radical scavenging, phenolic content.

RP‐HPTLC densitometric determination and validation of vanillin and related phenolic compounds in accelerated solvent extract of Vanilla planifolia*

A simple, fast and sensitive RP-HPTLC method is developed for simultaneous quantitative determination of vanillin and related phenolic compounds in ethanolic extracts of Vanilla planifolia pods. In addition to this, the applicability of accelerated solvent extraction (ASE) as an alternative to microwave-assisted extraction (MAE), ultrasound-assisted extraction (UAE) and Soxhlet extraction was also explored for the rapid extraction of phenolic compounds in vanilla pods. Good separation was achieved on aluminium plates precoated with silica gel RP-18 F(254S) in the mobile phase of methanol/water/isopropanol/acetic acid (30:65:2:3, by volume). The method showed good linearity, high precision and good recovery of compounds of interest. ASE showed good extraction efficiency in less time as compared to other techniques for all the phenolic compounds. The present method would be useful for analytical research and for routine analysis of vanilla extracts for their quality control.

Development and validation of an RP‐HPLC method for quantitative determination of vanillin and related phenolic compounds in Vanilla planifolia

A simple and fast method was developed using RP-HPLC for separation and quantitative determination of vanillin and related phenolic compounds in ethanolic extract of pods of Vanilla planifolia. Ten phenolic compounds, namely 4-hydroxybenzyl alcohol, vanillyl alcohol, 3,4-dihydroxybenzaldehyde, 4-hydroxybenzoic acid, vanillic acid, 4-hydroxybenzaldehyde, vanillin, p-coumaric acid, ferulic acid, and piperonal were quantitatively determined using ACN, methanol, and 0.2% acetic acid in water as a mobile phase with a gradient elution mode. The method showed good linearity, high precision, and good recovery of compounds of interest. The present method would be useful for analytical research and for routine analysis of vanilla extracts for their quality control.

Improved determination of vanillin and related phenolic components in vanilla (Vanilla fragrans (Salisb.) Ames) by high‐performance liquid chromatography

AbstractThis paper describes a reverse‐phase high‐performance liquid chromatographic (HPLC) method for the separation, identification and quantification of vanillin and related phenolic compounds in ethanolic extracts of cured vanilla. The compounds were separated on a silica column, bonded with pentafluorophenyl, using a mobile phase gradient of methanol–citric acid with diode‐array detection at 275 nm. Vanillin, vanillic acid, p‐hydroxybenzoic acid and p‐hydroxybenzaldehyde were identified by the spectral data and retention times given by reference compounds. Retention times and spectral data for a further 36 compounds are presented. The new HPLC technique allows a more accurate means of determining the vanillin content of vanilla than the ISO spectrophotometric assay.