Evaluation of the antioxidant and antibacterial properties of ethanol extracts from berries,leaves and stems of Hedera pastuchovii Woron. ex Grossh

This study was designed to examine the total phenolic and flavonoid contents, radical scavenging and antibacterial activity of the ethanolic extracts from leaves, berries and stems of Hedera pastuchovii Woron. ex Grossh. The berry extract, which contained the highest phenolic and flavonoid compounds, showed an appreciable DPPH^√ scavenging ability in comparison with leaf and stem extracts. The various extracts exhibited moderate to good activity against both Gram-negative and Gram-positive bacteria, and the effectiveness of leaf extract was higher for all tested bacteria.     

Antimicrobial,DPPH scavenging and tyrosinase inhibitory activities of Thymus vulgaris,Helichrysum arenarium and Rosa damascena mill. ethanol extracts by using TLC bioautography and chemical screening methods

Antimicrobial, DPPH scavenging and tyrosinase inhibitory activities of Thymus vulgaris, Helichrysum arenarium and Rosa damascena Mill. ethanol extracts by using TLC bioautography and chemical screening methods. The ethanol extracts of Thymus vulgaris (Tv), Helichrysum arenarium (Ha) and Rosa damascena Mill. (Rm) (red) were screened for their antimicrobial, 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical scavenging and tyrosinase inhibitory activities. The test microorganisms included bacteria of Escherichia coli (ATCC 25922) and Staphylococcus aureus (ATCC 25923). Thin Layer Chromatography (TLC) - bioautography, disk diffusion and well diffusion methods were used for the antimicrobial activity assays. Rosa damascena Mill. extract was effective against E. coli and all plant extracts showed antimicrobial activity against S. aureus. The phenolic acids in the structure of the extracts were also identified by LC-MS analysis. Human blood agar well diffusion method and TLC-DPPH assays were used to identify the hemolytic and antioxidant activity of plant extracts, respectively, along with 10 compounds including phenolic acids as a standard. Among these compounds, caffeic acid (Rf = 0.68) was detected in all extracts while vanillic acid (Rf = 0.75), and gallic acid (Rf = 0.51) was found in Tv extract. Kojic acid (Rf = 0.36), on the other hand, was detected in Rm extract as a tyrosinase inhibitor. All plant extracts presented tyrosinase inhibitory activities on TLC-bioautography assay.     

Identification and in vitro antioxidant activities of phenolic compounds isolated from Cynoglossum cheirifolium L.

In an extensive search for bioactive compounds from plant sources, the quantitative and qualitative characterisation of the compounds present in Cynoglossum cheirifolium extracts was studied. Total phenolic and flavonoid contents were determined by spectrophotometric techniques. In vitro antioxidant and radical scavenging profiling was determined through DPPH^? scavenging activity and Ferric reducing antioxidant power (FRAP). Our study showed that leaves produce more phenolic compounds, followed by flowering aerial part. The butanolic fraction obtained from leaves extract exhibited the highest total phenolics (78.65 ± 3.58 mg GAE/g DW) and flavonoids (22.15 ± 4.66 mg CE/g DW). In contrast, this fraction displayed the highest DPPH^? scavenging ability with IC₅₀ values of 0.06 ± 0.003 mg/mL. The RP-HPLC-PDA analysis of phenolic compounds from leaves of C. cheirifolium lets to identify: rosmarinic acid, ferulic acid, caffeic acid, p-coumaric acid, syringic acid, sinapic acid and rutin. The obtained results indicate that this plant represent a valuable source of natural antioxidants.     

An Insight into Kiwiberry Leaf Valorization: Phenolic Composition,Bioactivity and Health Benefits

During kiwiberry production, different by-products are generated, including leaves that are removed to increase the fruit’s solar exposure. The aim of this work was to extract bioactive compounds from kiwiberry leaf by employing microwave-assisted extraction (MAE). Compatible food solvents (water and ethanol) were employed. The alcoholic extract contained the highest phenolic and flavonoid contents (629.48 mg of gallic acid equivalents (GAE) per gram of plant material on dry weight (dw) (GAE/g dw) and 136.81 mg of catechin equivalents per gram of plant material on dw (CAE/g dw), respectively). Oppositely, the hydroalcoholic extract achieved the highest antioxidant activity and scavenging activity against reactive oxygen and nitrogen species (IC₅₀ = 29.10 μg/mL for O₂^•−, IC₅₀ = 1.87 μg/mL for HOCl and IC₅₀ = 1.18 μg/mL for ^•NO). The phenolic profile showed the presence of caffeoylquinic acids, proanthocyanidin, and quercetin in all samples. However, caffeoylquinic acids and quercetin were detected in higher amounts in the alcoholic extract, while proanthocyanidins were prevalent in the hydroalcoholic extract. No adverse effects were observed on Caco-2 viability, while the highest concentration (1000 µg/mL) of hydroalcoholic and alcoholic extracts conducted to a decrease of HT29-MTX viability. These results highlight the MAE potentialities to extract bioactive compounds from kiwiberry leaf.     

Phytochemical composition,in vitro antioxidant activity and antibacterial mechanisms of Neolamarckia cadamba fruits extracts

Aqueous extracts of Neolamarckia cadamba fruits prepared at different maturity stages were used for the analysis of various phytochemicals, and their antioxidant and antibacterial activities were determined. Ripe fruit extract had highest phenolics (3.14 mM GAE/ g fruit extract) with caffeic acid, tannic acid, syringic acid and quercetin as major phenolic compounds. The ripe fruit extract showed lowest IC₅₀ values in DPPH radical scavenging assay (231.33 μg fruit extract/ mL), and highest ABTS radical scavenging activity (111.18 μM TEAC/g). Immature fruit extract showed lowest minimum inhibitory concentration against tested bacteria, and the antibacterial activity was probably due to membrane permeation, as was evident by leakage of genetic material and reduction in propidium iodide uptake by bacterium; and by inhibition of sugar and amino acid uptake. The appreciable amount of phenolic compounds and biological activities in the aqueous extracts of N. cadamba fruits suggests it's potential application as natural preservative.     

HPLC-ESI-MS/MS analysis of phenolics and in vitro antioxidant activity of Epilobium angustifolium L.

The aerial parts of Epilobium plants are widely used as folk medicine and food around the world. The present study was aimed to investigate the antioxidant activities and active chemical constituents from Epilobium angustifolium L. The results revealed that the EtOAc extract, rich in phenolic compounds and flavonoids (16.81 ± 0.67 g GAE/100 g extract and 4.95 ± 0.21 g QE/100 g extract, respectively), possessed significantly antioxidant activities in reducing power, DPPH radical scavenging activity, ABTS radical scavenging activity and highly in inhibiting lipid peroxidation activity. Simultaneously, active fractions F to H from EtOAc extracts showing potent in vitro antioxidant activities also contained high content of total phenolic and flavonoid. Twenty-eight compounds were identified as phenolic compounds and flavonoids by LC-MS/MS. The results illustrate that the E. angustifolium L., which is rich in phenolics, could be used as a natural resource of antioxidant ingredient.     

Analysis of phenolic compounds from different morphological parts of Helichrysum devium by liquid chromatography with on‐line UV and electrospray ionization mass spectrometric detection

A simple and rapid method has been used for the screening and identification of the main phenolic compounds from Helichrysum devium using high‐performance liquid chromatography with on‐line UV and electrospray ionization mass spectrometric detection (LC‐DAD/ESI‐MSⁿ). The total aerial parts and different morphological parts of the plant, namely leaves, flowers and stems, were analyzed separately. A total of 34 compounds present in the methanolic extract from Helichrysum devium were identified or tentatively characterized based on their UV and mass spectra and retention times. Three of these compounds were positively identified by comparison with reference standards. The phenolic compounds included derivatives of quinic acid, O‐glycosylated flavonoids, a caffeic acid derivative and a protocatechuic acid derivative. The characteristic loss of 206 Da from malonylcaffeoyl quinic acid was used to confirm the malonyl linkage to the caffeoyl group. This contribution presents one of the first reports on the analysis of phenolic compounds from Helichrysum devium using LC‐DAD/ESI‐MSⁿ and highlights the prominence of quinic acid derivatives as the main group of phenolic compounds present in these extracts. We also provide evidence that the methanolic extract from the flowers was significantly more complex when compared to that of other morphological parts. Copyright © 2009 John Wiley & Sons, Ltd.     

Phytochemical Profiling and Evaluation of the Hepatoprotective Effect of Cuscuta Campestris by High-Performance Liquid Chromatography with Diode Array Detection

Plant-derived antioxidant compounds have the potential to prevent cell damage caused by free radicals. As a holoparasitic plant, Cuscuta campestris Yuncker is being valorized for treatment of liver injury and cancer prevention in traditional medicine. The main purpose of this present study is to elucidate the antioxidant- and anticancer-associated contents of C. campestris by spectroscopic and chromatographic methods. Diethyl ether, ethyl acetate, methanol, n-butanol, and water were used as extraction solvents to reach a wide range of secondary metabolites synthesized by this plant. Antioxidant potentials of these extracts were characterized by (2,2-diphenyl-1-picrylhydrazyl)-free radical scavenging activity. Their anticancer activities were evaluated on SNU-398 hepatocellular carcinoma cells and controlled on the normal adult human dermal fibroblasts (hDFs) cells. Their phenolic compounds were analyzed by high-performance liquid chromatography with diode array detector to illuminate the responsible anticancer agent(s). The ethyl acetate extract revealed the most significant antioxidant effect. Methanol and ethyl acetate extracts were found to be cytotoxic on the SNU-398 cell lines with CC₅₀ values of 18.7 and 19.6?µg?mL^?1, respectively, whereas these extracts were not cytotoxic to the adult hDFs cells. Due to their abundance in the extracts, isorhamnetin, kaempferol, and quercetin may have caused this anticancer activity. Methanol extract has the highest concentration of phenolic compounds. Based on chromatographic analyses, we propose that these anticancer effects were positively correlated with plant phenolic compounds. The results showed that this plant is worth further study for its therapeutic uses.     

Characterization of the Phytochemical Profiles and Biological Activities of Ajuga chamaepitys subsp. chia var. chia and Ajuga bombycina by High-Performance Liquid Chromatography–Electrospray Ionization–Tandem Mass Spectrometry (HPLC–ESI–MSn)

This study investigates into the pharmacological potential of three solvent extracts (ethyl acetate, methanol, and water) of two Ajuga species (Ajuga chamaepitys subsp. chia var. chia and Ajuga bombycina) based on their antioxidant activity and enzyme inhibitory effects along with establishing the phytochemical profile. Spectrophotometric and high-performance liquid chromatography–electrospray ionization–tandem mass spectrometry (HPLC–ESI–MSⁿ) were used to determine the total and individual phytocompounds, respectively. Antioxidant potential was assessed using different assays such as DPPH, ABTS, CUPRAC, FRAP, phosphomolybdenum, and metal chelation. Enzyme inhibitory effects were studied against acetylcholinesterase, butyrylcholinesterase, tyrosinase, α-amylase, and α-glucosidase. The aqueous extract of both plants showed better ABTS scavenging, FRAP, and metal chelating activities. The methanol extracts displayed the highest tyrosinase inhibitory and antioxidant activity in the phosphomolybdenum assay while the ethyl acetate extracts of both plants showed better butyrylcholinesterase (BChE), α-amylase, and α-glucosidase inhibition. The total phenolic content was highest in the aqueous extract of A. chamaepitys while the methanolic extract of A. bombycina showed the highest flavonoid content. Identification by HPLC–ESI–MSⁿ revealed the presence of some individual compounds including phenolic acids, flavonoids, iridoid glycosides, phenylethanoid glycosides, and other compounds. To conclude, both A. chamaepitys and A. bombycina can be considered as rich sources of phytocompounds to manage chronic diseases.     

Bioactive compounds and antioxidant activity of Rhaponticum acaule (L.) DC

Abstract

Rhaponticum acaule (L.) DC. is a medicinal plant commonly used for the treatment of some illnesses such as gastrointestinal infections. In this work, we report the composition of different parts of this plant on phenolic compounds, their quantification, and antioxidant activity. The obtained results reported that methanolic extracts of the three parts studied revealed high phenolic contents. For flavonoid contents, the highest contents were reported in organic extracts of leaf part. In addition, results obtained from the study of the antioxidant activity showed that methanolic extract of root presented the highest activity, in DPPH^? scavenging ability test with an IC₅₀ of 0.31?±?0.04?mg/mL and in FRAP test with an EC₅₀ of 1.06?±?0.02?mg/mL. The RP-HPLC-PDA analysis revealed the presence of five phenolic acids (sinapic, caffeic, chlorogenic, ferulic and syringic acids), one flavanone (naringenin), one flavonol (rutin) and vanillin.     

Antioxidant and antifungal activity of different extracts obtained from aerial parts of Inula crithmoides L.

The total phenolic content, antioxidant and antifungal activities of three Inula crithmoides extracts (n-hexane, methylene chloride and MeOH) were investigated. The methanolic extract showed the highest total phenolic content. In the DPPH assay, the methanolic and hexane extracts exhibited the highest DPPH-radical scavenging activity; in the 5-lipoxygenase assay, the hexane extract showed greater inhibitory effect with an IC₅₀ similar to that of Trolox and ascorbic acid. The antifungal activity of the methanolic extract revealed a higher activity against Phytophtora cryptogea and Alternaria solani.     

HPLC profiling of phenolics and flavonoids of Adonidia merrillii fruits and their antioxidant and cytotoxic properties

In this study the antioxidant and cytotoxicity activity of the Adonidia merrillii fruits were investigated using different solvent polarities (methanol, ethyl acetate and water). The results showed that the total phenolic and flavonoid contents of the methanolic extract was higher compare with other extract with respective values of 17.80 ± 0.45 mg gallic acid equivalents/g dry weight (DW) and 5.43 ± 0.33 mg rutin equivalents/g DW. Beside that The RP-HPLC analyses indicated the presence of gallic acid, pyrogallol, caffeic acid, vanillic acid, syringic acid, naringin and rutin. In the DPPH, NO2 and ABTS scavenging assays, the methanolic extract exhibited higher antioxidant activity as compared to the ethyl acetate and water extracts. The extracts exhibited moderate to weak cytotoxic activity in the assays using human hepatocytes (Chang liver cells) and NIH/3T3 (fibroblasts cell) cell lines. The findings showed the Adonidia merrillii fruit extracts to possess considerable antioxidant and cytotoxicity properties. The fruit, therefore, is a potential candidate for further work to discover antioxidant and cytotoxic drugs from natural sources.     

Phenol-Derived Carbon Sealant Inspired by a Coalification Process

Recently, emerging functions utilizing phenolic molecules, such as surface functionalizing agents or bioadhesives, have attracted significant interest. However, the most important role of phenolic compounds is to produce carbonized plant matter called “coal”, which is widely used as an energy source in nearly all countries. Coalification is a long-term, high-temperature process in which phenols are converted into conducting carbonized matter. This study focuses on mimicking coalification processes to create conducting sealants from non-conducting phenolic compounds by heat treatment. We demonstrate that a phenolic adhesive, tri-hydroxybenzene (known as pyrogallol), and polyethylenimine mixture initially acts as an adhesive sealant that can be converted to a conducting carbon sealing material. The conductivity of the phenolic sealant is about 850 Ω⁻¹ cm⁻¹, which is an approximately two-fold enhancement of the performance of carbon matter. Applications of the biomimetic adhesives described herein include conducting defect sealants in carbon nanomaterials and conducting binders for metal/carbon or ceramic/carbon composites.     

Lagoecia cuminoides L., its antioxidant activity and polyphenolic constituents from Iran

Lagoecia cuminoides L. belongs to the family of Umbelliferae (Apiaceae), and known also as common wild cumin. The aerial parts of L. cuminoides were collected at the flowering stage and dried, then the methanolic extract was analyzed for polyphenol compounds identified by HPLC-DAD and antioxidant activity (DPPH(2,2-diphenyl-1-picrylhydrazyl) radical scavenging assay). It was found that the predominant phenolic constituents were chlorogenic acid, hesperidin, rosmarinic acid, hesperetin and vanillin. The antioxidant activity of methanolic extract from L. cuminoides was found 1597 μg/mL in DPPH scavenging assay. There is no strict positive relationship between the polyphenolic content and antioxidant activity of extracts.     

Insecticidal Activity and Free Radical Scavenging Properties of Isolated Phytoconstituents from the Saudi Plant Nuxia oppositifolia (Hochst.)

Chromatographic purification of the alcoholic extract from the aerial parts of the Saudi plant Nuxia oppositifolia (Hochst.), Benth., resulted in five isolated phenolic compounds. Two flavones, hispidulin (1) and jaceosidin (2), and the phenylethanoid glycosides, verbascoside (3), isoverbascoside (4), and conandroside (5), were identified and their chemical structures were determined by spectroscopic analyses. The insecticidal activity of compounds 1 and 2, in addition to 11 compounds isolated in a previous research (6–16), was evaluated against the Yellow Fever mosquito, Aedes aegypti. Four compounds displayed adulticidal activity with LD₅₀ values of 2–2.3 μg/mosquito. Free radical scavenging properties of the plant extracts and compounds (1–5) were evaluated by measuring the 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) and 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonate radical cation (ABTS^•+) scavenging activity. All compounds exhibited notable activity, compared with the positive control, l-Ascorbic acid. This study suggests that N. oppositifolia could be a promising source of secondary metabolites, some with lethal adulticidal effect against Ae. aegypti.     

Determination of phenolic compounds,in vitro antioxidant activity and characterization of secondary metabolites in different parts of Passiflora cincinnata by HPLC-DAD-MS/MS analysis

Abstract

Ethanol extracts of different parts of Passiflora cincinnata were obtained by maceration. The total phenolic and flavonoid contents were evaluated. The antioxidant activities were determined by β-carotene-linoleic acid bleaching test, 2,2-diphenyl-1-picrylhydrazil (DPPH), and 2,2’-azinobis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) radical scavenging. The crude ethanol stem extract showed the highest amount of total polyphenols (45.53?mg gallic acid equivalent/g) while the highest total flavonoid contents (1.42?mg of quercetin equivalent/g) were observed in the leaf extract. The lowest IC₅₀ (25.65?μg/ml) by the DPPH method was observed for the stem extract. The ABTS method showed a significant antioxidant activity for all investigated extracts. The secondary metabolite composition of ethanol extracts was assessed by HPLC-DAD-MS/MS analysis, leading to the identification of fourteen secondary metabolites in P. cincinnata extracts. These results showed the potentiality of this species as a source of phenolic compounds and antioxidants.     

Screening of antioxidant activity and volatile compounds composition of Chamerion angustifolium (L.) Holub ecotypes grown in Lithuania

Since biological activity of medicinal plants is dependent on cultivation area, climatic conditions, developmental stage, genetic modifications and other factors, it is important to study flora present in different growing sites and geographical zones. This study was focused on screening of antioxidant activity of C. angustifolium harvested in six different locations in Lithuania. The total contents of phenolic compounds, flavonoids and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity were evaluated by spectrophotometric methods. A correlation between radical scavenging activity and total phenolic compounds content was observed (correlation coefficient 0.98). HPLC with online post-column DPPH radical scavenging reaction detection was used for the separation of extracts. Oenothein B, rutin and one unidentified compound were predominant. Volatile compounds were analysed using solid-phase microextraction coupled with gas chromatography–mass spectrometry. Based on the analysis of volatiles, all samples were classified into two chemotypes: (I) with predominant α- and β-caryophyllenes and (II) with predominant anethole.     

Anti-Escherichia coli activity of extracts from Schinus terebinthifolius fruits and leaves

Ethanol extracts obtained from Schinus terebinthifolius Raddi fruits and leaves were active against Escherichia coli with MIC of 78 μg mL^?1 for both extracts. Phytochemical analyses revealed a major presence of phenolic acids, tannins, fatty acids and acid triterpenes in the leaves and phenolic acids, fatty acids, acid triterpenes and biflavonoids in the fruits. Major compounds isolated from the plant, such as the acid triterpene schinol, the phenolic acid derivative ethyl gallate and the biflavonoids agathisflavone and tetrahydroamentoflavone, showed very little activity against E. coli. Bioautography of the ethanol extracts on silica gel plate showed inhibition zones for E. coli. They were removed from the plate and the compounds identified as a mixture of myristic, pentadecanoic, palmitic, heptadecanoic, stearic, nonadecanoic, eicosanoic, heneicosanoic and behenic fatty acids.     

Evaluation of the antioxidant and antibacterial properties of various solvents extracts of Annona squamosa L. leaves

The present work was conducted aiming to evaluate the effect of different solvent extracts on the antioxidant and antibacterial activities of Annona squamosa L. leaves. Four solvents were chosen for the study namely; methanol 80%, acetone 50%, ethanol 50% and boiling water. Acetone and boiling water gave the highest extraction yields as compared to methanol and ethanol. Total phenolic contents of the four extracts were significantly different with acetone being the most efficient solvent and water being the least efficient one. Correlation coefficient between the total antioxidant and total phenolic content was found to be R² = 0.89 suggesting the contribution of phenolic compounds of the extract by 89% to its total antioxidant activity. The extracts were capable of scavenging H₂O₂ in a range of 43–54%. Reducing power of the extracts increased by increasing their concentration. The extracts were found to exert low to moderate antibacterial activity compared to a standard antibacterial agent. The bacterial inhibition of the extracts was found to positively correlate with their phenolic contents.     

Determination of the Free Radical Scavenging Activity of Lycium Extracts

Lycium species growing in Turkey have not so far been studied sufficiently. For this reason, non-polar and polar extracts obtained from the fruits of Lycium barbarum L. and L. Ruthenicum Murray (Solanaceae) were assessed both in vitro for their potential as free radical scavenger crude extracts and their phenolic composition. Fruits of Lycium species were sequentially extracted with petroleum ether, ethyl acetate, methanol, n-butanol, and water in a Soxhlet extractor. All the extracts were assessed for the scavenging of the nitrogen-centered free radical 1,1-diphenyl-2-picrylhydrazyl (DPPH^.) by in vitro method. Furthermore, the composition of each extract was investigated both in terms of its Folin-Ciocalteau reactive components and its qualitative content. The phenolic compounds within the extracts were determined as benzoic acid and hydroxycinnamic acid derivatives, flavonoids, and anthocyanins according to their retention time and UV spectral data by HPLC-DAD system.