Highly chemoselective reduction of aromatic nitro compounds to the corresponding hydroxylamines catalysed by plant cells from a grape (Vitis vinifera L.)

Cells from a grape (Vitis vinifera L.) reduce aromatic nitro compounds under mild conditions to the corresponding hydroxylamines with unprecedented chemoselectivity.     

Annurca peel extract: from the chemical composition,through the functional activity,to the formulation and characterisation of a topical oil-in-water emulsion

The aim of this study was to produce a hydro-alcoholic safe antioxidant Malus pumila Miller cv Annurca peel extract (APE) useful as functional ingredient in an oil-in-water emulsion. Results showed that APE contains a hydroxycinnamic acid (chlorogenic acid), flavonol glycosides (quercetin derivatives) and a dihydrochalcone, phloridzin (phloretin-2-O-glucoside). The isoquercitrin (quercetin-3-O-glucoside) content was quantified in 0.3% w/w of extract. APE showed a significant and concentration-dependent free-radical scavenging activity correlated to its polyphenols content. No cytotoxic effect was observed in primary human epidermal keratinocyte adults and dermal fibroblast cell lines. The formulative approach led to produce a stable emulsion able to load a high amount of APE, up to 6.0% w/w. The homogenous distribution of APE in the emulsion was clearly demonstrated by fluorescence microscopy analysis. The emulsion resulted able to enhance the in vitro release rate of APE through synthetic membranes with respect to the raw material.     

In vitro and in silico interaction of faba bean (Vicia faba L.) seed extract with xanthine oxidase and evaluation of antioxidant activity as a therapeutic potential

Acetone extract of faba bean (Vicia faba L.) was found to be highest total phenol and flavonoid content among all extracts. Antioxidant activity for inhibition percentage (free radical scavenging activity) had 86.47% for acetone extract, and 97.36% for ascorbic acid respectively. IC₅₀ value of ascorbic acid and acetone extact were found to be 9 μg/mL ± 0.20 and 30 μg/mL ± 0.21. Faba bean seeds had catechin, epicatechin, gallic acid and ellagic acid which on molecular docking study revealed that it binds effectively with xanthine oxidase by binding energy of –7.78, –6.11, –6.39, –5.78 kcal/mol respectively compared to allopurinol drug having binding energy of –4.94 kcal/mol. Gallic acid, ellagic acid, catechin, epicatechin (polyphenols) and allopurinol bind other than catalytic residues (Glu-1261) of xanthine oxidase. In vitro and in silico analysis recommended that mode of enzyme inhibition was mixed type.     

Polyphenol contents and antioxidant activity of Brassica nigra (L.) Koch. leaf extract

Profound research has been done on the medicinal value of Brassica nigra (BN) seeds, and the leaves of the plant have been investigated in this study. The methanol extracts of the leaves were subjected to several in?vitro studies. The antioxidant activity of methanol extract was demonstrated with a wide range of concentration, 10-500?μg?mL(-1), and the antioxidant activity increased with the increase in concentration. Total phenol content was found to be 171.73?±?5.043 gallic acid equivalents and the total flavonoid content 7.45?±?0.0945 quercetin equivalents. Further quantification and identification of the compounds were done by HPTLC and GC-MS analyses. The predominant phenolic compounds determined by HPTLC were gallic acid, followed by quercetin, ferulic acid, caffeic acid and rutin. The free radical quenching property of BN leaf extract suggests the presence of bioactive natural compounds.     

Volatile components of vine leaves from two Portuguese grape varieties (Vitis vinifera L.), Touriga Nacional and Tinta Roriz,analysed by solid-phase microextraction

The purpose of this work was to study the volatile composition of vine leaves and vine leaf infusion prepared from vine leaves collected at 30 and 60 days after grape harvest of two Vitis vinifera L. species. Eighteen volatile compounds were identified by gas chromatography–mass spectrometry in vine leaves and in vine leaf infusions. It was observed that the volatile compounds present in vine leaves are dependent on the time of harvest, with benzaldehyde being the major volatile present in vine leaves collected at 30 days after harvesting. There are significant differences in the volatile composition of the leaves from the two grape cultivars, especially in the sample collected at 60 days after grape harvest. This is not reflected in the volatile composition of the vine leaf infusion made from this two cultivars, the more important being the harvesting date for the volatile profile of vine leaf infusion than the vine leaves grape cultivar.     

Variation in minerals, phenolics and antioxidant activity of peel and pulp of different varieties of peach (Prunus persica L.) fruit from Pakistan

Peach (Prunus persica L.), being a potential source of bioactive compounds, has been demonstrated to have medicinal benefits. In this study variation of minerals and antioxidant characteristics (total phenolic contents, total flavonoid contents, reducing power, inhibition of peroxidation using linoleic acid system and DPPH free radical scavenging activity) between peel and pulp parts of different peach varieties, namely Golden, Shireen, and Shahpasand were investigated. The peel and pulp extracts, derived from the varieties analyzed, exhibited an appreciable amount of total phenolics (TP) and total flavonoids (TF), ranging from 1,209.3-1,354.5, 711.7-881.3 mg GAE/100 g and 599.7-785.5, 301.3-499.7 mg CE/100 g on a dry weight basis, respectively. Reducing power of peel and pulp extracts (12.5 mg/mL concentration) ranged from 2.57-2.77 and 1.54-1.99.The inhibition of linoleic acid peroxidation and DPPH scavenging activity of the extracts varied from 70.8-80.9% and 66.8-76.5% in peels, and 51.9-60.1% and 43.4-49.1% in pulps. The mineral analysis revealed that the content of K was highest in both parts of the peach fruit followed by Mg, Ca, Fe, Mn and Zn. The results of our present study indicate that peach peel had significantly higher levels of minerals, antioxidant capacity and phenolics than those of the pulp, suggesting the intake of unpeeled peach as a potential source of high-value components. The peach peel can be a useful as a viable source of natural antioxidants for functional foods and nutraceutical applications.     

Isolation,structural elucidation and in vitro antioxidant activity of compounds from chloroform extract of Cedrus deodara (Roxb.) Loud.

This study was designed to isolate, characterise and explore in vitro antioxidant potential of compounds from the chloroform extract of Cedrus deodara wood belonging to Pinacae family. We have investigated the in vitro free radical scavenging activity of isolated compounds by measuring total antioxidant capacity (TAC) and reducing power ability. From the chloroform extract five sesquiterpenes namely atlantone, himaphenolone, atlantolone, deodardione and atlantone-2,3-diol were identified. Himaphenolone and deodardione from the chloroform extract of this plant have been isolated for the first time. A marked dose-dependent reducing power and strong TAC were found in favour of himaphenolone and atlantone-2,3-diol, respectively. Moreover, deodardione and atlantolone also exhibit good antioxidant potentials. However, atlantone has showed least antioxidant activity. In conclusion, the chloroform extract of C. deodara exhibited significant antioxidant potential mainly due to the presence of sesquiterpenes which may be responsible for various pharmacological activities of this plant.     

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.     

In vitro antimicrobial activity of Pistacia lentiscus L. edible oil and phenolic extract

Pistacia lentiscus L. is known in some Tunisian forest area by its fixed oil used in traditional medicine as an antiseptic product. This investigation is the first to study the antimicrobial activity of P.lentiscus edible oil and its phenolic extract. Oil was extracted from fruits harvested from six provenances located in Tunisia. The antimicrobial activity was tested using disc diffusion assay and the broth dilution method. Kbouch and Sidi Zid oils were most efficient (p < 0.003) against, respectively, Staphylococcus aureus and Aspergillus niger with an inhibition zone of 9.33 mm. The phenolic extract had the largest spectrum of sensitive microorganisms. The minimum inhibitory concentration and minimum bactericidal concentration results showed that all strains were inhibited by both oil and extract.     

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.     

Chemical constituents,in vitro antioxidant and antimicrobial properties of ethyl acetate extract obtained from Cytisus triflorus l’Her

Abstract

The present study investigates the phenolic composition, antioxidant and antimicrobial activities of an ethyl acetate extract from C. triflorus L’Her. The phytochemical study on the aerial parts of C. triflorus belonging to the Fabaceae family led to the isolation and structural elucidation of 5-Hydroxy-7-O-glucosylflavone (P1), 5-Hydroxy-7-O-galactosylflavone (P2), 5,7-Dihydroxy-flavone (P3), 5,7,3’-Trihydroxy,4’-methoxy-flavone (P4). These compounds were identified by 1D and 2D NMR combined analysis as well as by UV.

Ethyl acetate extract of C. triflorus showed a significant and dose-dependent antioxidant activity in vitro, related to the presence of phenolics (180.33?±?12.22?µg GAE/mg) and flavonoids (16.78?± 1.54?µg QE/mg). The antimicrobial activity was evaluated in vitro against Staphylococcus aureus CECT 240 and Escherichia coli CECT 4099, by agar-diffusion method. The most active antibacterial activity was expressed by ethyl acetate extract of C. triflorus against Gram-positive bacteria S. aureus. The gathered results suggest that C. triflorus polyphenols and flavonoids are closely associated to its antioxidant and antimicrobial properties.     

The phytochemical analysis and antioxidant activity assessment of orange peel (Citrus sinensis) cultivated in Greece-Crete indicates a new commercial source of hesperidin

The flavonoid content of several methanolic extract fractions of Navel orange peel (flavedo and albedo of Citrus sinensis) cultivated in Crete (Greece) was first analysed phytochemically and then assessed for its antioxidant activity in vitro. The chemical structures of the constituents fractionated were originally determined by comparing their retention times and the obtained UV spectral data with the available bibliographic data and further verified by detailed LC-DAD-MS (ESI+) analysis. The main flavonoid groups found within the fractions examined were polymethoxylated flavones, O-glycosylated flavones, C-glycosylated flavones, O-glycosylated flavonols, O-glycosylated flavanones and phenolic acids along with their ester derivatives. In addition, the quantitative HPLC analysis confirmed that hesperidin is the major flavonoid glycoside found in the orange peel. Interestingly enough, its quantity at 48 mg/g of dry peel permits the commercial use of orange peel as a source for the production of hesperidin. The antioxidant activity of the orange peel methanolic extract fractions was evaluated by applying two complementary methodologies, DPPH(*) assay and the Co(II)/EDTA-induced luminol chemiluminescence approach. Overall, the results have shown that orange peel methanolic extracts possess moderate antioxidant activity as compared with the activity seen in tests where the corresponding aglycones, diosmetin and hesperetin were assessed in different ratios.     

In vitro wound healing evaluation,antioxidant and chemical profiling of Baeckea frutescens leaves ethanolic extract

Occurrence of the wound or chronic wound, which results to disability, amputation and diminish quality of life, are leading to increased healthcare expenditure around the globe. Despite effective conventional wound healing medicines, the exploration of alternative medicines are continuing process as researchers seek for the approach to reduce the cost of wound healing management. In present study, wound healing properties of ethanolic extract of Baeckea frutescens leaves were determined by evaluating their cytotoxicity, proliferation and migration rate on two types of cells, keratinocytes (HaCaT) and fibroblasts (BJ). Furthermore, the antioxidant properties of this plant were determined by DPPH scavenging, ferric reducing antioxidant power (FRAP) and total phenolics content (TPC) assays. The phytochemistry of the extract was evaluated by phytochemicals screening and liquid chromatography mass spectrometry (LCMS) analysis. Results of this study indicated Baeckea frutescens extract increased the rate of proliferation and migration on both HaCat and BJ cells within their nontoxic doses. The extract also possessed a very good antioxidant property as demonstrated with high DPPH radical scavenging, FRAP and TPC values, comparable to that of Green tea extract, a widely known antioxidant. The phytochemistry analyses and LCMS exhibited the presence saponins, flavonoids, tannins and steroids in Baeckea frutescens extract possibly responsible to their antioxidant and wound healing properties.     

Green synthesis of silver chloride nanoparticles using Prunus persica L. outer peel extract and investigation of antibacterial,anticandidal, antioxidant potential

The present study was conducted to synthesize silver chloride nanoparticles using the aqueous extract of outer peel of peach fruit (Prunus persica L.) and to evaluate its antibacterial activity, synergistic antibacterial and anticandidal potential against five foodborne pathogenic bacteria and five pathogenic Candida species respectively along with its antioxidant potential. The synthesized silver chloride nanoparticles (PE-AgClNPs) were visually confirmed with surface plasmon resonance peak at 440?nm upon UV–Vis spectroscopy analysis. Furthermore, the morphology, elemental composition and crystallinity nature were also characterized. PE-AgClNPs displayed strong antibacterial potentials (9.01–10.83?mm inhibition zone) against foodborne pathogenic bacteria and increased synergistic effect with kanamycin and rifampicin. PE-AgClNPs also displayed strong anticandidal synergistic activity with standard amphotericin b (10.51–14.01?mm inhibition zones), along with strong free radical scavenging and reducing power. Based on strong antibacterial and antioxidant capacities, PE-AgClNPs are anticipated to have potential applications in the biomedical and food sector industries.     

Chemical compositions and antibacterial activity of extracts obtained from the inflorescences of Cirsium canum (L.) all

The aim of this study was to investigate phenolic acids and flavonoids in methanolic, dichloromethane, acetone and ethyl acetate extracts and fractions from inflorescences of Cirsium canum (L.). RP-HPLC analysis enabled identification of the following: chlorogenic acid, caffeic acid, p-coumaric acid, protocatechuic acid, p-hydroxybenzoic acid, vanillic acid, syringic acid, trans-cinnamic acid, luteolin-7-glucoside, apigenin-7-glucoside, kaempferol-3-glucoside, linarin, apigenin, rutoside, luteolin and kaempferol. The antimicrobial activity of tested extracts was determined in vitro against reference microorganisms, including bacteria or fungi, belonging to yeasts. Our data showed that the tested extracts had no influence on the growth of the reference strains of Gram-negative bacteria and yeasts belonging to Candida spp. Among them, the fractions possessed the highest activity against Gram-positive bacteria, especially Streptococcus aureus and Streptococcus pneumoniae belonging to pathogens and Streptococcus epidermidis, Bacillus cereus and Bacillus subtilis belonging to opportunistic microorganisms.     

α-glucosidase inhibitory,antioxidant activity,and GC/MS analysis of Descurainia sophia methanolic extract: In vitro,in vivo,and in silico studies

Due to the presence of various phenolic compounds in D.sophia, this plant may have an inhibitory effect on α-Glc and ultimately diabetes control. Therefore, this work aims to scrutinize total phenolic, flavonoid contents, antioxidant capacity, and α-Glc inhibitory activity in aerial parts of methanolic D.sophia extract. The methanolic flower extracts were selected from among aerial parts for the experimental study of anti-diabetic effects by α-Glc inhibitory assays. The flower extracts were also studied by GC/MS to detect the compounds. The total phenolic and flavonoid contents were 21.38 ± 0.93 GAE/g and 96.2 ± 0.20 QE/g, respectively. The IC₅₀ value of flower extract for α-Glc inhibition with mixed (Competitive/non-competitive) mode was found to be 20.34 ± 0.11 mg/ml. Furthermore, in-vivo studies showed that the blood glucose level reduced after consumption of flower extract compared to the control group. Twenty-one compounds were identified by GC/MS technique. These compounds were assessed for high docking scores against α-Glc in silico. Docking score calculations exhibited that the DES-α-Glc complex had a significantly higher binding energy (-6.13 Kcal/mol) than other compounds. The DES-α-Glc complex which displayed a higher docking energy value than the ACR was subjected to MDs studies. The findings of this study suggest that the flower extract of D.sophia can be used as a suitable additive in syrups or foods with anti-diabetic capacity.     

UHPLC-MS/MS phenolic profiling and in vitro antioxidant activities of Inula graveolens (L.) Desf

Inula graveolens (L.) Desf. is an annual aromatic herb which has various uses on alternative medicine in many region of the world. In this study, antioxidant activities of ethanol and water extracts of the plant leaves were determined by in vitro DPPH method and phenolic composition of the plant sample was determined by LC-MS/MS analysis. The results showed that chlorogenic acid, quinic acid, hyperoside, protocatechuic acid and quercetin were the major phenolic compounds among the 27 standard compounds. The significant antioxidant capacity of the plant might be related with the high abundance of phenolic compounds.     

Extraction technology,component analysis,and in vitro antioxidant and antibacterial activities of total flavonoids and fatty acids from Tribulus terrestris L. fruits

The current study focused on the extraction technology, components analysis, in vitro antioxidant and antibacterial activities of total flavonoids and fatty acids from Tribulus terrestris L. fruits. The extraction process of total flavonoids and fatty acids was optimized by the response surface method, and the compositions were identified from the two extracts by HPLC–DAD–ESI–MS^? and GC–MS, respectively. In addition, the antioxidant and antibacterial activities were evaluated by assay of ABTS, DPPH radical scavenging activity, ferric reducing antioxidant power and minimal inhibitory concentration. The yields of total flavonoids and fatty acids were 0.46 and 9.76% under the optimized conditions. Moreover, nine and eight compositions were identified from the two extracts based on the related references, respectively. In addition, total flavonoids and fatty acids extracts both exhibited certain antioxidant and antibacterial activities. The present findings suggest that total flavonoids extracted from T. terrestris L. fruits comprised a more interesting candidate than fatty acids for the research and development of natural and healthy antioxidants and antibacterial agents for the pharmaceutical and food industries.     

Identification and determination of flavonoids,carotenoids and chlorophyll concentration in Cynodon dactylon (L.) by HPLC analysis

Cynodon dactylon (L.) is a potent medicinal plant in the traditional and current Indian medicinal systems. The objective of this research was to find out the levels of flavonoids, carotenoids and chlorophyll b in C. dactylon leaves by high-performance liquid chromatography (HPLC) equipped with a diode array detector. HPLC analysis revealed that total carotenoid and total flavonoid concentration were 62 mg/100 g and 249.1 μg/g, respectively. The mean chlorophyll b was 85.1 mg/100 g in C. dactylon. Among the flavonoids, quercetin (164.7 μg/g) was the major flavonoid followed by kaempferol (48.2 μg/g), rutin (18.4 μg/g), catechin (12.1 μg/g) and myricetin (5.7 μg/g). Of the carotenoids, β-carotene (35.2 mg/100 g) was predominant followed by lutein (17.0 mg/100 g), violaxanthin (5.8 mg/100 g) and zeaxanthin (4.2 mg/100 g). Chlorophyll b concentration was 85.1 mg/100 g in C. dactylon. The results of this investigation should be useful information for further pharmacological studies.