Search Results

You are looking at 81 - 90 of 243 items for :

Clear All
Open access

Ibtissem Boulacel, Brahim Harkati, Radia Ayad, Ibrahim Demirtas, Hocine Laouer and Salah Akkal

Abstract

The focus of this paper was to assess the phytochemical composition, the antioxidant and antibacterial activities of the crude extracts of the aerial parts of Ferula lutea. Four new compounds were isolated from this genus, and their structures were primarily established by extensive spectroscopic analysis including 1D and 2D spectroscopic techniques. Total phenolics and flavonoids containing in ethyl acetate (AcOEt) and n-butanol (n-BuOH) extracts were quantified [199.1-184.02 mg gallic acid equivalent / g of dry weight], flavonoids [70.24-65.95 mg quercetin / g dry weight]. DDPH scavenging and phosphomolybdenum methods were used to evaluate in vitro antioxidant activity. The obtained results showed a significant antioxidant activity of the two aerial parts. Correlation analysis between the DPPH values and those for TAC indicates the possibility of the two models for evaluating antioxidants power from medicinal plants. Dichloromethane (CH2Cl2), AcOEt and n-BuOH extracts were screened against two gram-negative [Escherichia coli (E.coli) and Pseudo aeruginosa (P.aer)] and two gram-positive [Staphylococcus aureus (S.aur) and Bacillus (Bacil.)] bacteria using disc diffusion method. The results indicate a good inhibition of CH2Cl2 and EtAct extracts on the growth of (Bacil. and E.coli). Furthermore n-but extract showed a significant inhibitory effect only against E.coli.

Open access

Muttalip Gundogdu, Ihsan Canan, Mustafa K. Gecer, Tuncay Kan and Sezai Ercisli

Abstract

The study was carried out in 2014 and 2015, and aimed to determine some important biochemical and antioxidant characteristics of the fruits of mulberry (Morus spp.) cultivars and genotypes found in Malatya (Turkey). Phenolic compounds (protocatechuic acid, vanillic acid, ellagic acid, rutin, quercetin, gallic acid, catechin, chlorogenic acid, caffeic acid, syringic acid, p-coumaric acid, o-coumaric acid, phloridzin and ferulic acid), organic acids, sugars, vitamin C and antioxidant capacity were analyzed in sampled fruits. The results showed that most of the biochemical content and antioxidant capacities of the cultivars and genotypes were significantly different from one another (p < 0.05). Among the phenolic compounds, rutin (118.23 mg 100 g-1), gallic acid (36.85 mg 100 g-1), and chlorogenic acid (92.07 mg 100 g-1) were determined to have the highest values for most of the fruit samples. Malic acid and citric acid were dominant among the organic acids for all the cultivars and genotypes except 44-Nrk-05. Glucose was measured as a more abundant sugar than fructose and sucrose in all samples. Antioxidant capacity, on the other hand, varied between 6.17 and 21.13 μmol TE g-1 among the cultivars and genotypes analyzed.

Open access

María C. Ciappini and Fernando S. Stoppani

Abstract

Polyphenolic compounds reportedly produce physiological effects that are beneficial to health. Bee products are particularly rich in polyphenolic compounds. We determined the antioxidant capacity and the phenolic and flavonoid compounds content of 81 samples of honey. We used the Folin-Ciocalteu reagent method to evaluate the total phenolic content. The antioxidant activities were evaluated using in vitro scavenging assays of 2,2-diphenyl-1-picrylhydrazyl (DPPH ) and hydroxyl radicals (OH ), Trolox equivalent antioxidant capacity (TEAC ), and ferric-reducing antioxidant capacity (FRAC ). Total phenolic content ranged from 40.3 to 193.0 mg gallic acid equivalents (GAE )/100 g; the flavonoid content varied from 1.4 to 7.5 mg quercetin equivalents (QE)/100 g. Eucalyptus honeys exhibited significantly higher phenolic content and free radical-scavenging activity than clover honey samples (p<0.05 for all). Principal component analysis explained 73% of the differences observed in antiradical activity with respect to floral origin. Total phenolic content may be more useful than the radical-scavenging assay for detecting antioxidant capacity in honey; it also represents the variable that most appropriately discriminated among these honeys.

Open access

Justyna Chanaj-Kaczmarek, Małgorzata Wojcińska and Irena Matławska

Summary

Coltsfoot leaves (Farfarae folium) are used in the European medicine in respiratory tract diseases, for cough, bronchitis and asthmatic disorders, while in the traditional Chinese medicine only flower buds (Farfarae flos) have been recognized as a medicine. A short literature review shows that most data concern the chemical composition of the coltsfoot flowers. During the carried out studies we have isolated and identified (UV, 1H and 13C NMR, analysis of acid and enzymatic hydrolyze products) six known flavonols from the coltsfoot leaves: kaempferol and its 3-O-β-glucopyranoside and 3-O-α-rhamnopyranosyl(1→6)- β-glucopyranoside, along with quercetin derivatives: 3-O-β-arabinopyranoside, 3-O-β- glucopyranoside and 3-O-α-rhamnopyranosyl(1→6)-β-glucopyranoside. Moreover, we have detected the presence of three phenolic acids.

Open access

S. Fialová, D. Tekeľová, K. Rendeková, J. Klinčok, M. Kolárik, K. Kurucová and D. Grančai

Abstract

Mints rank among the most important Lamiaceae plants. In addition to essential oil, they contain many valuable phenolic compounds, including flavonoids and phenolic acids that participate in mints’ pharmacological properties. In this work, we examined the contents of phenolic compounds variation in the course of 4 years of vegetation. We compared the contents of total hydroxycinnamic derivatives expressed as rosmarinic acid (λ = 505 nm), total polyphenols and tannins expressed as rosmarinic acid (λ = 760 nm), and flavonoids expressed as luteolin-7-O-glucoside (λ = 392 nm) and quercetin (λ = 420 nm) in 1-, 2-, 3-, and 4-year-old plants’ dry leaves, respectively. Spectrophotometric methods of the European Pharmacopoeia were employed. Our results show high levels of active phenolic compounds, particularly in 3- and 4-year-old plants.

Open access

R. Ahmad and A. Srivastava

Abstract

Glutathione S-transferase(s); GST(s) (E.C. 2.5.1.18) are a large family of multifunctional dimeric enzymes that conjugate reduced glutathione to electrophilic centres in hydrophobic organic compounds. GST(s) represent the major class of detoxifying enzymes from parasitic helminths. The GST enzymatic activity has been described in the adult and larval stages of helminths. Several forms and isoforms of the enzyme have been purified and GST genes have also been isolated and expressed as recombinant proteins. The helminth GST(s) participate in detoxification of lipid hydroperoxides and cytotoxic carbonyl compounds produced by oxygen-reactive intermediates (ORIs). The ORIs can come from the endogenous parasite metabolism or from the host immune system. The helminth GST(s) are able to conjugate glutathione to xenobiotic compounds or to bind to the anthelminth drugs. GST is usually found to be localized near to host-parasite interface. This enzyme has been identified as a potentially vulnerable target in immunotherapy and chemotherapy of parasitic diseases. The most effective drug candidates are those based on inhibitors of GST. In the present study, purified GST from cytosolic fraction of bovine filarial worms Setaria cervi was inhibited in a concentration dependent fashion by various compounds such as hemin, ethacrynic acid, S-hexylglutathione, quercetin, cibacron blue, lithocholate sulfate and ellagic acid. Cytosolic GST was inhibited to varying degrees by each inhibitor. In this context, the possible physiological significance of the observed results has been discussed.

Open access

Volkan Okatan

Abstract

Turkey is one of the most important centres of mulberry genetic resources and mulberries grow naturally almost everywhere in Turkey. This study was carried out to determine the most important phenolic compounds and phytochemical properties of mulberry (Morus nigra L.) genotypes collected from natural resources in 2016-2017 in the province of Uşak (Turkey). The investigated biochemical characteristics included: total soluble solids content (TSS), pH, titratable acidity, total phenolic content, vitamin C and antioxidant capacity (DPPH). The highest values of phenolic compounds, i.e. ellagic acid, rutin, quercetin, gallic acid, catechin, chlorogenic acid and caffeic acid, were as follows: 5.89, 133.60, 11.25, 40.90, 10.54, 97.59 and 21.93 g 100 g−1, respectively. The highest values of total phenolics, vitamin C content and antioxidant capacity determined in the investigated mulberry genotypes were 2977.30 mg GAE g−1, 31.34 mg 100 g−1 and 26.80%, respectively. The genotypes 64USA08, 64USA06 and 64USA10 can be recommended in terms of the most valuable chemical composition and used for future breeding purposes. It is desirable to take steps to implement an intensive programme for the preservation of Morus nigra L. biodiversity in Turkey.

Open access

Ot Olaru, Rv Ancuceanu, Adriana Iuliana Anghel, Mihaela Dinu, Oana Cristina Seremet and Viorica Istudor

Abstract

Background: Considering the continuous need to find new sources of polyphenolic compounds, we performed a pharmacognostical examination of the species Fallopia dumetorum (L.) Holub sin. Polygonum dumetorum L. (Polygonaceae). The plant is common in the plain regions of Romania and has not been exploited therapeutically.

Materials and method: Microscopic examination was performed on cross-sections, surface preparations and on powder obtained from the aerial parts of the flowering plant. Qualitative chemical analysis was realized by phytochemical screening and thin layer chromatography (TLC). Phenolic compounds were assayed by spectrophotometric methods: flavonoids expressed as rutin (with aluminium chloride), phenolcarboxylic acids expressed as chlorogenic acid (Arnow’s method) and proanthocyanidins expressed as cyanidin chloride (in acidic medium, by conversion to anthocyanins).

Results: The species has the following microscopic characters: anomocytic stomata, druses of calcium oxalate, sessile, pluricellular glandular hairs and pollen grains with smooth exine. Polysaccharides, reducing compounds, coumarins, sterols/triterpenes, phenol-carboxylic acids, flavones, proanthocyanidins, tannins and carotenoids were identified by phytochemical screening; chlorogenic acid, caffeic acid, quercetin and stigmasterol/beta-sitosterol were detected by TLC. F. dumetori herba has a content of 1.49 ± 0.105 g% polyphenol-carboxylic acids, 0.40 ± 0.087g% flavonoids and 0.18 ± 0.002 g% proanthocyanidins.

Conclusions: We have characterized pharmacognostically the native species F. dumentorum. Due to its content in phenolic compounds it might serve as a source of polyphenols.

Open access

Mariia Shanaida, Olena Golembiovska, Nataliia Hudz and Piotr P. Wieczorek

Abstract

The present investigation was to estimate the total phenolic content and composition of flavonoids and hydroxycinnamic acids in herbal infusions obtained from aerial parts of three Lamiaceae species (Dracocephalum moldavica, Ocimum americanum and Satureja hortensis). The total phenolic content of herbal infusions was determined using a spectrophotometric method, whereas the individual phenolics were assessed by high-performance liquid chromatography (HPLC). The HPLC method was developed and validated. The total phenolic content was measured by applying the Folin-Ciocalteu method with reference to gallic acid. Results were in the range from 29.39 to 65.38 mg estimated as gallic acid equivalents per gram of dry herb. The phenolic profile was, in turn, analysed by HPLC and consisted of gallic acid, hydroxycinnamic acids (caffeic, chlorogenic, ferulic, and rosmarinic) and flavonoids (rutin, hyperoside, quercitrin, quercetin, apigenin, apigenin-7-glucoside and catechin) in different concentrations. Rosmarinic acid was the predominant component among the hydroxycinnamic acids in herbal infusions of all three plants. This was found to be in the range of 3.64 to 5.28 mg per gram of dry herb. Apigenin-7-glucoside, quercitrin and hyperoside were the prevailing flavonoid components of the infusions.

Open access

Zuzana Kyselova

involved in the dissimilar myocardial and coronary effects elicited by quercetin and myricetin, two red wine flavonols. Nutr Metab Cardiovasc Dis   21 (5): 362-371. Baraldo M. (2008). The influence of circadian rhytms on the kinetics of drugs in humans. Expert Opin Drug Metab Toxicol   4 (2): 175-192. Barjesteh van Waalwijk van Doorn-Khosrovani S, Janssen J, Maas LM, Godschalk RW, Nijhuis JG and Schooten FJ. (2007). Dietary flavonoids induce MLL translocations in primary human CD34+ cells. Carcinogenesis   28 : 1703