Influence of Phytochemical Reductive Capacity on Ultraviolet–visible Spectroscopic Behavior of Silver Nanoparticles

ABSTRACT

A widely used method for obtaining silver nanoparticles uses plant extracts for reduction because of the presence of phytochemicals such as terpenoids, tannins, and flavonoids. Extracts of Flores sambuci, Hypericum perforatum, Lavandula angustifolia, Origanum vulgare, Rosmarinus officinalis, and Salvia officinalis were used for generating silver nanoparticles. The ultraviolet–visible spectra of silver nanoparticle solutions were correlated with variations of phytochemical characteristics to evaluate the plant extracts. These parameters were the antioxidant activity, total flavonoids, total tannins, total terpenoids, and total phenolics. Correlations between measurements of extracts’ phytoreductive characteristics were explained using Pearson coefficients. The results showed medium linear positive correlations for total tannins with the spectra of silver nanoparticle solutions. The antioxidant activity and total terpenoids presented medium linear negative correlations. Pearson coefficients between total phenolics and relative areas from ultraviolet–visible spectra from 350 to 600?nm were close to zero indicating no linear correlation.     

Evaluation of the antioxidant and anti-inflammatory activities of solvent extracts of Tricholepis chaetolepis (Boiss) Rech. f. whole plant

Abstract

The whole plant, Tricholepis chaetolepis, powder was investigated using proximate and fluorescence analysis along with determining the extractive values. Total phenolics, flavonoids and total protein contents of n-hexane, chloroform and methanolic extracts of the whole plant were also determined. The anti-diabetic activity of all the three extracts of the plant was determined by in vitro alpha-amylase inhibition assay. The anti-oxidant potential was evaluated using Phosophomolybdenum and DPPH methods. The anti-inflammatory potential of all extracts were determined by carrageenan-induced rat paw oedema model. The evaluation of the plant extracts exhibited the anti-diabetic, anti-oxidant, and anti-inflammatory activities in dose dependent fashion. The research concludes that Tricholepis chaetolepis extracts contain phenol, flavonoids, and tannins that show observable anti-oxidant and anti-diabetic potential. It is also concluded that the methanol extract of the plant showed the maximum effect against inflammation induced by carrageenan in rat paw oedema as compared with n-hexane and chloroform extracts.     

Enhancement of phenolic and flavonoids compounds,antioxidant and cytotoxic effects in regenerated red cabbage by application of Zeatin

Abstract

This study evaluated the roles of zeatin (2?mg/L) on direct organogenesis, phytochemical compounds, antioxidant activity, and cytotoxic activity in regenerated shoots of red cabbage. The results revealed that the extract of explant treated by 2?mg/L zeatin gives the highest content of total phenolics (5.18?mg gallic acid equivalent/g dry weight) and flavonoids (1.52?mg rutin equivalent/g dry weight). Moreover, HPLC and GC-MS analyses indicated that various bioactive compounds in red cabbage are significantly enhanced with increasing zeatin concentration. Besides that, antioxidant activity test showed that in vitro shooting culture using 2?mg/L zeatin displayed higher antioxidant activity in all assays (DPPH, FRAP and ABTS) compared to control with respective values of 68.12%, 73.28%, and 54.1%, respectively. Finally, the cytotoxic properties illustrated that the extracts of red cabbage explant treated by 2?mg/L zeatin exhibited the strongest cytotoxic effect towards cancer cells compared to control.     

Chemical characterization of constituents from Polygonatum cyrtonema Hua and their cytotoxic and antioxidant evaluation

Abstract

Twenty-four compounds were isolated from the roots of Polygonatum cyrtonema Hua, including a new octopamine dimer, named trans-bis(N-feruloyl)octopamine (1). The structure was established on the basis of spectroscopic and chemical methods. All the extracts and compounds were evaluated for cytotoxic and antioxidant activities by using MTT and chemiluminescence assay. The extracts showed activity against MCF-7 and HepG-2 cell lines from IC₅₀ 0.30 to 1.01 mg mL^?1. Compound 3 exhibited activity against HepG-2 cell lines with IC₅₀ 8.99?μM. Compound 7 exhibited activity against Hela cell lines with IC₅₀ 2.53?μM and BGC-823 cell lines with IC₅₀ 7.77?μM. Moreover, compound 7 showed antioxidant with IC₅₀ 12?µM compared to the positive control with IC₅₀ 77?µM. Compound 16 exhibited activity against HepG-2 cell lines with IC₅₀ 1.05?μM and MCF-7 cell lines with IC₅₀ 1.89?μM. These results indicated that this plant might be potential in natural medicine and healthy food.     

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.     

Two nematicidal furocoumarins from Ficus carica L. leaves and their physiological effects on pine wood nematode (Bursaphelenchus xylophilus)

The ethanol extract of the Ficus carica L. leaves was tested to show strong nematicidal activity against pine wood nematode (PWN), Bursaphelenchus xylophilus, causing 90.93% corrected mortality within 72 h at 1.0 mg/mL. From the ethyl acetate soluble fraction of the F. carica L. leaves extract, the main nematicidal constituents were obtained by bioassay-guided isolation and identified as linear furocoumarins bergapten (1) and psoralen (2) by mass and NMR spectral data analysis. Bergapten and psoralen had significant nematicidal activity against PWN with the LC₅₀ values of 97.08 aKSnd 115.03 μg/mL within 72 h, respectively. The two furocoumarins could inhibit the activities of amylase, cellulase and acetylcholinesterase (AchE) from PWN. The morphologies of PWNs changed much after they were treated by bergapten and psoralen. The physiological effects of bergapten and psoralen on PWN might provide helpful clues to elucidate their nematicidal mechanisms.     

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.     

Study on the stability of supercritical fluid extracted rosemary (<Emphasis Type="Italic">Rosmarinus offcinalis</Emphasis> L.) essential oil

The aim of this study was to examine the influence of storage conditions and duration on composition and antioxidant activity of supercritical fluid (SCF) extracted essential oil of rosemary (Rosmarinus officinalis L.). Supercritical extraction was carried out sequentially by using SCF carbondioxide in the first two steps and with 5% ethanol as entrainer in the third step. The compositions of the extracts were determined by gas chromatography/mass spectrometry. The total phenolics were analyzed using Folin-Ciocalteau assay. Antioxidant activities of the extracts were tested by β-carotene-linoleic acid bleaching method.     

Inula viscosa (L.) Aiton leaves and flower buds: Effect of extraction solvent/technique on their antioxidant ability,antimicrobial properties and phenolic profile

Abstract

This study was designed to establish the most effective solvent/technique for extracting antioxidant phytoconstituents from leaves and flower buds of Inula viscosa (L.) Aiton (Asteraceae) grown wild in Morocco. Maceration and hot extraction with methanol or water and Soxhlet ethanol extraction were utilized. The antioxidant potential was evaluated in vitro by DPPH, reducing power, and ferrous ions chelating activity assays. I. viscosa leaf and flower bud extracts displayed the strongest effect in the DPPH test, being the Soxhlet ethanol the most active ones (IC₅₀ = 54.24?±?0.21?μg/mL and 39.77?±?0.23?μg/mL); thus, they were selected for further investigations. The antimicrobial efficacy of the Soxhlet ethanol extracts against ATCC and food isolates strains was assayed; the leaf extract showed the best activity, and Candida albicans was the most sensitive strain (MIC = 125?µg/mL). The extracts resulted non-toxic against Artemia salina. Among the phenolics characterised by HPLC-PDA-ESI-MS, hispidulin hexoside, patuletin and spinacetin were identified for the first time.     

Shelf Life Extension and Quality Improvement of Cucumber Slices Impregnated in Infusions of Edible Herbs

Abstract

Development of functional food through their enrichment with herbal extracts is gaining much attention from the food industry. The present study evaluates the benefits, such as the oxidative stability and quality retention, of the enrichment of cucumber (Cucumis sativus) with natural phenolic compounds through immersion into a variety of herbal infusions. After a preliminary experiment with gallic acid solutions, the beneficial effect of hypotonic solutions was observed and the optimal process conditions were defined. The second step of the study involved the immersion of cucumber in the herbal infusions for 2.5?h at 70?°C. The total phenolic content (TPC), antiradical and antioxidant activity of osmo-treated slices were determined to evaluate the extent of bioactive compounds’ impregnation. During the immersion, TPC, antioxidant and antiradical activity significantly increased irrespective of the type of the herbal infusion. The TPC varied greatly, ranging from 1.41 to 781.14?mg GAE/kg of cucumber. The highest total phenolics were found in cucumber treated with Origanum vulgare infusion, followed by Jasminum officinale and Mentha spicata infusions. The aforementioned osmo-treated slices were also highly appreciated by the sensory panel; therefore, for those best performing herbal infusions, the third phase of this work involved the study of quality degradation under subsequent storage of the osmo-treated slices vs. the untreated ones. The results regarding color, texture, and visual assessment demonstrated the superior quality retention of the osmo-treated samples that exhibited a shelf life extension ranging from two- to almost four-fold compared to the untreated tissue.     

Chemical composition and antioxidant activity of Borago officinalis L. leaf extract growing in Algeria

The aqueous and hydroalcoholic extracts of borage (Borago officinalis) leaves from Annaba region (Algeria) were preliminary analyzed for their phenolic profile (total phenolics, total flavonoids, total flavonols, total tannins and total anthocyanins). These extracts were evaluated for their antioxidant properties by different methods such as DPPH radical scavenging, test NBT and total antioxidant activity. The two extracts have exhibited a high antiradical capacity. Indeed, the ethanolic extract showed the lower IC50 values and the highest amount of phenolics (94.09 ± 1.72 mg gallic acid/g dry extract). Using LC-MS/MS analysis, it was possible to identify phenolic acids, flavonoids, sterol and for the first time oleuropein was identified in the aqueous extract of the plant. The obtained results have demonstrated that phenolic compounds are the major contributor to the antioxidant activity of plants.     

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.     

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.     

Phytochemical composition,antioxidant activity and HPLC profiles of Swertia species from Western Ghats

Swertia chirayita is one of the potential medicinal plants of the family Gentianaceae in traditional medicine. Due to its high demand and scarcity, trade of chirayita is affected by adulterants. Swertia species from Western Ghats were compared with S. chirayita for phytochemical characterisation and antioxidant activities by using different extracts. This study revealed that acetone is the best extraction solvent of phenolic and flavonoid compounds with antioxidant properties as compared with other extracts. S. chirayita showed better antioxidant activity than other species with highest content of phenolics and flavonoids. Among the species from Western Ghats, Swertia minor has better antioxidant properties with higher content of phenolics and flavonoids when compared with S. chirayita. Gallic acid was detected in all species under study by using HPLC analysis. The Swertia species under study showed similar phytochemical properties and antioxidant potential and hence their use as substitute to S. chirayita needs to be further investigated.     

Synthesis,characterization, and biological evaluation of indole aldehydes containing N-benzyl moiety

Abstract

The present study describes the synthesis, characterization and biological evaluation of N-benzyl indole aldehydes. The biological activities of the newly synthesized compounds were examined by investigating their antioxidant and anti-inflammatory activities. The potential of these compounds as an antioxidant was determined by 2,2-diphenylpicrylhydrazyl, Nitric oxide, Superoxide, peroxide radical scavenging methods. We found that aldehydes 4a, 4b, 4c, and 4e and shows promising in vitro DPPH scavenging antioxidant activity while aldehyde 4b and 4e show good in vitro anti-inflammatory activity.     

Microwave-Assisted Efficient Extraction and Stability of Juglone in Different Solvents from Juglans regia: Quantification of Six Phenolic Constituents by Validated RP-HPLC and Evaluation of Antimicrobial Activity

Abstract

In the present study, microwave-assisted extraction was compared with conventional approaches for the efficient extraction of juglone and other phenolics from Juglans regia bark. The effect of different solvents was also studied and ethyl acetate was found to be a better solvent in terms of juglone yield and stability. Further, a simple and fast RP-HPLC method was developed and validated for the determination of juglone and other bioactive phenolics like gallic acid, caffeic acid, quercetin, myricetin, and quercitrin in these extracts. In addition, the extracts were tested for antimicrobial activity against 16 microorganisms where all the extracts showed broad spectrum activity.     

A new norisoprenoid from the leaves of Ficus pumila

One new norisoprenoid 3,9-dihydroxy dihydro actinidiolide (1), together with eleven known compounds (2–12), were isolated from ethanol extract of the leaves of Ficus pumila collected in Hainan Province, China. Their structures were elucidated by the detailed analysis of comprehensive spectroscopic data. Compounds 1, 2, 4, 5, 8 and 10–12 were isolated from the F. pumila for the first time. All compounds were evaluated for their cytotoxic activity. Compounds 3 and 9 showed weak cytotoxic activity against Hela, MCF-7 and A549 cell lines.     

Chemical profile and biological activities of Peltigera horizontalis (Hudson) Baumg. thallus and apothecia extracts

Abstract

The aim of this study was to determine, for the first time, the chemical composition of Peltigera horizontalis thallus and apothecia extracts (ether, ethyl acetate, dichloromethane and acetone) by HPLC-UV and GC-MS, and evaluate activity of genotoxic, anticholinesterase, antioxidant and antibacterial potential of acetone extracts. Major constituents of thallus extracts were gyrophoric acid, and methyl gyrophorate while dominant component of apothecia extracts was tenuiorin. The predominant volatile compounds in extracts were methyl orsellinate, dodecyl acrylate, orcinol and orcinol monomethyl ether. The thallus acetone extract at concentration of 2.0 µg mL^?1 gave the greatest decrease in the micronuclei frequency (22.4%) of all tested extracts. Apothecia extract showed stronger antioxidant activity as compared to thallus extract. Tested extracts at concentration of 10?mg mL^?1 exhibited inhibitory effect (16.5% for thallus and 12.8% for apothecia) on pooled human serum cholinesterase. P. horizontalis acetone extracts had no activity against the tested five bacteria strains.     

Stability indicating HPLC method for the simultaneous determination of moxifloxacin and prednisolone in pharmaceutical formulations

Background

Obtaining new pharmaceutical materials with enhanced properties by using natural compounds and environment-friendly methods is a continuous goal for scientists. Ficaria verna Huds. is a widespread perennial plant with applications in the treat of haemorrhoids and to cure piles; it has also anti-inflammatory, astringent, and antibiotic properties. The goal of the present study is the obtaining and characterization of new F. verna extract/??-cyclodextrin complexes by using only natural compounds, solvents, and environment-friendly methods in order to increase the quality and acceptability versus toxicity indicator. Thus, the flavonoid content (as quercetin) of Ficaria verna Huds. flowers and leaves from the West side of Romania was determined and correlated with their antioxidant activity. Further, the possibility of obtaining ??-cyclodextrin supramolecular systems was studied.

Results

F. verna flowers and leaves extracts were obtained by semi-continuous solid-liquid extraction. The raw concentrated extract was spectrophotometrically analyzed in order to quantify the flavonoids from plant parts and to evaluate the antioxidant activity of these extracts. The F. verna extracts were used for obtaining ??-cyclodextrin complexes; these were analyzed by scanning electron microscopy and Karl Fischer water titration; spectrophotometry was used in order to quantifying the flavonoids and evaluates the antioxidant activity. A higher concentration of flavonoids of 0.5% was determined in complexes obtained by crystallisation method, while only a half of this value was calculated for kneading method. The antioxidant activity of these complexes was correlated with the flavonoid content and this parameter reveals possible controlled release properties.

Conclusions

The flavonoid content of F. verna Huds. from the West side of Romania (Banat county) is approximately the same in flowers and leaves, being situated at a medium value among other studies. ??-Cyclodextrin complexes of F. verna extracts are obtained with lower yields by crystallisation than kneading methods, but the flavonoids (as quercetin) are better encapsulated in the first case most probably due to the possibility to attain the host-guest equilibrium in the slower crystallisation process. F. verna extracts and their ??-cyclodextrin complexes have antioxidant activity even at very low concentrations and could be used in proper and valuable pharmaceutical formulations with enhanced bioactivity.     

Complimentary Role of Micellar Electrokinetic Capillary Chromatography and High Performance Liquid Chromatography in the Separation of Plant Phenolics

Abstract

A comparison was made between the efficiency of micellar electrokinetic capillary chromatography (MECC) and reversed phase high performance liquid chromatography (RP-HPLC) to separate a mixture of plant phenolics. Of a range of buffers 6 mM borate/10 mM phosphate/100 mM SDS at pH 8.5 was the most effective in separating a complex mixture of phenolics using MECC. Using this buffer the elution order and resolution was different from that obtained by HPLC using a reversed phase C18 column. These results illustrate how MECC and RP-HPLC are complimentary when examining complex mixtures such as those obtained from plant extracts. MECC using these conditions was applied to the examination of phenolics from leaf tissue of Eucalyptus margmata (jarrah).