Quantification Of Phenolic Compounds Research Articles

Characterization and quantification of phenolic compounds of Argania spinosa leaves by HPLC-PDA-ESI-MS analyses and their antioxidant activity

Characterization and quantification of phenolic compounds of Argania spinosa leaves by HPLC-PDA-ESI-MS analyses and their antioxidant activity

Identification and Quantification of Phenolic Compounds of Tunisian Rosmarinus officinalis L.

Identification and Quantification of Phenolic Compounds of Tunisian Rosmarinus officinalis L.

Antifungal and antichemotactic activities and quantification of phenolic compounds in lipophilic extracts of Hypericum spp. native to South Brazil

Plants of the Hypericum genus are a notable source of new therapeutic agents including antimicrobial and anti-inflammatory. This study reports the antifungal and antichemotactic activities of the lipophilic extracts of five Hypericum species (H. caprifoliatum Cham. & Schlecht., H. carinatum Griseb., H. linoides A. St.-Hil., H. myrianthum Cham. & Schlecht. and H. polyanthemum Klotzsch ex Reichardt) native to South Brazil. Tests were performed using the broth microdilution assay against 10 species of pathogenic yeasts and neutrophils migration inhibition method, respectively. All samples exhibited a broad spectrum of antifungal action as well as reduced neutrophils migration. H. carinatum, H. linoides and H. myrianthum extracts presented the lowest value of minimum inhibitory concentration against Cryptococcus neoformans (MIC≤15.6μg/mL), Rhodotorula mucilaginosa (MIC≤62.5μg/mL), Candida glabrata and Candida tropicalis (MIC range=1.9–250μg/mL). The antichemotactic effect varied from 60 to 100% at concentrations of 0.31–10.0μg/mL. The results of analyses by HPLC demonstrated a strong correlation between the phenolic compounds and the antifungal/anti-inflammatory activities. The extracts that presented high amounts of the dimeric phloroglucinol uliginosin B, japonicin A and hyperbrasilol B were the most active. Thus, Hypericum extracts show potential as source of new anti-infectives and anti-inflammatory drugs.

Determination of phenolic compounds and authentication of PDO Lambrusco wines by HPLC-DAD and chemometric techniques

This work proposes a fast and simple method for detection and quantification of phenolic compounds in PDO Lambrusco wines using HPLC-DAD and chemometric techniques. Samples belonging to three different varieties of Lambrusco (Grasparossa, Salamino and Sorbara) were analyzed to provide a methodology appropriate for routine analysis. Given the high complexity of the sample and the coelution among chromatographic peaks, the use of chemometric techniques to extract the information of the individual eluting compounds was needed. Multivariate curve resolution-alternating least squares (MCR-ALS) allowed the resolution of the chromatographic peaks obtained and the use of this information for the quantification of the phenolic analytes in the presence of interferences. Use of multiset analysis and local rank/selectivity information was proven to be crucial for the correct resolution and quantification of compounds. The quantitative data provided by MCR-ALS about the phenolic targets and additional compounds present in the samples analyzed provided wine composition profiles, which were afterwards used to distinguish among wine varieties. Principal component analysis applied to the wine profiles allowed characterizing the wines according to their varieties.

An improved mass spectrometric method for identification and quantification of phenolic compounds in apple fruits

Thirty-nine phenolic compounds were analysed using ultra high performance liquid chromatography (UHPLC) coupled with diode array and accurate mass spectrometry detection using electrospray ionisation (DAD/ESI-am-MS). Instrumental parameters such as scan speed, resolution, and mass accuracy were optimised to establish accurate mass measurements. The method was fully validated in terms of model deviation (r2>0.9990), range (typically 10–3500ngg−1), intra/inter-day precision (<6% and <8%, respectively) and accuracy (typically 100±10%). The mass accuracy of each selected phenolic compound was below 1.5ppm. The results confirmed that the UHPLC-DAD/ESI-am-MS method developed here was convenient and reliable for the determination of phenolic compounds in apple extracts.

Identification, characterisation, and quantification of phenolic compounds in the antioxidant activity-containing fraction from the seeds of Korean perilla (Perilla frutescens) cultivars

The present research was the first to investigate phenolic compound profiles and antioxidant properties in the seeds of various perilla (Perilla frutescens) cultivars. The 80% methanol extract (50μg/ml) of this species showed potent antioxidant activities against 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) radicals. Phenolic compounds were characterised by nuclear magnetic resonance (NMR) spectroscopy, and ultra performance liquid chromatography with photodiode array detector and electrospray ionisation/mass (UPLC-PDA-ESI/MS) analysis. Nine compounds were elucidated as caffeic acid-3-O-glucoside (1), caffeic acid (2), luteolin-7-O-glucoside (3), apigenin-7-O-glucoside (4), rosmarinic acid-3-O-glucoside (5), rosmarinic acid (6), luteolin (7), apigenin (8), and chrysoeriol (9). The individual and total phenolic contents were remarkably different, especially rosmarinic acid-3-O-glucoside (5) and rosmarinic acid (6) which were the predominant compounds (>95%) in all perilla cultivars. Additionally, Yeupsil cultivar exhibited the highest phenolic content (5029.0μg/g) and antioxidant activity, whereas the lowest was shown by Dasil (2138.7μg/g). Therefore, these results suggest that antioxidant effects of perilla seeds are correlated with phenolic contents.

Buckwheat (Fagopyrum esculentum Moench) Grain and Fractions: Antioxidant Compounds and Activities

Buckwheat (Fagopyrum esculentum Moench) is an alternative crop belonging to the Polygonaceae family. In comparison to antioxidant activity of frequently used cereals, buckwheat has been reported to possess higher antioxidant activity (AOA), mainly due to high rutin content. The objective of this work was to determine the main antioxidant compounds and AOA of buckwheat grain fractions (whole grain, hull, and groat). Buckwheat grain fractions were extracted with ethanol/water (80/20, v/v), followed by determination of total phenolic and flavonoid content. Quantification of phenolic compounds and tocopherols was performed by high-performance liquid chromatography (HPLC). The AOA was estimated by 2 direct electron spin resonance (ESR) and 4 indirect (spectrophotometric) tests. Significantly higher contents of total phenolics and total flavonoids were found in buckwheat hull than in whole grain and groat. Protocatechuic, syringic, and sinapic acid, rutin, and quercetin were found in all tested fractions, whereas vanilic acid was found in whole grain and hull. The content of total tocopherols in investigated samples ranged from 23.3 mmol/g for hull to 61.8 mmol/g for groat. Hull was superior in scavenging activity on 1,1-diphenyl-2-picrylhydrazyl (DPPH(•)), hydroxyl ((•)OH), and superoxide anion (O(2)(•-)) radicals, reducing activity, AOA by β-carotene bleaching method, and chelating activity on Fe(2+) as evidenced by its lower IC(50) value. Obtained results can broaden the utilization of buckwheat, especially a share of hull in whole grain flour production. Obtained results suggest possibility to supplement the whole grain buckwheat flour with hull, which leads toward better usage of by-products in buckwheat production, and enhancement of antioxidant potential of the final product.

Efeito dos resíduos de café seco e fermentado por Monascus ruber no metabolismo de camundongos Apo E

Atherosclerosis is a chronic inflammatory disease of multifactorial origin, which occurs in response to endothelial injury. The fungus Monascus ruber has hypocholesterolemic activity, and the polyphenols present in coffee residue have an antioxidant activity and can help prevent cardiovascular diseases. Coffee residue has a significant amount of fermentable sugars, being an adequate substrate for growing fungi. The objective of this study was to assess the effect of dry coffee residue fermented with Monascus ruber on the lipid metabolism of ApoE knockout mice. The biological assay was performed with 30 ApoE knockout mice, divided into five groups and undergoing different treatments. The phytochemical prospection and quantification of phenolic compounds of the fermented and non-fermented coffee residues were performed. The sera of the animals were analyzed by using enzyme kits, and the aortic tissue was embedded in paraffin and stained with hematoxylin and eosin to undergo histopathological analysis. Comparing with the control group, the group receiving 2% non-fermented coffee residue showed a reduction of 42% in the serum levels of triacylglycerols and of approximately 41% in VLDL-c. The groups receiving 10% non-fermented coffee residue and 2% fermented coffee residue showed reductions in the lesion areas of 10.5% and 15.4%, respectively, as compared with the control group. The fermented coffee residue showed a higher content of phenolic compounds as compared with the non-fermented coffee residue. The present study showed that coffee residue fermentation has a potentially beneficial effect on cardiovascular diseases, especially atherosclerosis.

Quantification of phenolic compounds by capillary zone electrophoresis in extracts of four commercial types of mate herb before and after acid hydrolysis

Mate herb, Ilex paraguariensis St. Hil., is a plant cultivated in South America. Studies have evidenced the presence of phenolic compounds in mate herb, however, there are no reports on the contents of these compounds in different types of mate herb sold in the South Region of Brazil. In this study, capillary zone electrophoresis was used to quantify phenolic compounds in three lots of each of four types of commercial mate herb (traditional, native, large ground, and suave). Analysis was performed before and after acid hydrolysis. Hydrolysis time, temperature and chloridric acid concentration were optimized by central composite design to maximize the amounts of free phenolic compounds obtained after hydrolysis. Before hydrolysis, high amounts of rutin were detected, while after hydrolysis, high amounts of caffeic acid and 3,4-dihydroxybenzoic acid were obtained, giving evidence that mate herb should be further investigated as a major source of these compounds.

Anti-ulcer polysaccharides from Cola cordifolia bark and leaves

Ethnopharmacological relevanceAqueous extracts of bark and leaves of C. cordifolia are traditionally used in Mali (West Africa) in the treatment of wounds and gastric ailments like abdominal pain, gastritis and gastric ulcers. Aim of the studyTo evaluate and compare the anti-ulcer and immunological activities, as well as the toxicity of polysaccharide rich water extracts from the bark and leaves of C. cordifolia. Materials and methodsGastric ulcers were induced in rats and the inhibition of ulcer formation was calculated based on lesion index. Immunological activities were measured by complement fixation and macrophage activation. Toxicity was tested on brine shrimps. The two extracts were characterised by GC, Yariv-precipitation and quantification of phenolic compounds. An ethnomedical survey on C. cordifolia was carried out in Siby (Mali, West-Africa) to generate more knowledge about the traditional use. ResultsBark and leaf extracts from C. cordifolia significantly inhibited the formation of gastric lesions in rodents in a dose depending manner. CCbark50 showed a high complement fixation activity in vitro. No toxicity was found. The ethnomedical survey showed that C. cordifolia was mainly used for treating pain and wounds. ConclusionsOur results shows that the bark and the leaves comprise a dose dependant anti-ulcer activity in an experimental rat model (no statistical difference between the plant parts). Clinical studies should be performed to evaluate the effect of both bark and leaves of C. cordifolia as a remedy against gastric ulcer in human.

Determination of Phenolic Compounds in Strawberries (Fragaria ananassa Duch) by High Performance Liquid Chromatography with Diode Array Detection

This paper describes a method for simultaneous identification and quantification of phenolic compounds in strawberries followed by a reversed-phase high performance liquid chromatography (HPLC) with diode array detection. The studied phenolics were flavonoids (flavonols: quercentin, rutin, and kaempferol; flavanols: catechin and epicatechin; anthocyanidins: cyanidin and pelargonidin) and phenolic acids (hydroxybenzoic acid derivatives: gallic and ellagic acids; hydroxycinnamic acid derivatives: ferulic, coumaric, and cinnamic acids). The mobile phase consisted in a gradient prepared from formic acid in water (2 %, pH 3) and formic acid in methanol (2 %, pH 3), flow rate 0.7 mL min−1 at 25 °C. Analyses were performed, using methanol as extractant, before and after acid hydrolysis with the aim of determining free and conjugated phenolic compounds in strawberries. The acid hydrolysis conditions (6 mol L−1 HCl, 50 min at 90 °C) were shown to be suitable both for phenolic standards and strawberry extracts. Method validation, using phenolic standard solutions, included: linearity study, limits of detection and quantification, and calibration and analytical sensitivity quantifications. Precision and accuracy were studied in strawberry extracts. The results indicate that the developed method was linear, sensible, precise, and accurate, and the convenience of methanol can substitute acetonitrile as the most commonly used solvent in HPLC. The method was employed for knowing the phenolic profile in seven strawberry cultivars from Italy and Argentina, and besides, total phenolic content was analyzed by the Folin–Ciocalteu method; the total antioxidant activity was investigated using the ABTS method. Good correlations were observed among latter parameters, and total phenolics were obtained as the sum of each phenolic compound analyzed by photodiode array detection-HPLC.

Biosensor employing screen‐printed PEDOT:PSS for sensitive detection of phenolic compounds in water

AbstractPoly(3,4‐ethylenedioxythiophene) (PEDOT) and its derivatives are relatively new, and unique members of conducting‐polymers family. In this article, we present an approach for simple, reliable and cost‐efficient electrochemical biosensor for real‐time detection and quantification of phenolic compounds (PhCs). The PEDOT:poly(styrene sulfonate) (PSS) polymer, directly screen‐printed on the surface of the working electrode, was shown to act as an effective electrical conductor but also as an efficient redox mediator. It has also been found suitable for the reduction of quinone ions at low reducing potentials, close to 0 V versus Ag/AgCl, thus minimizing interferences due to other electroactive species present in real samples. Based on these properties, a biosensor based on tyrosinase immobilized on PEDOT:PSS‐modified electrodes was developed allowing the detection of PhCs in surface waters. The biosensor displayed very good performance in terms of sensitivity, detection limit and linear range. Assays using surface water previously spiked with bisphenol A showed that the biosensor was able to detect PhCs in real conditions with no matrix effect. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012

Characterization and storage stability of the extract of Thai mango (Mangifera indica Linn. Cultivar Chok-Anan) seed kernels.

Qualitative analysis of hydrolysable extract from mango (Mangifera indica Linn. cultivar Chok-Anan) seed kernel was performed by means of reversed phase high-performance liquid chromatography coupled to diode array detection and electrospray ionization mass spectrometry (RPHPLC-DAD-ESI-MS). The main phenolic compound was identified as methyl gallate by comparing their retention time, UV-vis absorption spectra and mass spectra with a reference standard. Quantification of phenolic compounds was performed by HPLC-DAD, which revealed that the extract contained total phenolics at a concentration of 194.1mg GAE/g dry weight of mango seed kernel (MSK), of which 85.7% was identified as methyl gallate. In addition, the antioxidant activities of the extract and the main compound were assessed by the 2,2-diphenyl-1-picrylhydrazyl and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) assays, by the ferric thiocyanate method and by an assay of metal chelating activity. Tyrosinase inhibition was also investigated. Furthermore, the antioxidant capacity and the total phenolic content of MSK extract stored in a plastic (polyethylene) PE bag decreased during storage at freezing (-20°C), refrigerated (7°C) and room (28-32°C) temperature for 182days. The loss of antioxidant capacity and total phenolic content increased at higher storage temperatures for more than 182days.

Comparative phenolic profile of Persian walnut (Juglans regia L.) leaves cultivars grown in Iran

In this study Walnut leaves from 11 different cultivars (Mayette, Fernor, Mellanaise, Elit, Orientis, Lara, Hartley, Franquette, Parisienne, Arco and Marbot) were studied for their phenolic compounds. The evolution of major phenolic compounds amounts was monitored from May to September. Two extractive procedures were assayed and the best results were obtained using acidified water (pH 2) and a solid phase extraction column purification step. Qualitative analysis was performed by HPLC-DAD/MS and, in all samples; nine phenolic compounds (3-caffeoylquinic, 3-p-coumaroylquinic and 4-p-coumaroylquinic acids, quercetin 3-galactoside, quercetin 3-arabinoside, quercetin 3-xyloside, quercetin 3-rhamnoside, quercetin 3-pentoside and kaempferol 3-pentoside) were identified. Quantification of phenolic compounds was performed by HPLC-DAD, which revealed that quercetin 3-galactoside was always the major compound while 4-p-coumaroylquinic acid was the minor one. All cultivars presented slightly higher values of total phenolic compounds in May and July. Key words: Juglans regia L., phenolic profile, walnut leaf, high performance liquid chromatography -diode array detector (HPLC-DAD), high performance liquid chromatography/ diode array detector-electrospray ionization- mass spectrometry (HPLC/DAD/ESI-MS).

Antioxidant activity and phenolic composition of brazilian honeys and their extracts

The antioxidant activities and total polyphenolic content of five multifloral and four orange blossom Brazilian honey samples and their phenolic extracts were investigated. Identification and quantification of phenolic compounds were carried out by HPLC-DAD (high-performance liquid chromatography with diode-array detection). The radical scavenging activities, determined with 2,2-diphenyl-1-picrylhydrazyl (DPPH•) and expressed as EC50, ranged from 10.81 to 52.64 mg mL-1 for honey and 6.17 to 52.87 mg mL-1 for the extracts. The extract antioxidant activities were also determined by 2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) and ferric reducing antioxidant power (FRAP) assays, and the results varied from 46.53 to 383.49 mmol TE 100 g-1 and 34.99 to 408.14 mol Fe(II) 100 g-1, respectively. It was also evaluated the total phenolic and flavonoid contents by the Folin-Denis and aluminum chloride methods, respectively. Antioxidant activities and total phenolic contents were found to be highly correlated.

Optimisation of the microwave‐assisted extraction process for six phenolic compounds in Agaricus blazei murrill

SummaryAn efficient microwave‐assisted extraction (MAE) technique was employed in the extraction of phenolic compounds from Agaricus blazei murrill, and phenolic compounds were quantified by High‐performance liquid chromatography (HPLC). The MAE procedure was optimised, validated and compared with other conventional extraction techniques. MAE gave the best result because of the highest extraction efficiency within the shortest extraction time. The optimal conditions of MAE were 60% ethanol, ratio of solid/liquid 1:30, temperature 110 °C, irradiation power 500 W and three extraction cycles, each 5 min. This is the first report on combining MAE with HPLC for the extraction and quantification of phenolic compounds in A. blazei murrill. The developed MAE method provided a good alternative for the extraction of phenolic compounds in A. blazei murrill as well as other materials.

Quantification of Phenolic Compounds during Red Winemaking Using FT-MIR Spectroscopy and PLS-Regression

We present a rapid method to quantify phenolic compounds all during the red winemaking process using Fourier transform mid-infrared (FT-MIR) spectroscopy and chemometrics. To get the reference values, we used the usual UV–vis spectroscopy methods, and the compounds studied were evaluated as total phenolic compounds (TPC), total anthocyanins (TA), and condensed tannins (CT). Sampling from five different grape varieties (Merlot, Tempranillo, Syrah, Cariñena, and Cabernet sauvignon), harvested at different ripening states, and monitored over 10 days of vinification produced a total of 600 spectra. These were used to build and validate four different predictive models by partial least-squares (PLS) regression. The spectral regions selected for each model were between 979 and 2989 cm(–1), and when selecting the most suitable one in each case, good values of performance parameters were obtained (R2(val) > 0.95 and RPD > 4.0 for TPC; R2(val) > 0.90 and RPD > 3.0 for TA; R2(val) < 0.8 and RPD < 3.0 for CT). Furthermore, also more specific PLS regression models for each phenolic parameter and each grape variety were developed using different regions with results similar to those obtained when dealing with all of the grape varieties. It is concluded that FT-MIR spectroscopy together with multivariate calibration could be a rapid and valuable tool for wineries to carry out the monitoring of phenolic compound extraction during winemaking.

Solanum torvum Swartz. fruit containing phenolic compounds shows antidiabetic and antioxidant effects in streptozotocin induced diabetic rats

In this study, quantification of phenolic compounds and the investigation of antidiabetic and antioxidant activities of the fruit of Solanum torvum Swartz. are described. S. torvum fruit methanol extract (STMe) was administered orally at a dose of 200 and 400mg/kg/day to streptozotocin induced diabetic rats for 30days. The levels of glucose, insulin, total protein, hemoglobin, glycated hemoglobin, liver glycogen and marker enzymes of carbohydrate metabolism, hepatic function and antioxidants were analyzed. High-performance liquid chromatography (HPLC) analysis revealed that STMe contained high levels of phenolic compounds, mainly rutin (1.36%w/w), caffeic acid (12.03%w/w), gallic acid (4.78%w/w) and catechin (0.46%w/w). STMe at 200 and 400mg/kg reduced blood glucose level by 17.04% and 42.10%, respectively in diabetic rats. The levels and/or activities of other biochemical parameters were restored significantly compared to diabetic control rats due to treatment with fruit extract. Histology of liver and pancreas in STMe treated groups substantiated the cytoprotective action of the drug. Immunohistochemical observation of islets in extract treated diabetic rats showed apparent β-cells regeneration. These findings suggest that S. torvum fruit containing phenolic compounds has great potential as a natural source of antidiabetic and antioxidant drug.

Qualitative and Quantitative Evaluation of Phenolic Compounds in Iris dichotoma Pall

The rhizome of Iris dichotoma Pall., a traditional Chinese herbal medicine that contains (iso) flavonoids as the main bioactive compound, has been used to treat several disorders such as inflammation, throat disorders, asthma and coughs. However, there is a lack of suitable methods for its qualitative and quantitative analysis as well as quality control. To establish an HPLC method for the simultaneous determination of phenolic constituents, the identification of characteristic metabolites in the rhizomes of I. dichotoma and to compare their contents in samples from different areas of China. HPLC coupled with diode-array detection (DAD) and electrospray ionisation multistage mass spectrometry (ESI-MS(n) ), and principal component analysis (PCA) were used for the qualitative and quantitative analysis of phenolic compounds in I. dichotoma samples. Twenty characteristic compounds were identified or tentatively characterised. A quantitative HPLC-UV method allowing the simultaneous quantification of 10 phenolic compounds was optimised and validated in terms of linearity, precision, accuracy, and limits of detection and quantification. The methodology developed proved to be effective for the identification and quantification of phenolic compounds in the rhizomes of I. dichotoma. Samples were classified into three groups according to their geographical origin based on their phenolic composition using principal component analysis.

Herbal infusions bioelectrochemical polyphenolic index: Green tea – The gallic acid interference

An amperometric biosensor containing immobilised laccase from Trametes versicolor was used for the quantification of phenolic compounds in herbal infusions and green tea samples, from nine botanical families. The main purpose of this research was to correlate the bioelectrochemical polyphenolic index (BPI) of the samples with the total phenolic content according to the Folin–Ciocalteu spectrophotometric method (TPC), and the total antioxidant activity (TAA) measured by TEAC (Trolox Equivalent Antioxidant Capacity). A strong correlation between BPI, TPC, and TAA was obtained for 10 herbal infusion samples. However, when a green tea sample was taken into account, a decrease in the linear correlation coefficient (r2) from 0.9949 to 0.2599 and 0.5609 to 0.1086 for the relationship between BPI/TPC and BPI/TAA, respectively, was observed. Thus, we could conclude that the green tea’s matrix affects the laccase-based biosensor response. HPLC–DAD analysis showed the presence of gallic acid only in the green tea sample. The results have indicated that gallic acid inhibited the laccase activity regarding the ABTS oxidation in a concentration-dependent manner. The very strong correlation between BPI/TPC obtained for herbal infusions allow us to conclude that the laccase-based biosensor, used in this research, provides a valuable tool to obtain a valid estimation of the classical Folin–Ciocalteu index, in an uncomplicated and fast way.