scholarly journals Determination of the polyphenol contents in Macedonian grapes and wines by standardized spectrophotometric methods

2010 ◽  
Vol 75 (1) ◽  
pp. 45-59 ◽  
Author(s):  
Violeta Ivanova ◽  
Marina Stefova ◽  
Fabio Chinnici
Keyword(s):  
Extraction Efficiency ◽  
Total Phenolics ◽  
Principal Component ◽  
White Wine ◽  
Total Flavonoids ◽  
Spectrophotometric Methods ◽  
Acetone Water ◽  
Total Anthocyanins ◽  
Grape Varieties

Wines and grapes contain a large array of phenolic compounds belonging to non-flavonoids and flavonoids. This study evaluates the polyphenolic contents of six commercial red and white Macedonian wines and four grape varieties. Spectrophotometric methods were applied for the determination of the total phenolics, the total flavonoids, the total anthocyanins and the total catechins. The efficiency of acetone/water (80/20) and methanol/water (80/20) solutions for the extraction of polyphenols from grape pulp, seeds and skins were compared. The best extraction efficiency was achieved using acetone/ water. The obtained results showed that Macedonian grapes are rich in polyphenols, whereby the highest concentration of total phenolics was found for Vranec grapes. The analyzed wines contained high contents of polyphenol; the highest contents were found for Disan wine produced from the Vranec variety of grapes (1515 mg/L total phenolics, 1103 mg/L total flavonoids, 237 mg/L total anthocyanins and 845 mg/L total catechins). Principal component analysis was employed to check possible groupings of the studied red and white wine samples. A clear separation of white wines from red ones was observed.

scholarly journals Comparison of different extraction solvents for assay of the polyphenol content in the peel and pulp of 21 apple cultivars from Macedonia

2016 ◽  
Vol 35 (1) ◽  
pp. 29 ◽  
Author(s):  
Ana Petkovska ◽  
Viktor Gjamovski ◽  
Marina Stefova
Keyword(s):  
Extraction Efficiency ◽  
Spectrophotometric Methods ◽  
Acetone Water ◽  
Freeze Dried ◽  
Apple Peel ◽  
Total Anthocyanins ◽  
Apple Cultivars ◽  
Extraction Solvents ◽  
The Republic

Apples (Malus domestica Borkh.) contain a large array of phenolic compounds belonging to flavonoids and non-flavonoids. This study systematically evaluates the polyphenolic content of 21 apple cultivars from the Republic of Macedonia, both commercial and autochthonous, applying spectrophotometric methods for the determination of total polyphenolic compounds, total flavonoids, total anthocyanins and total flavan-3-ols. The reliability of these methods was checked by confirming the method linearity and accuracy with standards and spiked samples. The efficiency of acetone, water, methanol and a mixture of methanol/water (90 : 10, V/V) as extraction solvents was compared. Evident differences between extracts obtained from freeze-dried apple peel and pulp, extracted with different solvents, and analyzed with the four spectrophotometric tests, were observed and discussed. The most satisfactory extraction efficiency was achieved using methanol/water (90 : 10, V/V) mixture. The results obtained from the methanol/water extracts illustrate evident differences between polyphenol contents and reveal the diversity in polyphenols, total flavonoid and flavanol composition between the assayed commercial and autochthonous cultivars. The maximum abundance of polyphenols was noticed in the peel of Tetovka and Livadarka cultivars (15.63 mg/g GAE and 14.85 mg/g GAE, respectively) and in the pulp of Pasalma, Tetovka and Livadarka cultivars (12.55 mg/g GAE, 11.45 mg/g GAE and 11.22 mg/g GAE, respectively).

scholarly journals Evaluation of phenolic compounds and antioxidant activity in some edible flowers

2020 ◽  
Vol 5 (1) ◽  
pp. 857-870
Author(s):  
Fernando Gonçalves ◽  
João Carlos Gonçalves ◽  
Ana Cristina Ferrão ◽  
Paula Correia ◽  
Raquel P. F. Guiné
Keyword(s):  
Antioxidant Activity ◽  
Total Phenolics ◽  
Total Phenolic ◽  
Potential Health ◽  
Phenolic Contents ◽  
Spectrophotometric Methods ◽  
Potential Source ◽  
Successive Extraction ◽  
Dpph Method ◽  
Total Anthocyanins

AbstractRecently, edible flowers (EF) have aroused increased interest because of their aesthetic properties as well as potential health benefits related to the occurrence of some bioactive compounds. Therefore, the aim of this work was to evaluate the total phenolics, anthocyanins, flavonoids, and antioxidant activity (AOA) (following DPPH and ABTS methods) in eleven EF. The samples were subjected to three successive extraction steps using methanol, and these extracts were then analysed for the aforementioned properties using spectrophotometric methods. The obtained extracts were used for the quantification of phenolic composition and AOA. The results indicated that, among the flowers analysed in this study, red rose, pink rose, and red carnation possessed the highest total phenolic contents (27.53, 23.30, and 18.17 mg g−1 gallic acid equivalents, respectively), total anthocyanins (3.07, 1.97, and 4.47 mg g−1 catechin equivalents [CE], respectively), and AOA (12.07, 15.77, and 12.93 mg g−1 TE, respectively, as given by the DPPH method or 8.23, 9.27 and 8.00 mg g−1 TE, respectively, as given by the ABTS method). The flowers with highest flavonoids contents were red carnation, Mexican marigold, and pink rose (17.50, 16.90, and 16.57 mg g−1 CE, respectively). Cluster analysis grouped the analysed flowers into two groups, those richest in phenolics with AOA and those not so rich. Finally, some important correlations were observed between the total phenolics and the AOA. In conclusion, these flowers could represent a potential source of natural compounds with antioxidant capacity.

Development and Validation of Chemometric-Assisted Spectrophotometric Methods for Simultaneous Determination of Phenylephrine Hydrochloride and Ketorolac Tromethamine in Binary Combinations

2016 ◽  
Vol 99 (5) ◽  
pp. 1247-1251 ◽  
Author(s):  
Hamed M Elfatatry ◽  
Mokhtar M Mabrouk ◽  
Sherin F Hammad ◽  
Fotouh R Mansour ◽  
Amira H Kamal ◽  
...  
Keyword(s):  
Least Squares ◽  
Simultaneous Determination ◽  
Principal Component Regression ◽  
Principal Component ◽  
Data Matrix ◽  
Ketorolac Tromethamine ◽  
Concentration Data ◽  
Phenylephrine Hydrochloride ◽  
Spectrophotometric Methods

Abstract The present work describes new spectrophotometric methods for the simultaneous determination of phenylephrine hydrochloride and ketorolac tromethamine in their synthetic mixtures. The applied chemometric techniques are multivariate methods including classical least squares, principal component regression, and partial least squares. In these techniques, the concentration data matrix was prepared by using the synthetic mixtures containing these drugs dissolved in distilled water. The absorbance data matrix corresponding to the concentration data was obtained by measuring the absorbances at 16 wavelengths in the range 244–274 nm at 2 nm intervals in the zero-order spectra. The spectrophotometric procedures do not require any separation steps. The accuracy, precision, and linearity ranges of the methods have been determined, and analyzing synthetic mixtures containing the studied drugs has validated them. The developed methods were successfully applied to the synthetic mixtures and the results were compared to those obtained by a reported HPLC method.

scholarly journals Liquid Chromatographic and Spectrophotometric Determination of Diflucortolone Valerate and Isoconazole Nitrate in Creams

2011 ◽  
Vol 94 (1) ◽  
pp. 128-135 ◽  
Author(s):  
Elif Karacan ◽  
Mehmet Gokhan Çaġlayan ◽  
İsmail Murat Palabiyik ◽  
Feyyaz Onur
Keyword(s):  
Principal Component Regression ◽  
Principal Component ◽  
Derivative Spectrophotometry ◽  
Data Matrix ◽  
Concentration Data ◽  
Spectrophotometric Methods ◽  
First Derivative ◽  
First Derivative Spectrophotometry ◽  
Liquid Chromatographic

Abstract A new RP-LC method and two new spectrophotometric methods, principal component regression (PCR) and first derivative spectrophotometry, are proposed for simultaneous determination of diflucortolone valerate (DIF) and isoconazole nitrate (ISO) in cream formulations. An isocratic system consisting of an ACE® C18 column and a mobile phase composed of methanol–water (95+5, v/v) was used for the optimal chromatographic separation. In PCR, the concentration data matrix was prepared by using synthetic mixtures containing these drugs in methanol–water (3+1, v/v). The absorbance data matrix corresponding to the concentration data matrix was obtained by measuring the absorbances at 29 wavelengths in the range of 242–298 nm for DIF and ISO in the zero-order spectra of their combinations. In first derivative spectrophotometry, dA/dλ values were measured at 247.8 nm for DIF and at 240.2 nm for ISO in first derivative spectra of the solution of DIF and ISO in methanol–water (3+1, v/v). The linear ranges were 4.00–48.0 μg/mL for DIF and 50.0–400 μg/mL for ISO in the LC method, and 2.40–40.0 μg/mL for DIF and 60.0–260 μg/mL for ISO in the PCR and first derivative spectrophotometric methods. These methods were validated by analyzing synthetic mixtures. These three methods were successfully applied to two pharmaceutical cream preparations.

Anthocyanins profile, total phenolics and antioxidant activity of two Romanian red grape varieties: Feteascǎ neagrǎ and Bǎbeascǎ neagrǎ (Vitis vinifera)

2015 ◽  
Vol 69 (12) ◽  
Author(s):  
Oana Emilia Constantin ◽  
Mihaela Skrt ◽  
Natasa Poklar Ulrih ◽  
Gabriela Râpeanu
Keyword(s):  
Antioxidant Activity ◽  
Vitis Vinifera ◽  
High Performance ◽  
Total Phenolics ◽  
High Performance Liquid Chromatographic ◽  
Phenolic Composition ◽  
Total Anthocyanins ◽  
Red Grape ◽  
Grape Varieties ◽  
Liquid Chromatographic

AbstractThe phenolic composition of Fetească neagră and Băbească neagră grapes from Dealul Bujorului vineyard (south-east Romania) was studied using the spectrophotometric and high-performance liquid chromatographic (HPLC) methods. The results revealed significant differences between these cultivars. Total anthocyanins ranged from 0.22-5.98 mg g

scholarly journals Evaluation of the antioxidant activity of some types of red and white wines

2014 ◽  
Vol 25 (2) ◽  
pp. 65-70 ◽  
Author(s):  
Ana Leahu ◽  
Sonia Amariei ◽  
Cristina Damian ◽  
Mircea Oroian ◽  
Sorina Ropciuc
Keyword(s):  
Antioxidant Activity ◽  
Multivariate Data Analysis ◽  
Red Wine ◽  
Total Phenolics ◽  
Principal Component ◽  
White Wine ◽  
Total Phenols ◽  
Polyphenol Content ◽  
Total Polyphenol ◽  
White Wines

Abstract Samples of commercially available Romanian wines were analyzed in order to determine total phenols content and the antioxidant activity. The content of total phenolics in the extracts was determined according to the Folin-Ciocalteu method and calculated as gallic acid equivalents (mg GAE/100g). Antiradical activities of the extracts were evaluated by a micro assay using 1, 1¢-diphenyl-2-picrylhydrazyl spectrophotometric method. Wine characteristics measurements were examined by multivariate data analysis, using principal component analysis (PCA). Total polyphenol content was correlated to the antioxidant activity of the studied wine samples. The values of the inhibition power of free radical, PI%, are ranging between 1.68 for white wine and 0.95 for red wine (“Bull blood” bottled by Tohani winery, Prahova, Romania).

scholarly journals NUTRITIONAL EVALUATION OF HERBACEOUS PEONY (PAEONIA LACTIFLORA PALL.) PETALS

2017 ◽  
pp. 518 ◽  
Author(s):  
Li Weixing ◽  
Yang Shunbo ◽  
Cui Hui ◽  
Hua Yanmin ◽  
Tao Jun ◽  
...  
Keyword(s):  
Organic Acid ◽  
Evaluation System ◽  
Total Phenolics ◽  
Sugar Content ◽  
Soluble Sugar ◽  
Principal Component ◽  
Total Flavonoids ◽  
Paeonia Lactiflora ◽  
Sod Activity ◽  
Herbaceous Peony

Herbaceous peony (Paeonia lactiflora Pall.) is a kind of plant with ornamental, edible and medicinal values, and few studies were concerned to edible aspect of herbaceous peony petals. The aim of this research is to establish edible quality evaluation system of herbaceous peony flowers. Petals of 46 P. lactiflora cultivars at full bloom period were used to determine the content of soluble sugar, organic acid, protein, Vc (Vitamin C), total phenolics, total flavonoids, mineral elements and SOD (superoxide dismutase) activity and screen out evaluation index for edible herbaceous peony. The results showed that flower petals of herbaceous peony contained lots of nutrients and the contents varied with different cultivars. The soluble sugar content was 66.55-177.28 mg/g FW, organic acid 2.19-6.90 mg/g FW, soluble protein 6.53-121.56 mg/g FW, Vc 9.77-30.24 mg/100 g FW, total phenolics 9.41-33.01 mg/g DW, total flavonoids 3.50-17.56 mg/g DW, SOD activity 305.62-520.42 U/g FW, total amino acids 6.43-11.99 g/100 g DW. The average content of Na, Mg, K, Ca, Mn, Fe, Ni, Zn, Mo, Cr were 55.88±14.90 µg/g DW, 1218.22±349.60 µg/g DW, 11252.23±2477.54 µg/g DW, 1975.40±706.58 µg/g DW, 8.30±6.55 µg/g DW, 103.56±182.72 µg/g DW, 10.73±37.94 µg/g DW, 22.80±16.68 µg/g DW, 1.84±5.89 µg/g DW and 17.36±44.89 µg/g DW, respectively. Based on principal component analysis and cluster analysis, we found ‘Dielian Qihua’, ‘Zhushapan’, ‘Xueyuan Honghua’, ‘Wulong Jisheng’, ‘Honglou’, ‘Bingshan’, ‘Hongyan Yushuang’, ‘Zituo Ronghua’, ‘Zifengyu’, ‘Fenlou Dianchun’ had better edible quality. The results will provide some information for the comprehensive utilization of herbaceous peony petals and the breeding of edible herbaceous peony cultivars.

scholarly journals Influence of steeping time on biological activity of black mulberry leaves tea

2016 ◽  
pp. 177-191 ◽  
Author(s):  
Sladjana Cestic ◽  
Marija Radojkovic ◽  
Aleksandra Cvetanovic ◽  
Pavle Maskovic ◽  
Sasa Djurovic
Keyword(s):  
Total Phenolics ◽  
Reducing Power ◽  
Total Flavonoids ◽  
Mulberry Leaves ◽  
Tea Quality ◽  
Total Flavonoids Content ◽  
Phenolics Content ◽  
Polyphenolic Profile ◽  
Boiled Water

Black mulberry leaves teas (BMLTs) were prepared using boiled water and different steeping time (5 10, 20, 35 and 45 minutes). In order to establish the connection between steeping time and tea quality, total phenolics content (TPC), total flavonoids content TFC contents were measured, as well as two antioxidant assays (DPPH and reducing power assays), alone with antimicrobial and cytotoxic tests. The obtained results showed that TPC, TFC, IC50 and EC50 values increased with the increase in steeping time, while antimicrobial and cytotoxic activity exhibited different tendency. Based on the obtained results, the 10-minute steeping time was the optimum for tea preparation and this tea was used for the determination of polyphenolic profile using HPLC-MS technique. The results showed that the main compounds in BMLT were chlorogenic and caffeic acids with the contents of 7226.00 and 537.52 ?g/g, respectively.

scholarly journals Multivariate Validated Models for Simultaneous Determination of Ibuprofen and Famotidine in the Presence of Related Substances

2018 ◽  
Vol 101 (4) ◽  
pp. 1001-1007
Author(s):  
Eman S Elzanfaly ◽  
Hala E Zaazaa ◽  
Aya T Soudi ◽  
Maissa Y Salem
Keyword(s):  
Simultaneous Determination ◽  
Multivariate Calibration ◽  
Degradation Products ◽  
Principal Component Regression ◽  
Principal Component ◽  
Standard Addition ◽  
Spectrophotometric Methods ◽  
Related Substances ◽  
Calibration Methods

Abstract Two multivariate validated spectrophotometric methods, namely partial least-squares (PLS) and principal component regression (PCR), were developed and validated for the determination of ibuprofen and famotidine in presence of famotidine degradation products and ibuprofen impurity (4-isobutylacetophenone). A calibration set was prepared in which the two drugs together with the degradation products and impurity were modeled using a multilevel multifactor design. This calibration set was used to build the PLS and PCR models. The proposed models successfully predicted the concentrations of both drugs in validation samples, with low root mean square error of cross validation (RMSECV) percentage. The method was validated by the estimate of the figures of merit depending on the net analyte signal. The results of the two models showed that the simultaneous determination of both drugs could be performed in the concentration ranges of 100–500 µg/mL for ibuprofen and 5–25 µg/mL for famotidine. The proposed multivariate calibration methods were applied for the determination of ibuprofen and famotidine in their pharmaceutical formulation, and the results were verified by the standard addition technique.

scholarly journals Simultaneous Spectrophotometric Determination of Elbasvir and Grazoprevir in a Pharmaceutical Preparation

2018 ◽  
Vol 101 (2) ◽  
pp. 394-400 ◽  
Author(s):  
Khalid A M Attia ◽  
Nasr M El-Abasawi ◽  
Ahmed El-Olemy ◽  
Ahmed H Abdelazim
Keyword(s):  
Pharmaceutical Preparation ◽  
Principal Component Regression ◽  
Predictive Ability ◽  
Principal Component ◽  
Spectra Analysis ◽  
Pharmaceutical Dosage Form ◽  
Manufacturing Method ◽  
Spectrophotometric Methods ◽  
Significant Difference

Abstract Three UV spectrophotometric methods have been developed for the simultaneous determination of two new Food and Drug Administration-approved drugs, elbasvir (EBV) and grazoprevir (GRV), in their combined pharmaceutical dosage form. These methods include dual wavelength (DW), classic least-squares (CLS), and principal component regression (PCR). To achieve the DW method, two wavelengths were chosen for each drug in a way to ensure the difference in absorbance was zero from one drug to the other. GRV revealed equal absorbance at 351 and 315 nm, for which the distinctions in absorbance were measured for the determination of EBV. In the same way, distinctions in absorbance at 375 and 334.5 nm were measured for the determination of GRV. Alternatively, the CLS and PCR models were applied to the spectra analysis because the synchronous inclusion of many unreal wavelengths rather than using a single wavelength greatly increased the precision and predictive ability of the methods. The proposed methods were successfully applied to the assay of these drugs in their pharmaceutical formulation. The obtained results were statistically compared with manufacturing methods. The results conclude that there was no significant difference between the proposed methods and the manufacturing method with respect to accuracy and precision.

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