scholarly journals Capillary electrophoresis-UV analysis using silica-layer coated capillary for separation of seven phenolic acids and caffeine and its application to tea analysis

2021 ◽  
Vol 3 (12) ◽  
Author(s):  
Pattamaporn Hemwech ◽  
Apinya Obma ◽  
Sasinun Detsangiamsak ◽  
Supa Wirasate ◽  
Pimchai Chaiyen ◽  
...  

Abstract This work presents an innovative silica-layer coated capillary with comparison study of the silica-layer coated capillary and the fused-silica capillary for the separation of seven phenolic acids viz. p-hydroxyphenylacetic acid (PHPA), p-coumaric acid (PCA), p-hydroxybenzoic acid (PHBA), caffeic acid (CFA), (3,4-dihydroxyphenyl)acetic acid (DHPA), gallic acid (GLA), and 2,3,4-trihydroxybenzoic acid (THBA), together with caffeine (CF), by capillary electro-chromatography (CEC) and micellar electrokinetic chromatography (MEKC), respectively. The running buffer was 25.0 mM borate at pH 9.0, with addition of 50.0 mM sodium dodecyl sulfate for the MEKC mode. The non-coated capillary could not separate all seven phenolic acids by CEC or MEKC. This was achieved using the coated capillary for both CEC and MEKC. The innovative coated capillary with CEC had plate number N ≥ 2.0 × 104 m−1 and resolution Rs ≥ 1.6 for all adjacent pairs of peaks. The capillary was also able to separate GLA and THBA which are structural isomers. Although MEKC mode provided comparable efficiency and selectivity, the reduced EOF of the coated capillary led to longer separation time. The linear calibration range of the seven phenolic acids and caffeine were different but the coefficients of determinations (r2) were all > 0.9965. The precisions of the relative migration times and peak area ratios of analyte to internal standard were 0.1–1.8% and 1.8–6.8%, respectively. There were no statistical differences in the efficiency of separation of the phenolic acids and caffeine for three coated capillaries. It was applied to the analysis of caffeine and phenolic acids in brewed tea using tyramine as the internal standard. The tea samples were diluted prior to analysis by CEC. The separation was less than 15 min. Caffeine, gallic acid and p-coumaric acid were detected and quantified. Caffeine and gallic acid contents were 10.8–15.0 and 2.6–4.8 mg g−1 dry tea leaves, respectively. p-Coumaric acid was detected in only one of the samples with a content of 0.4 mg g−1. Percent recoveries of spiked diluted samples were 90 ± 9 to 106 ± 13%, respectively. Article highlights Silica-layer coated capillary is first reported for simultaneous separation of seven phenolic acids by non-MEKC analysis. Performance between coated, and non-coated capillaries with analysis by CEC and MEKC were compared. Plate number, resolution, capillary reproducibility, and electroosmotic flow mobility are investigated. Graphical abstract

2017 ◽  
Vol 44 (No. 4) ◽  
pp. 178-185 ◽  
Author(s):  
Alina Kałużewicz ◽  
Jolanta Lisiecka ◽  
Monika Gąsecka ◽  
Włodzimierz Krzesiński ◽  
Tomasz Spiżewski ◽  
...  

This study was conducted to study the influence of plant density and irrigation on the content of phenolic compounds, i.e., phenolic acids and flavonols in cv. ‘Sevilla’ cauliflower curds. Levels of phenolic acids and flavonols were in the range of 3.0–6.2 mg and 25.4–87.8 mg/100 g of dry weight, respectively, depending on plant density and irrigation. Of the phenolic acids, caffeic acid was detected in the highest amount, followed by p-coumaric acid, sinapic acid, gallic acid, and ferulic acid. Of the two flavonols detected, the levels of quercetin were higher than those of kaempferol. The content of the detected phenolic acids (with the exception of ferulic acid) and both flavonols increased with increasing plant density. Furthermore, the concentration of phenolic compounds (with the exception of ferulic acid) was significantly higher under irrigation.


2020 ◽  
Author(s):  
Prince A Fordjour ◽  
Jonathan P Adjimani ◽  
Bright Asare ◽  
Nancy O Duah-Quashie ◽  
Neils B Quashie

Abstract Background In the absence of an effective vaccine against malaria, chemotherapy remains a major option in the control of the disease. Then, the recent report of the emergence and spread of clones of Plasmodium falciparum resistant to available antimalarial drugs should be of concern as it poses a threat to disease control. Compounds whose pharmacological properties have been determined and touted for other disease can be investigated for antimalarial activity. Phenolic acids (polyphenols) have been reported to exhibit antioxidant, anticancer, anti-inflammatory, antiviral and antibiotic effects. However, information on their antimalarial activity is scanty. Phenolic acids are present in a variety of plant-based foods: mostly high in the skins and seeds of fruits as well as the leaves of vegetables. Systematic assessment of these compounds for antimalarial activity is therefore needed. Method Using the classical in vitro drug test, the antimalarial activities of five hydroxycinnamic acids, (caffeic acid, rosmarinic acid, chlorogenic acid, o-Coumaric acid and ferulic acid) and two hydroxybenzoic acids (gallic acid and protocatechuic acid) against 3D7 clones of Plasmodium falciparum was determined. Results Among the phenolic acids tested, caffeic acid and gallic acid were found to be the most effective, with mean IC 50 value of 17.73µg/ml and 26.59µg/ml respectively for three independent determinations. Protocatechuic acid had an IC 50 value of 30.08 µg/ml. Rosmarinic acid and chlorogenic acid, showed moderate antimalarial activities with IC 50 values of 103.59µg/ml and 105µg/ml respectively. The IC 50 values determined for ferulic acid and o-Coumaric acid were 93.36µg/ml and 82.23µg/ml respectively. Conclusion The outcome of this study suggest that natural occurring phenolic compounds have appreciable level of antimalarial activity which can be exploited for use through combination of actions/efforts including structural manipulation to attain an increase in their antimalarial effect. Eating of natural food products rich in these compounds could provide antimalarial prophylactic effect.


2009 ◽  
Vol 134 (5) ◽  
pp. 491-496 ◽  
Author(s):  
Valentina Schmitzer ◽  
Robert Veberic ◽  
Gregor Osterc ◽  
Franci Stampar

The concentration of major anthocyanins, quercetins, catechin, and phenolic acids during flower development of Rosa ×hybrida L. ‘KORcrisett’ was quantified using high-performance liquid chromatography/mass spectrometry. Additionally, the changes in petal color were monitored colorimetrically at four different stages of development (bud, partially open flowers, fully open flowers, senescent flowers) and correlation was calculated between the chromaticity parameters and major/total anthocyanins. Color parameters a*, b*, and h° decreased with the progression of flower development and a*/b* ratio and lightness (L*) increased. In rose petals, a negative trend in the content of major (pelargonidin-3,5-di-O-glucoside, cyanidin-3,5-di-O-glucoside) and minor (pelargonidin-3-O-glucoside, cyanidin-3-O-glucoside, peonidin-3-O-glucoside) anthocyanins was observed during flower development. Buds contained almost threefold higher concentrations of pelargonidin-3,5-di-O-glucoside and fourfold higher concentrations of cyanidin-3,5-di-O-glucoside than senescent flowers. Buds also contained significantly more quercetins (quercetin-3-O-rutinoside, quercetin-3-O-glucoside, and quercetin-3-O-rhamnoside), catechin, and phenolic acids (gallic acid, protocatechulic acid, chlorogenic acid, caffeic acid, p-coumaric acid) than flowers of subsequent developmental stages. The most significant differences were observed in the content of gallic acid; buds contained almost sixfold higher values than senescent flowers. Correlation analysis revealed a strong correlation between chromaticity parameters a*, b*, a*/b* ratio, h°, L*, and major/total anthocyanins with values ranging from 0.60 to –0.84.


2016 ◽  
Vol 5 (06) ◽  
pp. 4641 ◽  
Author(s):  
Adel Abdel Moneim* ◽  
Sanaa M. Abd El-Twab ◽  
Mohamed B. Ashour ◽  
Ahmed I. Yousef

The goal of diabetes treatment is primarily to save life and alleviate symptoms and secondary to prevent long-term diabetic complications resulting from hyperglycemia. Thus, our present investigation was designed to evaluate the hepato-renal protective effects of gallic acid and p-coumaric acid in nicotinamide/streptozotocin (NA/STZ)-induced diabetic rats. Experimental type 2 diabetes was induced by a single intraperitoneal (i.p.) injection of STZ (65 mg/kg b.wt.), after 15 min of i.p. injection of NA (120 mg/kg b.wt.). Gallic acid and p-coumaric acid were orally administered to diabetic rats at a dose of 20, 40 mg/kg b.wt./day, respectively, for 6 weeks. Body weight, serum glucose, protein profile, liver function enzymes and kidney function indicators was assayed. Treatment with either gallic acid or p-coumaric acid significantly ameliorated the elevated levels of glucose, alanine aminotransferase (ALT), aspartate aminotransferase (AST), urea and uric acid. Both compounds were also found to restore total protein, albumin, and globulin as well as body weight of diabetic rats to near normal values. It can conclude that both gallic acid and p-coumaric acid have potent hypoglycemic and hepato-renal protective effects in diabetic rats. Therefore, our results suggest promising hypoglycemic agents that can attenuate the progression of diabetic hepatopathy and nephropathy.


1959 ◽  
Vol 37 (1) ◽  
pp. 537-547 ◽  
Author(s):  
D. R. McCalla ◽  
A. C. Neish

p-Coumaric, caffeic, ferulic, and sinapic acids were found to occur in Salvia splendens Sello in alkali-labile compounds of unknown constitution. A number of C14-labelled compounds were administered to leafy cuttings of salvia and these phenolic acids were isolated after a metabolic period of several hours and their specific activities measured. Cinnamic acid, dihydrocinnamic acid, L-phenylalanine, and (−)-phenyllactic acid were found to be good precursors of the phenolic acids. D-Phenylalanine, L-tyrosine, and (+)-phenyllactic acid were poor precursors. A kinetic study of the formation of the phenolic acids from L-phenylalanine-C14 gave data consistent with the view that p-coumaric acid → caffeic acid → ferulic acid → sinapic acid, and that these compounds can act as intermediates in lignification. Feeding of C14-labelled members of this series showed that salvia could convert any one to a more complex member of the series but not so readily to a simpler member. Caffeic acid-β-C14 was obtained from salvia after the feeding of L-phenylalanine-β-C14 or cinnamic acid-β-C14, and caffeic acid labelled only in the ring was obtained after feeding generally labelled shikimic acid.


2014 ◽  
Vol 97 (1) ◽  
pp. 114-120 ◽  
Author(s):  
Vítor Todeschini ◽  
Maximiliano da Silva Sangoi ◽  
Alianise da Silva Meira ◽  
Diogo Miron ◽  
Alini Dall Cortivo Lange ◽  
...  

Abstract A stability-indicating micellar electrokineticchromatography (MEKC) method was developed and validated for simultaneous analysis of delapril (DEL) and manidipine (MAN) using salicylic acid as an internal standard. The MEKC method was performed using a fused-silica capillary (effective length of 72 cm) with 50 mM of borate buffer and 5 mM of anionic surfactant sodium dodecylsulfate at pH9.0 as the background electrolyte. The separationwas achieved at 25 kV applied voltage and 35°C. The injection was performed at 50 mbar for5s, with detection at 208 nm. The method was linear in the range of 15–150 μg/mL (r2 = 0.9966) for DEL and 5–50 μg/mL (r2 = 0.9985) for MAN with adequate results for the precision (≤1.87%) and accuracy (98.94% for DEL and 100.65% for MAN). The specificity of the method and its stability-indicating capability was demonstrated through forced degradation studies, which showed that there was no interference from the excipients. The Plackett-Burman experimental design was used for robustness evaluation, giving results within the acceptable range. The method was successfully applied for analysis of the drugs, and the results were compared to an LC method, resulting in nonsignificant differences (P = 0.78 and0.84 for DEL and MAN, respectively).


Plants ◽  
2020 ◽  
Vol 9 (7) ◽  
pp. 908 ◽  
Author(s):  
Hosam O. Elansary ◽  
Agnieszka Szopa ◽  
Paweł Kubica ◽  
Halina Ekiert ◽  
Fahed A. Al-Mana ◽  
...  

Acacia saligna and Lawsonia inermis natural populations growing in Northern Saudi Arabia might be a valuable source of polyphenols with potent biological activities. Using high-performance liquid chromatography–diode array detection (HPLC-DAD), several polyphenols were detected tentatively in considerable amounts in the methanolic leaf extracts of A. saligna and L. inermis. A. saligna mainly contained rutoside, hyperoside, quercetin 3-glucuronide, gallic acid and p-coumaric acid, whereas those of L. inermis contained apigenin 5-glucoside, apigetrin and gallic acid. Strong antioxidant activities were found in the leaf extracts of both species due to the presence of hyperoside, quercetin 3-glucuronide, gallic acid, isoquercetin, p-coumaric acid, quercitrin and rutoside. A. saligna and L. inermis leaf extracts as well as hyperoside, apigenin 5-glucoside, and quercetin 3-glucuronide significantly reduced reactive oxygen species accumulation in all investigated cancer cells compared to the control. Methanolic leaf extracts and identified polyphenols showed antiproliferative and cytotoxic activities against cancer cells, which may be attributed to necrotic cell accumulation during apoptotic periods. Antibacterial activities were also found in both species leaf extracts and were twice as high in A. saligna than L. inermis due to the high composition of rutoside and other polyphenols. Finally, strong antifungal activities were detected, which were associated with specific phenols such as rutoside, hyperoside, apigenin 5-glucoside and p-coumaric acid. This is the first study exploring the polyphenolic composition of A. saligna and L. inermis natural populations in northern Saudi Arabia and aiming at the detection of their biological activities.


2011 ◽  
Vol 94 (1) ◽  
pp. 9-16 ◽  
Author(s):  
Anna Bogucka-Kocka ◽  
Katarzyna Szewczyk ◽  
Magdalena Janyszek ◽  
Sławomir Janyszek ◽  
Łukasz Cieśla

Abstract Eighteen species belonging to the Carex genus were checked for the presence and the amount of eight phenolic acids (p-hydroxybenzoic, vanillic, caffeic, syringic, protocatechuic, p-coumaric, sinapic, and ferulic) by means of HPLC. Both the free and bonded phenolic acids were analyzed. The majority of the analyzed acids occurred in the studied species in relatively high amounts. The highest concentrations found were caffeic acid and p-coumaric acid, for which the detected levels were negatively correlated. A very interesting feature was the occurrence of sinapic acid, a compound very rarely detected in plant tissues. Its distribution across the analyzed set of species can be hypothetically connected with the humidity of plants' habitats. Several attempted tests of aggregative cluster analysis showed no similarity to the real taxonomical structure of the genus Carex. Thus, the phenolic acids' composition cannot be considered as the major taxonomical feature for the genus Carex.


1985 ◽  
Vol 68 (3) ◽  
pp. 592-595
Author(s):  
Peter D Bland

Abstract A method is described for the determination of cypermethrin, 3-(2,2- dichloroethenyl)-2,2-dimethyl-cyclopropanecarboxylate cyano-(3- phenoxyphenyl)methyl ester, in technical and formulated material by capillary gas chromatography (CGC). Samples of technical or formulated material are dissolved in CH2Cl2 containing dicyclohexyl phthalate as internal standard. The solution is injected into a gas chromatograph fitted with a flame ionization detector and capillary column of 25 m x 0.32 mm fused silica with a thick film OV-1 phase at 240°C. Injection is made into a heated injection port fitted with an antidiscrimination device in a split mode. Peak areas obtained at retention times of the internal standard and active ingredient are measured with an integrator. The quantity of cypermethrin is determined by comparing the internal standard and active ingredient peak areas with those obtained from a calibration solution containing known amounts of internal standard and pure active ingredient. Five samples were chosen for collaborative study: technical cypermethrin, 70% liquid concentrate, 3 lb/US gal. emulsifiable, 3 ib/US gal. oil concentrate, and 40% wettable powder. Twelve collaborators carried out replicate determinations on each sample on separate days. Coefficients of variation between laboratories (CVX) were 2.13 for the technical, 2.94 for the emulsifiable concentrate, 3.51 for the liquid concentrate, 2.66 for the wettable powder, and 2.29 for the oil concentrate. The method was adopted official first action.


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