Capillary electrophoresis fingerprinting and spectrophotometric determination of antioxidant potential for classification of Mentha products

In this work aqueous infusions from ten Mentha herbal samples (four different Mentha species and six hybrids of Mentha x piperita) and 20 different peppermint teas were screened by capillary electrophoresis with UV detection. The fingerprint separation was accomplished in a 25 mM borate background electrolyte with 10% methanol at pH 9.3. The total polyphenolic content in the extracts was determined spectrophotometrically at 765 nm by a Folin–Ciocalteu phenol assay. Total antioxidant activity was determined by scavenging of 2,2-diphenyl-1-picrylhydrazyl radical at 515 nm. The peak areas of 12 dominant peaks from CE analysis, present in all samples, and the value of total polyphenolic content and total antioxidant activity obtained by spectrophotometry was combined into a single data matrix and principal component analysis was applied. The obtained principal component analysis model resulted in distinct clusters of Mentha and peppermint tea samples distinguishing the samples according to their potential protective antioxidant effect. Principal component analysis, using a non-targeted approach with no need for compound identification, was found as a new promising tool for the screening of herbal tea products. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, WeinheimStudent project Grand at Masaryk University [MUNI/A/1500/2015

Comparison of Antioxidant Properties of Different Mentha Piperita Species and Commercial Teas by Capillary Zone Electrophoresis and Spectroscopy

A comparison of antioxidant properties of ten Mentha species and eleven commercially available peppermint teas was performed by electrophoretic fingerprinting of flavonoids and phenolic acids in aqueous infusions and by spectrophotometric determination of total polyphenolic content (TPC) and total antioxidant activity (TAA). Capillary zone electrophoresis with UV detection was used for measurement of fingerprints from the extracts. The antioxidant characteristics were determined by a spectrophotometric method using Folin-Ciocalteu, ABTS radical and DPPH methods. Significant differences were found among various Mentha species and also among different tea brands

Monitoring of HPLC profiles of selected polyphenolic compounds in sea buckthorn (Hippophaë rhamnoides L.) plant parts during annual growth cycle and estimation of their antioxidant potential

Presented work summarizes the data about polyphenolic profiles in various plant parts (leaves, shoots, berries) of sea buckthorn (Hippophaë rhamnoides L.) during the annual growth cycle. A reversed-phase high performance liquid chromatography method (RP-HPLC) coupled with diode-array detection (DAD) was optimized for determination of catechin, epicatechin, gallic acid, p-coumaric acid, caffeic acid, ferulic acid, rutin (quercetin 3-rutinoside) and quercitrin (quercetin 3-rhamnoside). The content of these polyphenolic compounds was monitored in extracts of sea buckthorn plant samples from April to October. The total antioxidant activity was determined using scavenging of 2,2-azino-bis(3-ethylbenzothiazoline-6-sulphonate) cation radical (ABTṠ+) and 1,1-diphenyl-2-picrylhydrazyl radical (DPPḢ). The total content of polyphenols was estimated by conventional spectrophotometric method using Folin-Ciocalteu reagent. The monitoring of temporal changes of selected polyphenolic compounds by RP-HPLC showed that catechin, epicatechin and gallic acid were the most abundant analytes in annual green shoots and leaves, and their content varied significantly during the studied period. © Versita Sp. z o.o

Analysis of organic acids, deacetyl asperulosidic acid and polyphenolic compounds as a potential tool for characterization of noni (Morinda citrifolia) products

Organic acids, deacetyl asperulosidic acid (DAA) and polyphenolic compounds in various noni (Morinda citrifolia L.) products (4 juices, 4 dry fruit powders and 2 capsules with dry fruit powder) were analyzed. Reversed-phase high-performance liquid chromatography (RP-HPLC) coupled with a variable wavelength detector (VWD) and electrospray ionization time-of-flight mass spectrometer (ESI-TOF MS) was applied for simultaneous analysis of organic acids (malic, lactic, citric and succinic acid) and DAA. An RP-HPLC method with diode-array detector (DAD) was developed for the analysis of polyphenolic compound content (rutin, catechin, quercitrin, kaempferol, gallic acid, caffeic acid and p-coumaric acid). The developed methods can contribute to better characterization of available noni products that is required from the consumers. In our study, we discovered significant dissimilarities in the content of DAA, citric acid and several phenolic compounds in some samples