Study of the Antioxidant Property Variation of Cornelian Cherry Fruits during Storage Using HPTLC and Spectrophotometric Assays

Cornus species fruits are well known as a rich source of antioxidant compounds responsible for their diverse health benefits. The present study aims to investigate the variation of the total antioxidant capacity of Cornelian cherry (Cornus mas L.) fruits during storage, using high-performance thin-layer chromatography (HPTLC) and two spectrophotometric assays based on different mechanisms: the 2,2-azinobis(3-ethylbenzothiazolyne-6-sulphonic acid) radical cation (ABTS+∙) assay and the ferric reducing antioxidant power (FRAP) assay. The fruit extract was stored at room temperature (22°C) for 19 days. No major differences in the total antioxidant capacity were observed during this period, indicating that storage does not have any deleterious effect on the antioxidant properties of the investigated fruits extract. The antioxidant capacity varied between 12.91 and 12.83 µmol Trolox/g fruit as determined by the HPTLC method and from 36.13 to 33.93 µmol Trolox/g fruit as determined by the ABTS assay

Influence of Intermittent Heating during Maceration on the Antioxidant Capacity of Some Grape Seeds and Skins

Ethanolic extracts from seeds and skins of three red grape varieties, namely, 'Cabernet Sauvignon', 'Merlot' and 'Burgund' from a Romanian winery, were prepared by maceration using different temperature conditions. The stable free radicals DPPH (2, 2-diphenyl- 1-picrylhydrazyl) and Tempol (4-hydroxy-2,2,6,6-tetramethylpiperidin-N-oxyl) were used in order to evaluate the antioxidant capacity of the extracts. The variation in time of free radical concentration was followed by double integration of the EPR spectra of the samples obtained after maceration under different conditions (room temperature and intermittent heating). Results showed that the antioxidant capacity depends on the nature of analysed samples (either being seeds or skins) and grape variety. The results also show that the intermittent heating during maceration leads to a decrease of the antioxidant capacity of samples

Student Portrait, Westbrook Seminary and Junior College, 1930-34

Early 1930s Westbrook Seminary and Junior College individual student photographic portrait by Wilson Photo, Cambridge, Mass. In pencil on the back is written: C. Foss ?https://dune.une.edu/wchc_photos_students1930s/1003/thumbnail.jp

Evaluation of the pro-oxidant activity of the studied extract.

<p>The oxyHb (25 μM) is readily oxidized into met form in the presence of the extract (0.2 μg/mL final concentration) and laccase (100 nM) (<b>A</b>). Comparison between the prooxidant reactivity of the identified components of the extract all at the same molar concentration (5 μM) (<b>B</b>), their mixture in same ratios as in the extract prior hydrolysis (standard mixture 1) and after hydrolysis (standard mixture 2) and of the two analysed extracts (<b>C</b>). The comparison of the kinetic profile of the oxyHb oxidation in the presence of the two extracts and laccase depicted as first derivative of the measured curves (<b>D</b>).</p

Serum biochemistry of control and experimental animals.

<p>Values are expressed as mean ± SEM.</p

HPLC-UV-vis analysis of the unhydrolysed and hydrolysed <i>G verum</i> extract.

<p>(A) Heatmap of the chromatographic profile versus elution time. (<b>B</b>) Chromatograms of the two extracts and of the standards monitored at 320 nm. (<b>C</b>) UV-vis molecular absorption spectra of six of the employed standards.</p

Probing the polyphenolic components and alkali-generated radicals reactivity in the studied extract using EPR spectroscopy.

<p><b>A.</b> Time dependence of such generated radicals between 2 min (dead time due to spectrometer calibration prior measuring) and 20 min, at about 1.8 minutes interval. <b>B.</b> The dominant spectral fingerprint of the chlorogenic acid is visible in the extract with minor contributions of rutin and quercetin. Ferulic and coumaric acids gives no EPR spectrum while treated with sodium hydroxide as described in experimental section. The best fit for the EPR spectrum of the extract was obtained by a linear combination of the identified polyphenols in a 1/30/40 ratio (quercetin/rutin/chlorogenic acid) (model).</p

Phytoconstituent classification based on spectral similarities after chromatographic separation.

<p>Score plots of the first two principal components after applying PCA on the UV-vis mean spectra of the chromatographic peaks obtained by HPLC analysis of <i>G</i>. <i>verum</i> extract prior hydrolysis (<b>A</b>) and after hydrolysis (<b>B</b>). The UV-vis spectra of the two extracts, before separation and the standards are also indicated in both plots. The letter U stands for “unhydrolysed” and indicates compounds specific for this extract; the letter H stands for “hydrolysed” and indicates compounds found only in the hydrolysed extract, while the numbers lacking a letter indicate compounds that are found in both extracts. The number is attributed according to the retention order; the compounds are listed in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0200022#pone.0200022.t002" target="_blank">Table 2</a>.</p